Page: Last modified: 2022-08-17

Code Reference(s):

NBC20 Div.B 9.4.1.1. (first printing)
NBC20 Div.B 9.4.2. (first printing)
NBC20 Div.B 9.20.1. (first printing)
NBC20 Div.B 9.23.1.1. (first printing)
NBC20 Div.B 9.23.3.1. (first printing)
NBC20 Div.B 9.23.3.4. (first printing)
NBC20 Div.B 9.23.3.5. (first printing)
NBC20 Div.B 9.23.6.1. (first printing)
NBC20 Div.B 9.23.11.4. (first printing)
NBC20 Div.B 9.23.13. (first printing)
NBC20 Div.B 9.23.16.1. (first printing)
NBC20 Div.B 9.23.16.5. (first printing)
NBC20 Div.B 9.31.6.2.(3) (first printing)
NBC20 Div.B 9.33.4.7.(2) (first printing)

Subject:
Structural Design (Part 9) ‚ÄĒ Lateral Loads
Title:
Resistance to Lateral Loads
Description:
The proposed change updates the Part 9 provisions for resistance to lateral loads due to earthquakes and wind. It responds to an increase in seismic hazard values for many locations in Canada by replacing Sa(0.2) with the seismic design parameter, Smax, and by defining new wood-frame wall types.
This change could potentially affect the following topic areas:

Problem

Seismic Loads

Changes have been made to seismicity values assigned for locations in Canada listed in Appendix C-2 of the 2015 NBC. The impact is that some regions will require more stringent prescriptive solutions per Part 9 due to the higher spectral hazard values, and there will be more regions with a spectral hazard of Sa(0.2) greater than 1.8; these regions will thus fall outside the limits of the prescriptive solutions in Part 9 and require design per Part 4. Since some more remote areas have difficulties accessing professional engineers, it is proposed that prescriptive requirements be developed for areas where Sa(0.2) is greater than 1.8.

With trends in home construction shifting to open concept‚ÄĒhaving fewer interior partition walls, larger windows and bigger houses‚ÄĒthe once expected redundancy, characteristic of light-frame construction, is becoming less. As such, lateral loads such as those resulting from earthquake and wind could negatively affect houses in low seismic zones, which currently are not required to be braced to resist these loads.

Wind Loads

The threshold for the 1-in-50-year hourly wind pressure (HWP), above which wind needs to be considered in Part 9 of the NBC 2015, is 0.8 kPa. In conducting the analysis to establish new prescriptive provisions for higher seismic hazard proposed for the NBC 2020 a comparison was made to determine the wind pressures that would produce an equivalent base shear for each of the archetypes examined. The results suggested that the minimum trigger of 0.8 kPa was too high and that braced wall bands would be justified for lower triggers of HWP than are currently set in Part 9. It was observed that there were only 7 locations within Canada with a HWP greater than 0.8 kPa listed in Appendix C. It was also observed that the trigger reflected wind speeds similar to wind speeds associated with EF2 level tornadoes.

Also, the NBC 2015 introduced a topographic factor, Ct, which magnifies wind loads for structures located on exposed hills or escarpments. The terrain factor is not taken into account in Part 9 even with the proposed revision.

A design review was conducted to Part 4 requirements for a small house on an exposed coastal hill in Newfoundland where the HWP is listed as 0.78 kPa, indicating it does not require any consideration for wind loads. The design results to Part 4, including the Ct factor, indicated that the design wind pressure was so great that a conventional wood-frame structure could not be constructed to resist the wind loads yet Part 9 requires no consideration for wind in this location. The existing structure on this site shows signs of distress due to wind loads.

Justification

Seismic Loads

The proposed change will add a new band of more stringent prescriptive solutions in Part 9. This will provide prescriptive requirements for areas where the spectral hazard exceeds Sa(0.2) of 1.8.

With changing energy codes where builders are opting to replace wood sheathing with foam sheathing in some locations, and where interior partitions are fewer, windows are larger, and houses are bigger, the experience that Part 9 is based on no longer applies and reconsideration is warranted. In addition, increasingly provinces are recommending bracing for low seismic zones. For example, in the Yukon it is recommended ‚Äúfor low seismic zone‚Ķadoption of all wall distances and minimum wall panel lengths with added total length of braced wall panels in a braced wall band to be roughly 80% of tabulated length if unblocked and 50% of tabulated length if blocked‚ÄĚ. The proposed change is closing a loophole in Part 9 to prevent buildings that could have practically close to zero lateral resistance.

Wind Loads

The proposed change attempts to reduce the large gap between Part 9 and Part 4 provisions and introduces minimum requirements for lateral design to resist wind loads for all regions in Canada.

Considering the current trend for more open concept design of houses, the increase in rare wind events, and the decision to require a minimum consideration for lateral resisting elements for all seismic levels, it was deemed appropriate to provide similar minimum requirements for wind loads.

PROPOSED CHANGE

[9.4.1.1.] 9.4.1.1.General

(See Note A-9.4.1.1.PROPOSED CHANGE A-9.4.1.1. and Article 2.2.7.6. of Division C.)

[1] 1)Subject to the application limitations defined elsewhere in this Part, structural members and their connections shall

[a] a)conform to requirements provided elsewhere in this Part,
[b] b)be designed according to good engineering practice such as that provided in the CWC, ‚ÄúEngineering Guide for Wood Frame Constructions‚ÄĚ,CWC 2014, “Engineering Guide for Wood Frame Construction”, or

[c] c)be designed according to Part 4 using the loads and deflection and vibration limits specified in

[i] i)Part 9, or
[ii] ii)Part 4.
[2] 2)Where floor framing is designed in accordance with Clause (1)(b) or (c), and where supporting wall framing and fastenings, or footings are designed according to Clause (1)(a), the maximum specified live load on the floor according to Table 4.1.5.3. shall not exceed 2.4 kPa.
[3] 3)Location-specific information for structural design, including snow and wind loads and seismic spectral accelerationsthe seismic design parameter, Smax, shall be determined according to Subsection 1.1.3.

 

Note A-9.4.1.1. Structural Design.

Article 9.4.1.1. establishes the principle that the structural members of Part 9 buildings must

  • comply with the prescriptive requirements provided in Part 9,
  • be designed in accordance with accepted good practice, or
  • be designed in accordance with Part 4 using the loads and limits on deflection and vibration specified in Part 9 or Part 4.
Usually a combination of approaches is used. For example, even if the snow load calculation on a wood roof truss is based on Subsection 9.4.2., the joints must be designed in accordance with Part 4. Wall framing may comply with the prescriptive requirements in Subsections 9.23.3., 9.23.10., 9.23.11. and 9.23.12., while the floor framing may be engineered.
Design according to Part 4 or accepted good engineering practice, such as that described in CWC 2014, “Engineering Guide for Wood Frame Construction”,the CWC, ‚ÄúEngineering Guide for Wood Frame Construction‚ÄĚ, requires engineering expertise. The CWC Guide contains alternative solutions and provides information on the applicability of the Part 9 prescriptive structural requirements to further assist designers and building officials to identify the appropriate design approach. The need for professional involvement in the structural design of a building, whether to Part 4 or Part 9 requirements or accepted good practice, is defined by provincial and territorial legislation.

[9.4.2.] 9.4.2. Specified Loads

[9.4.2.1.] 9.4.2.1.Application

[9.4.2.2.] 9.4.2.2.Specified Snow Loads

[9.4.2.3.] 9.4.2.3.Platforms Subject to Snow and Occupancy Loads

[9.4.2.4.] 9.4.2.4.Attics and Roof Spaces

[9.4.2.5.]Seismic Design Parameter

(See Note A-9.4.2.5.)
[1] –)Except as provided in Sentence (2), the value of the seismic design parameter, Smax, at a location listed in Table C-3 of Appendix C shall be taken as Smax for unknown Site Class.
[2] –)Where the Site Class is determined in accordance with Article 4.1.8.4., the value of the seismic design parameter, Smax, at a location listed in Table C-3 of Appendix C, is permitted to be taken as the value for the determined Site Class at that location. (See Note A-9.4.2.5.(2).)

 

 

Note A-9.4.2.5. Seismic Design Parameter.

The seismic design parameter, Smax, is used as a trigger for the application of seismic design provisions in Part 9. It was derived by considering the upper limit on the minimum lateral earthquake force, V, as specified in Clause 4.1.8.11.(2)(c), and is taken as the larger of 2/3 S(0.2) and S(0.5), with S(0.2) and S(0.5) calculated in accordance with Sentence 4.1.8.4.(6).

 

 

 

Note A-9.4.2.5.(2) Determination of Site Class.

To benefit from a refined, and possibly less conservative, value of Smax, the Site Class can be determined on the basis of the ground profile at the site in accordance with Article 4.1.8.4. Determination of the Site Class will require the involvement of a suitably qualified and experienced professional engineer.

 

[9.20.1.] 9.20.1. Application

[9.20.1.1.] 9.20.1.1.General

[1] 1)Except as provided in Article 9.20.1.2., this Section applies to

[a] a)unreinforced masonry and masonry veneer walls not in contact with the ground, where

[i] i)the height of the walls constructed on the foundation walls does not exceed 11 m, and
[ii] ii)the roof or floor assembly above the first storey is not of concrete construction, and

[b] b)flat insulating concrete form walls not in contact with the ground that (see Note A-9.15.1.1.(1)(c) and 9.20.1.1.(1)(b)PROPOSED CHANGE A-9.15.1.1.(1)(c) and 9.20.1.1.(1)(b))

[i] i)have a maximum floor-to-floor height of 3 m,
[ii] ii)are erected in buildings not more than 2 storeys in building height, and
[iii] iii)are erected in locations where the seismic spectral acceleration, Sa(0.2)design parameter, Smax, for Site Class C is not greater than 0.40.27 (see also Article 9.4.2.5.Note A-9.20.1.2.).
[2] 2)For walls other than those described in Sentence (1), or where the masonry walls or insulating concrete form walls not in contact with the ground are designed for specified loads on the basis of ultimate and serviceability limit states, Subsection 4.3.2. shall apply.

[9.20.1.2.] 9.20.1.2.Earthquake Reinforcement

(See Note A-9.20.1.2.also Article 9.4.2.5.)
[1] 1)In locations where the spectral acceleration, Sa(0.2), seismic design parameter, Smax, for Site Class C is greater than 0.550.37, loadbearing elements of masonry buildings more than 1 storey in building height shall be reinforced with not less than the minimum amount of reinforcement required by Subsection 9.20.15.
[2] 2)In locations where the spectral acceleration, Sa(0.2),seismic design parameter, Smax, for Site Class C is greater than 0.350.23 but less than or equal to 0.550.37, loadbearing elements of masonry buildings 3 storeys in building height shall be reinforced with not less than the minimum amount of reinforcement required by Subsection 9.20.15.

[9.23.1.1.] 9.23.1.1.Limitations

(See Note A-9.23.1.1.PROPOSED CHANGE A-9.23.1.1.)

[1] 1)Subject to the application limitations defined elsewhere in this Part, Tthis Section applies to constructions where wall, floor and roof planes are generally comprised of lumber frames of small repetitive structural members, or engineered components, and where

[a] a)roof and wall planes are clad, sheathed or braced on at least one side,
[b] b)the small repetitive structural members are spaced not more than 600 mm o.c.,
[c] c)the constructions do not serve as foundations,
[d] d)the specified live load on supported subfloors and floor framing does not exceed 2.4 kPa, and
[e] e)the span of any structural member does not exceed 12.20 m.
(See Note A-9.23.1.1.(1)PROPOSED CHANGE A-9.23.1.1.(1).)
[2] 2)Where the conditions in Sentence (1) are exceeded for wood constructions, the design of the framing and fastening shall conform to Subsection 4.3.1.

[9.23.3.1.] 9.23.3.1.Standards for Nails and Screws

[1] 1)Except as provided in Sentence (2) and unless otherwise indicated, nails specified in this Section shall be common steel wire nails or common spiral nails conforming to

[a] a)ASTM F1667, “Standard Specification for Driven Fasteners: Nails, Spikes, and Staples”, or
[b] b)CSA B111, “Wire Nails, Spikes and Staples”.
[2] 2)Nails used to comply with Tables 9.23.3.4. and 9.23.3.5.-A to 9.23.3.5.-C shall have a diameter not less than that stated in Table 9.23.3.1. (See Note A-9.23.3.1.(2)PROPOSED CHANGE A-9.23.3.1.(2).)
Table [9.23.3.1.] 9.23.3.1.
Diameter of Nails
Forming Part of Sentence [9.23.3.1.] 9.23.3.1.([2] 2)
Minimum Length of Nails, mm Minimum Diameter of Nails, mm
45 2.64
51 2.84
57 2.87
63 3.25
76 3.66
82 3.66
101 or greater 4.88
[3] 3)Wood screws specified in this Section shall conform to ASME B18.6.1, “Wood Screws (Inch Series)”. (See Note A-9.23.3.1.(3)PROPOSED CHANGE A-9.23.3.1.(3).)

 

Note A-9.23.3.1.(2) Alternative Nail Sizes.

Where power nails or nails with a diameter smaller diameters than that required by Table 9.23.3.4. Tables 9.23.3.1. or 9.23.3.5.-C are used to connect framing, the following equations can be used to determine the required spacing or required number of nails.

The maximum spacing can be reduced using the following equation:

Sadj=StableDredDtable2

where

Sadj
= adjusted nail spacing ? 20 √ó nail diameter,
Stable
= nail spacing required by Table 9.23.3.4. or 9.23.3.5.-A to 9.23.3.5.-C,
Dred
= nail diameter smaller nail diameter than that required by Table 9.23.3.1. or 9.23.3.5.-C, and
Dtable
= nail diameter required by Table 9.23.3.1. or 9.23.3.5.-C.

The number of nails can be increased using the following equation:

Nadj=NtableDtableDred2

where

Nadj
= adjusted number of nails,
Ntable
= number of nails required by Table 9.23.3.4. or 9.23.3.5.-A to 9.23.3.5.-C,
Dtable
= nail diameter required by Table 9.23.3.1. or 9.23.3.5.-C, and
Dred
= smaller nail diameter smaller than that required by Table 9.23.3.1. or 9.23.3.5.-C.
Note that nails should be spaced sufficiently far apart‚ÄĒpreferably no less than 55¬†mm apart‚ÄĒto avoid splitting of framing lumber.

[9.23.3.4.] 9.23.3.4.Nailing of Framing

[1] 1)Except as provided in Sentence (2), nailing of framing shall conform to Table 9.23.3.4.

[2] 2)Where the bottom wall plate or sole plate of an exterior wall is not nailed to floor joists, rim joists or blocking in conformance with Table 9.23.3.4., the exterior wall is permitted to be fastened to the floor framing by

[a] a)having plywood, OSB or waferboard sheathing extend down over floor framing and fastened to the floor framing by nails or staples conforming to Article 9.23.3.5., or

[b] b)tying the wall framing to the floor framing by galvanized-metal strips

[i] i)50 mm wide,
[ii] ii)not less than 0.41 mm thick,
[iii] iii)spaced not more than 1.2 m apart, and
[iv] iv)fastened at each end with at least two 63 mm nails.
Table [9.23.3.4.] 9.23.3.4.
Nailing for Framing
Forming Part of Sentences [9.23.3.4.] 9.23.3.4.([1] 1) and 9.23.14.4.(2)
Construction Detail Minimum Length of Nails, mm Minimum Number or Maximum Spacing of Nails
Floor joist or blocking perpendicular to sill plate or top wall plate below ‚Äď toe nail 82 2 per floor joist or blocking
Rim joist, trimmer joist or blocking ‚Äď supporting walls with required braced wall panels ‚Äď to sill plate or top wall plate ‚Äď toe nail 82 150 mm o.c.
Wood or metal strapping to underside of floor joists 57 2
Cross bridging to joists 57 2 at each end
Double header or trimmer joists 76 300 mm o.c.
Floor joist to stud (balloon construction) 76 2
Ledger strip to wood beam 82 2 per joist
Joist to joist splice (see also Table 9.23.14.8.) 76 2 at each end
Tail joist to adjacent header joist 82 5
(end nailed) around openings
101 3
Each header joist to adjacent trimmer joist 82 5
(end nailed) around openings
101 3
Blocking to stud, or Sstud to wall plate (each end) toe nail 63 4
or end nail
82 2
Doubled studs at openings, or studs at walls or wall intersections and corners 76 750 mm o.c.
Doubled studs at openings, within walls, or abutting studs at wall intersections and corners ‚ÄĒ in required braced wall panels 76 300 mm o.c.
Doubled top wall platesPROPOSED CHANGE Table 9.23.3.4. Footnote (1) 76 600 mm o.c.
Bottom wall plate or sole plate to floor joists, rim joists or blocking (exterior walls)PROPOSED CHANGE Table 9.23.3.4. Footnote (2) 82 400 mm o.c.
Bottom wall plate or sole plate ‚Äď in required braced wall panels ‚Äď to floor joists, rim joists or blocking (exterior walls)PROPOSED CHANGE Table 9.23.3.4. Footnote (2) 82 150 mm o.c.
Interior walls to framing or subflooring 82 600 mm o.c.
Required braced wall panels ‚Äď in interior walls ‚Äď to framing above and below 82 150 mm o.c.
Horizontal member over openings in non-loadbearing walls ‚Äď each end 82 2
Lintels to studs 82 2 at each end
Ceiling joist to plate ‚Äď toe nail each end 82 2
Roof rafter, roof truss or roof joist to plate ‚Äď toe nailPROPOSED CHANGE Table 9.23.3.4. Footnote (3) 82 3
Rafter plate to each ceiling joist 101 2
Rafter to joist (with ridge supported) 76 3
Rafter to joist (with ridge unsupported) 76 see Table 9.23.14.8.
Gusset plate to each rafter at peak 57 4
Rafter to ridge board ‚Äď toe nail ‚Äď end nail 82 3
Collar tie to rafter ‚Äď each end 76 3
Collar tie lateral support to each collar tie 57 2
Jack rafter to hip or valley rafter 82 2
Roof strut to rafter 76 3
Roof strut to loadbearing wall ‚Äď toe nail 82 2
38 mm × 140 mm  or less plank decking to support 82 2
Plank decking wider than 38 mm  × 140 mm to support 82 3
38 mm edge laid plank decking to support (toe nail) 76 1
38 mm edge laid plank to each other 76 450 mm o.c.
End-joist or end-rafter to built-up wall studPROPOSED CHANGE Table 9.23.3.4. Footnote (4) 76 5 or 8PROPOSED CHANGE Table 9.23.3.4. Footnote (5)
[3] 3)Where the 1-in-50 hourly wind pressure is equal to or greater than 0.8 kPa, roof rafters, joists or trusses shall be tied to the wall framing with connectors that will resist a factored uplift load of 3 kN.

[4] 4)Galvanized-steel straps are deemed to comply with Sentence (3), provided they are

[a] a)50 mm wide,
[b] b)not less than 0.91 mm thick, and
[c] c)fastened at each end with at least four 63 mm nails.

[9.23.3.5.] 9.23.3.5.Fasteners for Sheathing or Subflooring

[1] 1)Except as provided in Sentence (2) to (4), fFastening forof wall sheathing not in required braced wall panels, roof sheathing where the 1-in-50-year hourly wind pressure (HWP) is less than or equal to 0.6 kPa and where Smax is less than or equal to 0.47 for Site Class C, and subflooring shall conform to Table 9.23.3.5.-A.
Table [9.23.3.5.-A] 9.23.3.5.-A
Fasteners for Subflooring and forWall Sheathing not in Required Braced Wall Panels, for Roof Sheathing where the 1-in-50 HWP < 0.8? 0.6 kPa and Sa(0.2) ? 0.70Smax ? 0.47 (for Site Class C), and for Subflooring
Forming Part of Sentence [9.23.3.5.] 9.23.3.5.([1] 1)
Element Minimum Length of Fasteners, mm Minimum Number or Maximum Spacing of Fasteners
Common or Spiral Nails Ring Thread Nails or Screws Roofing Nails Staples
Board lumber 184 mm or less wide 51 45 n/a 51 2 per support
Board lumber more than 184 mm wide 51 45 n/a 51 3 per support
Fibreboard sheathing up to 13 mm thick n/a n/a 44 28 150 mm o.c. along edges and 300 mm o.c. along intermediate supports
Gypsum sheathing up to  13 mm thick n/a n/a 44 n/a
Plywood, OSB or waferboard up to 10 mm thick
51 45 n/a 38
Plywood, OSB or waferboard over 10 mm and up to 20 mm thick
51 45 n/a 51
Plywood, OSB or waferboard over 20 mm and up to 25 mm thick
57 51 n/a n/a

[2] 2)Except as provided in Sentence (4), Ffastening of roof sheathing and sheathing in required braced wall panels shall conform toTable 9.23.3.5.-B, where the

[a] –)the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.80.6 kPa and less but not greater than 1.2 kPa and the seismic spectral acceleration, Sa(0.2), is not more than 0.90, or
[b] –)the seismic spectral accelerationdesign parameter, Sa(0.2)Smax, is greater than 0.700.47 for Site Class C but not greaterand not more than 0.902.6.
Table [9.23.3.5.-B] 9.23.3.5.-B
Fasteningers forof Roof Sheathing where 0.8 kPa ? 1-in-500.6 kPa < HWP <? 1.2 kPa andor 0.47 (for Site Class C) < Smax ? 2.6 Sa(0.2) ? 0.90 or where 0.70 < Sa(0.2) ? 0.90
Forming Part of Sentence [9.23.3.5.] 9.23.3.5.([2] 2)
HWP and Smax Limits Element Minimum Length of Fasteners, mm Minimum Number or Maximum Spacing of FastenersPROPOSED CHANGE Table 9.23.3.5.B. Footnote (1)
Common, Spiral or Ring Thread Nails Screws 14‚Äďgauge staples
0.6 kPa < HWP ? 0.8 kPa and Smax ? 0.6

or

 

Board lumber 184 mm or less widePROPOSED CHANGE Table 9.23.3.5.B. Footnote (3) 63 51 63 2 per support
Board lumber more than 184 mm widePROPOSED CHANGE Table 9.23.3.5.B. Footnote (3) 63 51 63 3 per support
Plywood, OSB or waferboard up to 20 mm thick 63 51 63 150 mm o.c. along the edges of sheathing panels and 300 mm o.c. along intermediate supports; and for roof sheathing where HWP is equal to or greater than 0.8 kPa and less than 1.2 kPa, and 50 mm o.c. within 1 m of the edges of the roof
Plywood, OSB or waferboard over 20 mm and up to 25 mm thick 63 57 n/a
0.8 kPa < HWP ? 1.2 kPa and Smax ? 2.6

or
0.6 < Smax ? 2.6

 

Plywood, OSB or waferboard up to 20 mm thick 63 51 n/a 75 mm o.c. along the edges of sheathing panels, 300 mm o.c. along intermediate supports, and where HWP is equal to or greater than 0.8 kPa and less than 1.2 kPa, 50 mm o.c. within 1 m of the edges of the roof
Plywood, OSB or waferboard over 20 mm and up to 25 mm thick 63 57 n/a

[3] 3)Except as provided in Sentence (4), fFastening of roof sheathing and wall sheathing in required braced wall panels shall conform to the reference framing types specified in Table 9.23.3.5.-C, where.

[a] –)the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.8 kPa and less than 1.2 kPa and the spectral acceleration, Sa(0.2), is not more than 1.8, or
[b] –)the seismic spectral acceleration, Sa(0.2), is greater than 0.90 and not more than 1.8.
Table [9.23.3.5.-C]
Fastening of Wall Sheathing in Required Braced Wall Panels where HWP < 1.2 kPa or Smax ? 2.6
Forming Part of Sentence [9.23.3.5.] 9.23.3.5.([3] 3)
Reference framing typePROPOSED CHANGE Table Footnote (1) Minimum Sheathing ElementPROPOSED CHANGE Table Footnote (2)and Maximum Stud Spacing Minimum Specification of Fasteners (mm) Minimum Number or Maximum Spacing of Fasteners PROPOSED CHANGE Table Footnote (3) at Panel Edges to Framing
Common, Spiral or Ring Thread Nails Screws
GWB-O 12.5 mm gypsum for 600 mm stud spacing 2.48 mm diameter ring thread with 20 mm penetration into support framingPROPOSED CHANGE Table Footnote (4) 3.45 mm shank diameter Type W with 20 mm penetration into support framingPROPOSED CHANGE Table Footnote (5) 200 mm o.c. for nails

300 mm o.c. for screws

 

GWB-A 12.5 mm gypsum for 600 mm stud spacing 200 mm o.c for nails

300 mm o.c. for screws

 

GWB-B 12.5¬†mm gypsum for 400¬†mm stud spacing  

200 mm o.c.

 

GWB-C 12.5 mm gypsum for 400 mm stud spacing or 12.5 mm gypsum for 600 mm stud spacing, blockedPROPOSED CHANGE Table Footnote (6) 150 mm o.c. or 200 mm o.c. for blocked
GWB-D 12.5 mm gypsum for 400 mm stud spacing 100 mm o.c.
WSP-A 9.5 mm plywood, OSB or waferboard for 400 mm stud spacing 2.84 mm x 51 mmPROPOSED CHANGE Table Footnote (7) NPPROPOSED CHANGE Table Footnote (8) 150 mm o.c.
WSP-B 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (6) for 600 mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (7) NPPROPOSED CHANGE Table Footnote (8) 150 mm o.c.
WSP-C 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (6) for 600 mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (7) NPPROPOSED CHANGE Table Footnote (8) 100 mm o.c.
WSP-D 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (6) for 600 mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (7) NPPROPOSED CHANGE Table Footnote (8) 75 mm o.c.
WSP-E 15.5 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (6) for 600 mm stud spacing 3.66 mm x 76 mmPROPOSED CHANGE Table Footnote (7) NPPROPOSED CHANGE Table Footnote (8) 75 mm o.c.
DWB 19 mm diagonal lumber board 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (7) 3.25 mm x 51 mmPROPOSED CHANGE Table Footnote (7) 2 per support framing where lumber width ? 184 mm

or
3 per support framing where lumber width > 184 mm

 

Table [9.23.3.5.-D]
Fasteners for Sheathing where 0.8 kPa ? 1-in-50 HWP < 1.2 kPa and Sa(0.2) ? 1.8 or where 0.90 < Sa(0.2) ? 1.8
Forming Part of Sentence [9.23.3.5.] 9.23.3.5.([3] 3)
Element Minimum Length of Fasteners, mm Minimum Number or Maximum Spacing of Fasteners
Common, Spiral or Ring Thread Nails Screws
Plywood, OSB or waferboard up to 20 mm thickPROPOSED CHANGE Table Footnote (1) 63 51 75 mm o.c. along edges and 300 mm o.c. along intermediate supports; and for roof sheathing where 1-in-50 HWP is equal to or greater than 0.8 kPa and less than 1.2 kPa, 50 mm o.c. within 1 m of the edges of the roof
Plywood, OSB or waferboard over 20 mm and up to 25 mm thick 63 57

[4] 4)Fastening of wall sheathing in required braced wall panels and roof sheathing shall conform to Part 4,

[a] a)where the 1-in-50-year hourly wind pressure is greater than 1.2 kPa, or
[b] –)for required braced wall panels, where the seismic spectral acceleration, Sa(0.2), is greater than 1.8.
[c] b)where the seismic design parameter, Smax, is greater than 2.6, or

[d] –)for buildings of 3 storeys in building height where the seismic design parameter, Smax, is greater than 0.47 for Site Class C and

[i] –)of heavy weight construction,
[ii] –)clad with masonry veneer, or
[iii] –)clad with stone veneer.

 

(See Sentence 9.23.13.2.(3)-NEW)
[5] 5)Staples shall not be less than 1.6 mm in diameter or thickness, with not less than a 9.5 mm crown driven with the crown parallel to framing.
[6] 6)Roofing nails for the attachment of fibreboard or gypsum sheathing shall not be less than 3.2 mm in diameter with a minimum head diameter of 11.1 mm.
[7] 7)Flooring screws shall not be less than 3.2 mm in diameter.

[8] 8)The edges of sheathing in a braced wall panel shall be supported and fastened to wood blocking where

[a] a)the seismic spectral acceleration, Sa(0.2), is greater than 1.2, or
[b] b)the braced wall panel supports more than a roof of lightweight construction.

 

 

 

Note A-Tables 9.23.3.5.-C and -D Anchor Bolt Spacing.

Anchor bolts fasten the sill plates of the required braced wall panels to the foundation. The anchor bolt spacing necessary to resist the anticipated seismic load is calculated based on the shear resistance of the panels with an overstrength-related force modification factor, Ro, of 1.2.

 

 

 

Note A-Table 9.23.3.5.-C Factored Shear Resistances and Framing Adjustment Factors.

Table 9.23.3.5.-C describes the fastening of sheathing elements for each reference framing type available for use as a braced wall panel. There are three categories of framing type: wood-sheathed braced wall panels (WSP), diagonal (lumber) wood boards (DWB), and gypsum board (GWB). Table A-9.23.3.5.-C provides the factored shear resistances as per CSA O86 and framing adjustment factors of the framing types listed in Table 9.23.3.5.-C, as well as alternative framing types not listed in Table 9.23.3.5.-C, and can be used to calculate the minimum required length of braced wall panels using the alternative calculation procedures in Note A-9.23.13.7.(3)‚Äď2020 and A- 9.23.13.7.(4)‚Äď2020.
Table [Table 9.23.3.5.-C] A-9.23.3.5.-C
Factored Shear Resistances and Framing Adjustment Factors of Framing Types
Reference Framing Type Minimum Sheathing ElementPROPOSED CHANGE Table Footnote (1) Minimum Specification of Fasteners, mm Minimum Number or Maximum Spacing of FastenersPROPOSED CHANGE Table Footnote (2) at Panel Edges to Framing KWframePROPOSED CHANGE Table Footnote (3) KSframePROPOSED CHANGE Table Footnote (4) Factored shear resistance, kN/m
Common, Spiral or Ring Thread Screws
GWB-O (interior side of WSP framing types) 12.5 mm gypsum for 600 mm stud spacing 2.48 mm diameter ring thread with 20 mm penetration into support framingPROPOSED CHANGE Table Footnote (5) 3.45 mm shank diameter Type W with 20 mm penetration into support framingPROPOSED CHANGE Table Footnote (6) 200 mm o.c. for nail

300 mm o.c. for screw

 

n/a n/a 0.61PROPOSED CHANGE Table Footnote (7)
GWB-A 12.5 mm gypsum for 600 mm stud spacing 200 mm o.c. for nail

300 mm o.c. for screw

 

2.85 4.28 1.15PROPOSED CHANGE Table Footnote (8)
GWB-B 12.5 mm gypsum for 400 mm stud spacing 150 mm o.c.

or

200 mm o.c. for blocked

1.65 2.48 1.98PROPOSED CHANGE Table Footnote (8)
GWB-C 12.5 mm gypsum for 400 mm stud spacing or

12.5 mm gypsum for 600 mm stud spacing, blockedPROPOSED CHANGE Table Footnote (9)

 

150 mm o.c. or

200 mm o.c. for blocked

 

1.23 1.84 2.67PROPOSED CHANGE Table Footnote (8)
GWB-D 12.5 mm gypsum for 400 mm stud spacing 100 mm o.c. 1.00 1.50 3.28PROPOSED CHANGE Table Footnote (8)
WSP-A 9.5 mm plywood, OSB or waferboard for 400mm stud spacing 2.84 mm x 51 mmPROPOSED CHANGE Table Footnote (10) NPPROPOSED CHANGE Table Footnote (11) 150 mm o.c. 1.00 1.00 3.28PROPOSED CHANGE Table Footnote (7)
WSP-B 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (9) for 600mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (10) NPPROPOSED CHANGE Table Footnote (11) 150 mm o.c. 0.53 0.53 6.22PROPOSED CHANGE Table Footnote (7)
WSP-C 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (9) for 600mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (10) NP(10) 100 mm o.c. 0.46 0.46 7.15PROPOSED CHANGE Table Footnote (7)
WSP-D 11 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (9) for 600mm stud spacing 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (10) NPPROPOSED CHANGE Table Footnote (11) 75 mm o.c. 0.42 0.42 7.85PROPOSED CHANGE Table Footnote (7)
WSP-E 15.5 mm plywood, OSB or waferboard, blockedPROPOSED CHANGE Table Footnote (9) for 600mm stud spacing 3.66 mm x 63 mmPROPOSED CHANGE Table Footnote (10) NPPROPOSED CHANGE Table Footnote (11) 75 mm o.c. 0.38 0.38 8.71PROPOSED CHANGE Table Footnote (7)
DWB 19 mm diagonal lumber board 3.25 mm x 63 mmPROPOSED CHANGE Table Footnote (10) 3.25 mm x 51 mmPROPOSED CHANGE Table Footnote (11) 2 per support framing where lumber width ? 184 mm

3 per support framing where lumber width > 184 mm

 

0.57 0.57 5.77PROPOSED CHANGE Table Footnote (7)

 

[9.23.6.1.] 9.23.6.1.Anchorage of Building Frames

[1] 1)Except as required by Sentence 9.23.6.3.(1), building frames shall be anchored to the foundation unless a structural analysis that considers wind and earthquake loads and lateral earth pressures shows that anchorage is not required.

[2] 2)Except as provided in Sentences (3) to (65), anchorage shall be provided by

[a] a)embedding the ends of the first floor joists in concrete, or
[b] b)fastening the sill plate to the foundation with not less than 12.7 mm diam anchor bolts spaced not more than 2.4 m o.c.

[3] 4)For buildings with 2 or more floors supported by frame walls that are in areas where the seismic spectral acceleration, Sa(0.2), is not greater than 0.70 or the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.80 kPa but not greater than 1.20 kPa, aAnchorage at braced wall panels shall be provided by fastening the sill plate to the foundation with

[a] a)not less than 15.9 mm in diameter, located two anchor bolts per braced wall panel, each located at opposite ends of the braced wall panel within 0.5 m of the foundation end of the foundation, and spaced not more than 2.4 m o.c, or within 0.3 m from the end of the braced wall panel, and
[b] b)not less than 12.7¬†mm in diameter, located within 0.5¬†m of the end of the foundation, and spaced not more than 1.7¬†m¬†o.c.anchor bolts spaced in accordance with Table 9.23.6.1. (See Note A‚Äď9.23.6.1.(3))
[4] 4)For buildings supported by frame walls that are in areas where the seismic spectral acceleration, Sa(0.2), is greater than 0.70 but not greater than 1.8 and the 1-in-50 hourly wind pressure (HWP) is not greater than 1.20 kPa, anchorage shall be provided by fastening the sill plate to the foundation with not less than two anchor bolts per braced wall panel located within 0.5 m of the end of the foundation and spaced in accordance with Table 9.23.6.1.
Table [9.23.6.1.-A]
Anchor Bolt Spacing within Braced Wall Panels where either the 0.6 kPa < 1‚Äďin-50 HWP ? 1.20 kPa and 0.70 < Sa(0.2) ? 1.8or 0.47 (for Site Class C) < Smax ? 2.6PROPOSED CHANGE Table Footnote (1)
Reference Framing Type Maximum Spacing of Anchor Bolts along Braced Wall Band, m
Anchor Bolt Diameter, mm
12.7 mm 15.9 mm
GWB-A 2.4 2.4
GWB-B 2.4 2.4
GWB-C 1.8 2.4
GWB-D 1.4 2.1
WSP-A 1.4 2.1
WSP-B 0.8 1.2
WSP-C 0.7 1.0
WSP-D 0.6 0.9
WSP-E 0.5 0.8
DWB 0.8 1.2
Anchor Bolt Diameter, mm Sa(0.2) Maximum Spacing of Anchor Bolts Along Braced Wall Band, m
Light Construction Heavy ConstructionPROPOSED CHANGE Table Footnote (1)
Number of Floors SupportedPROPOSED CHANGE Table Footnote (2)
1 2 3 1 2
12.7 0.70 < Sa(0.2) ? 0.80 2.4 2.3 1.8 2.4 2.0
0.80 < Sa(0.2) ? 0.90 2.4 2.3 1.8 2.4 2.0
0.90 < Sa(0.2) ? 1.0 2.4 2.2 1.5 2.4 1.8
1.0 < Sa(0.2) ? 1.1 2.4 2.1 1.4 2.4 1.6
1.1 < Sa(0.2) ? 1.2 2.4 2.0 1.3 2.4 1.5
1.2 < Sa(0.2) ? 1.3 2.4 1.9 1.3 2.4 1.5
1.3 < Sa(0.2) ? 1.35 2.4 1.8 1.2 2.3 1.4
1.35 < Sa(0.2) ? 1.8 2.4 1.8 1.1 2.3 1.4
15.9Table9.23.6.1 0.70 < Sa(0.2) ? 0.80 2.4 2.4 2.2 2.4 2.4
0.80 < Sa(0.2) ? 0.90 2.4 2.4 2.2 2.4 2.4
0.90 < Sa(0.2) ? 1.0 2.4 2.4 2.1 2.4 2.3
1.0 < Sa(0.2) ? 1.1 2.4 2.4 1.9 2.4 2.3
1.1 < Sa(0.2) ? 1.2 2.4 2.4 1.9 2.4 2.2
1.2 < Sa(0.2) ? 1.3 2.4 2.4 1.8 2.4 2.1
1.3 < Sa(0.2) ? 1.35 2.4 2.3 1.7 2.4 2.0
1.35 < Sa(0.2) ? 1.8 2.4 2.2 1.6 2.4 1.9

[5] 5)Anchor bolts referred to in Sentences (2) and (34) shall be

[a] a)fastened to the sill plate with nuts and washers,
[b] b)embedded not less than 100 mm in the foundation, and
[c] c)so designed that they may be tightened without withdrawing them from the foundation.

[6] 6) Anchorage shall be designed according to Part 4

[a] –)where the 1-in-50-year hourly wind pressure (HWP) is greater than 1.2¬†kPa,
[b] –)where the seismic design parameter, Smax, is greater than 2.6, or

[c] –)for buildings of 3 storeys in building height, where the seismic design parameter, Smax, is greater than 0.47 for Site Class C and

[i] –)of heavy weight construction,
[ii] –)clad with masonry veneer, or
[iii] –)clad with stone veneer.

(See Sentence 9.23.13.2.(3))

 

[7] 6)Where the seismic spectral acceleration, Sa(0.2), is greater than 1.8 or the 1-in-50 hourly wind pressure is equal to or greater than 1.2 kPa, anchorage shall be designed according to Part 4.

 

 

Note A-9.23.6.1.(3) Anchorage of Building Frames.

Figure [A-9.23.6.1.(3)]
Anchorage of Building Frames
Anchorage of Building Frames

 

[9.23.11.4.] 9.23.11.4.Joints in Top Plates

[1] 1)Joints in the top plates of loadbearing walls shall be staggered not less than one stud spacing.

[a] –)one stud spacing where the number of nails required in accordance with Sentence (5) is 16 or less,
[b] –)two stud spacings where the number of nails required in accordance with Sentence (5) is greater than 16 and not more than 32, or
[c] –)three stud spacings where the number of nails required in accordance with Sentence (5) is greater than 32.
[2] 2)The top plates in loadbearing walls shall be lapped or otherwise tied at corners and intersecting walls in accordance with Sentence (4).
[3] 3)Joints in single top plates used with loadbearing walls shall be tied in accordance with Sentence (4).
[4] 4)Ties referred to in Sentences (2) and (3) shall be the equivalent of not less than 75 mm by 150 mm by 0.91 mm thick galvanized steel nailed to each wall with at least three 63 mm nails.
[5] 5)Where the seismic spectral acceleration, Sa(0.2), is greater than 0.70 but not more than 1.8, doubled top plates in braced wall bands shall be fastened on each side of a splice with 76 mm long common steel wire nails or spiral nails in accordance with Table 9.23.11.4.
Table [9.23.11.4.-A] 9.23.11.4.
Fasteners in Doubled Top Plate Splice Connections in Braced Wall Bands where 0.70 < Sa(0.2) ? 1.8
Forming Part of Sentence [9.23.11.4. 9.23.11.4.] 9.23.11.4.([5 6] 5)
Sa(0.2) Minimum Number of Nails on Each Side of Doubled Top Plate Splice
Light Construction Heavy ConstructionPROPOSED CHANGE Table 9.23.11.4. Footnote (1)
Number of Supported FloorsPROPOSED CHANGE Table 9.23.11.4. Footnote (2)
0 1 2 0 1
0.70 < Sa(0.2) ? 0.80 2 5 8 3 8
0.80 < Sa(0.2) ? 0.90 2 5 8 4 8
0.90 < Sa(0.2) ? 1.0 3 6 10 4 10
1.0 < Sa(0.2) ? 1.1 3 7 11 5 11
1.1 < Sa(0.2) ? 1.2 3 7 11 5 12
1.2 < Sa(0.2) ? 1.3 3 8 12 5 12
1.3 < Sa(0.2) ? 1.35 4 8 12 5 13
1.35 < Sa(0.2) ? 1.8 4 8 13 5 13
[6] 5)Except as provided in Sentence (7), doubled top plates in braced wall bands shall be fastened on each side of a splice with 76 mm long common steel wire nails or spiral nails in accordance with Table 9.23.11.4. and Table 9.23.11.4.-B whichever governs. (See Note A-Table 9.23.11.4.-B.)
Table [9.23.11.4.-B] 9.23.11.4.
Fasteners in Doubled Top Plate Splice Connections in Braced Wall Bands where 0.70 < Sa(0.2) ? 1.80.47 (for Site Class C) < Smax ? 2.6PROPOSED CHANGE Table 9.23.11.4. Footnote (1)
Forming Part of Sentence [9.23.11.4. 9.23.11.4.] 9.23.11.4.([5 6] 5)
Smax Minimum Number of Nails on Each Side of Doubled Top Plate Splice for Braced Wall Band Spacing of 10.6 mPROPOSED CHANGE Table 9.23.11.4. Footnote (2)
Construction Weight ClassificationPROPOSED CHANGE Table 9.23.11.4. Footnote (3)
Normal Weight Heavy WeightPROPOSED CHANGE Table 9.23.11.4. Footnote (4) Masonry Veneer (one or more faces)PROPOSED CHANGE Table 9.23.11.4. Footnote (6) Stone Veneer (one or more faces)PROPOSED CHANGE Table 9.23.11.4. Footnote (6)
? 0.60 4 7 8 10
0.6 < and ? 0.8 6 8 9 12
0.8 < and ? 1.2 9 12 14 19
1.2 < and ? 1.6 12 16 19 25
1.6 < and ? 2.0 14 20 23 31
2.0 < and ? 2.6 19 25 30 40
Table [9.23.11.4.-C]
Fasteners in Double Top Plate Splice Connections in Braced Wall Bands Where 0.6 kPa < HWP ? 1.2 kPa
Forming¬†Part¬†of¬†Sentence¬†— (–)
HWP Minimum Number of Nails on Each Side of Doubled Top Plate Splice for Braced Wall Band spacing of 10.6 mPROPOSED CHANGE Table Footnote (1)
Rough ExposurePROPOSED CHANGE Table Footnote (2), 3m roof eave-to-ridge heightPROPOSED CHANGE Table Footnote (3)
? 0.3 7
0.3 < and ? 0.4 9
0.4 < and ? 0.5 11
0.5 < and ? 0.6 13
0.6 < and ? 0.9 20
0.9 < and ? 1.2 26
[7] –)Nails referred to in Sentence (5) shall be spaced not less than 75 mm o.c. along the top plate in rows spaced not less than 35 mm.

[8] –)Doubled top plates in braced wall bands shall be designed according to Part 4 where the

[a] –)1‚Äďin-50‚Äďyear hourly wind pressure (HWP) is greater than 1.2 kPa,
[b] –)seismic design parameter, Smax, is greater than 2.6, or

[c] –)seismic design parameter, Smax, is greater than 0.47 for Site Class C for buildings of 3 storeys in building height and

[i] –)of heavy weight construction,
[ii] –)clad with masonry veneer, or
[iii] –)clad with stone veneer.

 

 

[9.23.13.] 9.23.13. Bracing to Resist Lateral Loads Due to Wind and Earthquake

[9.23.13.1.] 9.23.13.1.Requirements for Low to Moderate Wind and Seismic Forces

(See Note A-9.23.13.1.PROPOSED CHANGE A-9.23.13.1.)

[1] 1)This Article applies in locations where the seismic spectral acceleration, Sa(0.2), is not more than 0.70 and the 1-in-50 hourly wind pressure is less than 0.80 kPa.

[a] –)seismic design parameter, Smax, for Site Class C, is not more than 0.47 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.60 kPa.
[b] –)unsupported height of the braced wall panels in the building is not greater than 3.1 m, and
[c] –)lowest exterior frame wall supports a roof and not more than 2 floors.

[2] 2)Bracing to resist lateral loads shall be designed and constructed as followsin accordance with:

[a] a)exterior walls shall bethe simplified approach outlined in Article 9.23.13.11., where the seismic design parameter, Smax, is not greater than 0.47, and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.60 kPa,

[i] i)clad with panel-type cladding in accordance with Section 9.27.,
[ii] ii)sheathed with plywood, OSB, waferboard, fibreboard, gypsum board or diagonal lumber sheathing complying with Subsection 9.23.17. and fastened in accordance with Table 9.23.3.5.-A, or
[iii] iii)finished on the interior with a panel-type material in accordance with the requirements of Section 9.29., or

[b] b)in accordance withArticles 9.23.13.4. to 9.23.13.10.,

[i] i)Articles 9.23.13.4. to 9.23.13.7.,
[ii] ii)Part 4, or
[iii] iii)good engineering practice such as that provided in CWC 2014, “Engineering Guide for Wood Frame Construction”.
[c] –)Part 4, or
[d] –)good engineering practice such as that provided in CWC, ‚ÄúEngineering Guide for Wood Frame Construction.‚ÄĚ

[9.23.13.2.] 9.23.13.2.Requirements for High Wind and Seismic Forces

[1] 1)Except as provided in Article 9.23.13.1., this Article applies in locations where the

[a] a)unsupported height of the braced wall panels in the building is not greater than 3.1 m,
[b] b)1-in-50 year hourly wind pressure (HWP) is not greater than 1.2 kPa, and the lowest exterior frame wall supports a roof and not more than 2 floors, and

[c] a)the seismic spectral accelerationdesign parameter, SmaxSa(0.2), is greater than 0.70 but not more than 1.82.6 and the lowest exterior frame wall supports a roof and not more than

[i] i)the lowest exterior frame wall supports not more than 21 floor in buildings constructed using normal weightof heavy construction (see Note A-9.23.13.2.(1)(a)(i)PROPOSED CHANGE A-9.23.13.2.(1)(a)(i)), or
[ii] ii)the lowest exterior frame wall supports not more than 21 floors in other types ofbuildings constructed with heavy weight construction or clad with masonry veneer or stone veneer., and
[d] b)the 1-in-50 hourly wind pressure is less than 1.20 kPa.

[2] 2)Bracing to resist lateral loads shall be designed and constructed in accordance with

[a] a)Articles 9.23.13.4. to 9.23.13.7.7.
[b] b)Part 4, or
[c] c)good engineering practice such as that provided in CWC 2014, “Engineering Guide for Wood Frame Construction”.CWC, ‚ÄúEngineering Guide for Wood Frame Construction.‚ÄĚ

[3] –)For the purposes of Sentence (1) and Subsections 9.23.13.5., 9.23.5., 9.23.6. and 9.23.11., in a building

[a] –)of normal weight construction, the average dead weight per storey shall not exceed

[i] –)0.5 kPa for floors and 0.5 kPa for partitions and interior walls,
[ii] –)0.5 kPa for the roof, or
[iii] –)0.4 kPa for exterior walls,

 

[b] –)of heavy weight construction, the average dead weight per storey shall conform to Clause (a), except that the average dead weight per storey shall not exceed

[i] –)1.5 kPa for floors and 0.5 kPa for partitions and interior walls,
[ii] –)1.0 kPa for the roof, or
[iii] –)1.2 kPa for exterior walls,

 

[c] –)clad with masonry veneer the average dead weight of the masonry veneer shall not exceed 1.9 kPa, and
[d] –)clad with stone veneer the average dead weight of the stone veneer shall not exceed 3.2 kPa.
(See Note A-9.23.13.2.(3))

 

[9.23.13.3.] 9.23.13.3.Requirements for Extreme Wind and Seismic Forces

[1] 1)Except as provide in Articles 9.23.13.1 and 9.23.13.2 Articles 9.23.13.1. and 9.23.13.2., this Article applies in locations where

[a] a)the seismic spectral acceleration, Sa(0.2), is

[i] i)greater than 1.8,
[ii] ii)greater than 0.70 and the lowest exterior frame wall supports more than 2 floors in buildings of light construction, or
[iii] iii)greater than 0.70 and the lowest exterior frame wall supports more than 1 floor in buildings of heavy construction, or

 

[b] a)the 1-in-50 hourly wind pressure is equal to or greater than 1.2 kPa., or

[c] b)the seismic design parameter, Smax, is greater than

[i] –)2.6, or
[ii] –)0.47 (for Site Class C) and the lowest exterior frame wall supports a roof and more than 1 floor in buildings constructed with heavy weight construction, or clad with masonry veneer or stone veneer.

 

[2] 2)Bracing to resist lateral loads shall be designed and constructed in accordance with

[a] a)Part 4, or
[b] b)good engineering practice such as that provided in CWC 2014, “Engineering Guide for Wood Frame Construction”.CWC, ‚ÄúEnigeering Guide for Wood Frame Construction.‚ÄĚ

[9.23.13.4.] 9.23.13.4.Braced Wall Bands

(See Note A-9.23.13.4.PROPOSED CHANGE A-9.23.13.4.)

[1] 1)Braced wall bands shall

[a] –)surround the perimeter of the building,
[b] a)be full storey height,
[c] b)be not more than 1.2 m wide,
[d] c)lap at both ends with another braced wall band,
[e] d)be aligned with braced wall bands on storeys above and below, and
[f] e)conform to the spacing and dimensions given in Table 9.23.13.5. and Article 9.23.13.7.-2020
[2] 2)The perimeter of the building shall be located within braced wall bands.
[3] 3)For split-level buildings, a braced wall band shall be located where there is a change in floor level greater than the depth of one floor joist.

[9.23.13.5.] 9.23.13.5.Braced Wall Panels in Braced Wall Bands

[1] 1)Except as provided in Sentences (2) to (5) and 9.23.13.10.(2) to (4) and Article 9.23.13.7.-2025, braced wall panels shall

[a] a)be located within braced wall bands,
[b] –)be laterally supported at each floor level and the roof,
[c] b)extend, as applicable, from the top of the supporting footing, slab or subfloor to the underside of the floor, ceiling or roof framing above, and
[d] c)conform to the spacing and dimensions given in Table 9.23.13.5. and Article 9.23.13.7.-2025
Table [9.23.13.5.] 9.23.13.5.
Spacing and Dimensions of Braced Wall Bands and Braced Wall Panels
Forming Part of Sentences [9.23.13.4.] 9.23.13.4.([1] 1) and [9.23.13.5.] 9.23.13.5.([1] 1)
Description Spacing and Dimensions of Braced Wall Bands and Braced Wall PanelsPROPOSED CHANGE Table 9.23.13.5. Footnote (1)PROPOSED CHANGE Table 9.23.13.5. Footnote (2)PROPOSED CHANGE Table 9.23.13.5. Footnote (3)
Seismic and Wind Loads
Smax < 1.0 and HWP < 0.9 kPa 1.0 < Smax ? 2.6 or
0.9 ? HWP ? 1.2 kPa
Maximum distance between centre lines of adjacent braced wall bands measured from the furthest points between centres of the bandsPROPOSED CHANGE Table 9.23.13.5. Footnote (4) 10.6 m 7.6 m
Maximum distance between required braced wall panels measured from the edges of the panels 6.4 m 6.4 m
Maximum distance from the end of a braced wall band to the edge of the closest required braced wall panel 2.4 m 2.4 m
Minimum length of individual wood-sheathed braced wall panels:
‚ÄĘ panel located at the end of a braced wall band where the braced wall panel connects to an intersecting braced wall panel
600 mm 600 mm
‚ÄĘ panel not located at the end of a braced wall band or braced wall panel located at the end of a braced wall band where the braced wall panel does not connect to an intersecting braced wall panel
750 mm 750 mm
Minimum length of individual braced wall panels sheathed only with gypsum board: 1.2 m
Minimum length of individual diagonal lumber sheathed braced wall panels: 1.2 m
Minimum total length of all braced wall panels in a braced wall band Per Article 9.23.13.7.-2020
Minimum total length of all braced wall panels in a braced wall band
‚ÄĘ supporting 3 floors, light construction
75% of length of braced wall band
‚ÄĘ supporting 2 floors, heavy constructionPROPOSED CHANGE Table 9.23.13.5. Footnote (5)
75% of length of braced wall band
‚ÄĘ supporting 2 floors, light construction
40% of length of braced wall band
‚ÄĘ supporting 1 floor, heavy constructionPROPOSED CHANGE Table 9.23.13.5. Footnote (5)
40% of length of braced wall band
‚ÄĘ supporting 1 floor, light construction
25% of length of braced wall band
‚ÄĘ not supporting a floor
25% of length of braced wall band

[2] 2)In basements or crawl spaces where the perimeter foundation walls extend from the footings to the underside of the supported floor, braced wall bands constructed with braced wall panels shall, at minimum, be of a total length equal to the length of the braced wall panel in the braced wall band in the storey above and spaced not more than

[a] a) 15 m from the perimeter foundation walls,
[b] b) 15 m from interior foundation walls, and
[c] c) 15 m from adjacent braced wall bands constructed with braced wall panels.
(See Note A-9.23.13.5.(2)PROPOSED CHANGE A-9.23.13.5.(2).)

[3] –)Interior or exterior wood-sheathed braced wall panels other than WSP-A in the uppermost storey shall extend to the roof framing and the top plates shall be connected to

[a] –)top chords of perpendicular or offset parallel trusses by using blocking panels or other methods of lateral load transfer designed by the roof truss manufacturer,
[b] –)perpendicular or offset parallel joists or rafters by using blocking of the same construction as the braced wall panel below, or
[c] –)rafters, joists or trusses by using methods of lateral load transfer designed in accordance with good engineering practice.
(See Note A-9.23.13.5.(3)‚ÄĒ2025 and (4)-2025.)

 

[4] –)The top plates of braced wall panels described in Sentence (3) shall be fastened in conformance with Table 9.23.3.4.

(See Note A-9.23.13.5.(3)-2025 and (4)-2025.)

 

[5] 3)Portions of the perimeter of a single open or enclosed space need not comply with Sentence (1), where

[a] a)the roof of the space projects not more than

[i] i)3.5 m from the face of the framing of the nearest parallel braced wall band, and
[ii] ii) the perpendicular plan dimension,

 

[b] b)that portion of the perimeter structure does not support a floor,

[c] c)the roof of the space is

[i] i)integral with the roof of the rest of the building with framing members not more than 400 mm o.c. where roof sheathing edges are not supported on blocking and not more than 600 mm o.c. where roof sheathing edges are supported on blocking securely fastened between framing members, or
[ii] ii)constructed with roof framing not more than 400 mm o.c. where roof sheathing edges are not supported on blocking and not more than 600 mm o.c. where roof sheathing edges are supported on blocking securely fastened between framing members, and fastened to the wall framing (see Table 9.23.3.4. and Article 9.23.9.1. for balloon framing), and

 

[d] d)the end-joists or end-rafters for the roof of the space are fastened to a 3-ply, 38 mm × 140 mm built-up column or a 5-ply, 38 mm × 89 mm built-up column that is integral with the wall framing.
(See Note A-9.23.13.5.(3)PROPOSED CHANGE A-9.23.13.5.(3).)

 

[6] 4)Walls in detached garages and in accessory buildings serving a single dwelling unit, and the front wall of attached garages serving a single dwelling unit need not comply with Sentence (1) where these walls do not support a floor.

[7] 5)Braced wall panels in the braced wall band at the front of an attached garage serving a single dwelling unit need not comply with Sentence (1), provided

[a] a)the maximum spacing between the front of the garage and the back wall of the garage does not exceed 7.6 m,
[b] b)there is not more than one floor above the garage,
[c] c)not less than 50% of the length of the back wall of the garage is constructed of braced wall panels, and
[d] d)not less than 25% of the length of the side walls is constructed of braced wall panels.

 

[9.23.13.6.] 9.23.13.6.Materials in Braced Wall Panels

[1] 1)Required braced wall panels shall be sheathed on the

[a] a)clad with panel-type cladding complying with Section 9.27. and Table 9.23.3.4.,
[b] b)sheathedexterior side with plywood, OSB, waferboard or diagonal lumber sheathing complying with Subsection 9.23.167. and Table 9.23.13.6., and fastened in accordance with Article9.23.3.5.Sentence 9.23.3.5.(3)Article 9.23.3.5., or and finish on the interior side with gypsum board sheathing complying with Subsection 9.29.5., or
[c] c)finished on the interior with a panel-type material in accordance with the requirements of Section 9.29. and Table 9.23.13.6.
[d] c)interior side or exterior side with gypsum board complying with Subsection 9.29.5. and fastened in accordance with Sentence 9.23.3.5.(3).(See Note A-9.23.13.6.(1)-2025)
[2] –)Except as permitted in Sentences (4) and (5), braced wall bands shall be constructed of braced wall panels of the same sheathing material.

[3] 6)At braced wall band spacing intervals of not more than 15 m, bBraced wall panels in basements and crawl spaces shall be sheathedconstructed with OSB, plywood, waferboard or diagonal lumber board. (See Note A-9.23.13.6.(5) and (6)PROPOSED CHANGE A-9.23.13.6.(5) and (6).)

[a] –)at braced wall band spacing intervals of not more than 15¬†m, and
[b] –)under all interior braced wall bands containing wood-sheathed braced wall panels.(See Note A-9.23.13.6.(3)-2020)
Table [9.23.13.6.] 9.23.13.6.
Minimum Thicknesses of Cladding, Sheathing or Interior Finish for Braced Wall Panels
Forming Part of Sentence [9.23.13.6.] 9.23.13.6.([1] 1)
Panel-Type Cladding, Sheathing or Interior Finish Minimum Thickness
Where Sa(0.2) ? 0.90 Where Sa(0.2) > 0.90
With supports 400 mm o.c. With supports 600 mm o.c. With supports 400 mm o.c. With supports 600 mm o.c.
Gypsum board interior finishPROPOSED CHANGE Table 9.23.13.6. Footnote (1) 12.7 mm 15.9 mm 12.7 mm 15.9 mm
Sheathing complying with CSA O325 W16 W24 W16 W24
OSB O-1 and O-2 grades 11 mm 12.5 mm 11 mm 12.5 mm
Waferboard R-1 grade 9.5 mm 12.5 mm n/a n/a
Plywood 11 mm 12.5 mm 11 mm 12.5 mm
Diagonal lumber 17 mm 17 mm n/a n/a

[4] 2)Except as provided in Sentence (3), required interior braced wall panels shall be

[a] a)sheathed or finished on both sides with a wood-based material, or
[b] b)finished on both sides with gypsum board.

 

[5] 3)Required interior braced wall panels of wood-based material may be sheathed on one side only, provided

[a] a)the sheathing material is plywood, OSB or waferboard, and
[b] b)the maximum spacing of fasteners along the edge is half of the maximum spacing shown in Table 9.23.3.5.-B.

 

[6] 4)For stacked braced wall bands, where the construction of any one braced wall panel is required to be of a wood-based material, a wood-based material shall be installed in all the required braced wall panels in that braced wall band.
[7] 5)Gypsum board interior finish shall not be considered as an acceptable sheathing material to provide the required bracing in exterior walls. (See Note A-9.23.13.6.(5) and (6)PROPOSED CHANGE A-9.23.13.6.(5) and (6).)

[8] –)Mixing of braced wall panel framing types in stacked braced wall bands is permitted where wood-sheathed braced wall panels are not above any braced wall bands with

[a] –)gypsum-sheathed braced wall panels or,
[b] –)diagonal lumber sheathed braced wall panels.

 

[9] –)Mixing of braced wall panel framing types along a braced wall band within the same storey is permitted

[a] –)where a WSP-A or WSP-B framing type is substituted for a GWB framing type and the total length of all of the braced wall panels is determined based on the GWB framing type, or
[b] –)provided the lengths of mixed braced wall panel framing types are based on accepted engineering principles.
(See Note A-9.23.13.6.(5)-2020

 

[9.23.13.7.]Braced Wall Panel Length

[1] –)Except as provided in Tables 9.23.13.7.-B-2025 and 9.23.13.7.-D-2025, all adjustment factors required for calculating the minimum total length of braced wall panels in this Article shall be taken as unity.

[2] –)The minimum total length of all braced wall panels in a braced wall band shall be the greater of Lw determined in Sentence (3) for the appropriate 1-in-50-year hourly wind pressure (HWP) and Ls determined in Sentence (4) for the appropriate seismic design parameter, Smax, where

[a] –)the 1-in-50 year hourly wind pressure (HWP) is not greater than 1.2 kPa, and
[b] –)the seismic design parameter, Smax for Site Class C, is not greater than 2.6.

 

[3] –)For the resistance of wind pressure, the minimum required total length of braced wall panels in each braced wall band, Lw, shall be determined by applying the adjustment factors provided in Table 9.23.13.7.-B-2025 to the wind-related unadjusted braced wall panel length Luw provided in Table 9.23.13.7.-A-2025 using the following equation:

Lw = LuwKexpKroofKWspacingKWnumberKgypKsheath ? BWPmin

where:

Luw
= total unadjusted braced wall panel length for wind from Table 9.23.13.7.-A-2025
Kexp
= wind exposure adjustment
= 1.0 for rough terrain: suburban, urban, and wooded areas
Kroof
= roof eave-to-ridge height adjustment
= 1.0 for 3m
KWspacing
= braced wall band spacing adjustment for wind per building plan direction
= 1.0 for 7.6 m braced wall band spacing
KWnumber
= number of braced wall bands adjustment for wind per building plan direction
= 1.0 for no intermediate braced wall bands between exterior walls
Kgyp
= interior gypsum board adjustment
= 1.0 for braced wall panels with interior gypsum board
Ksheath
= intermittent braced wall panels adjustment
= 1.0 for braced wall bands with continuously wood-sheathed exterior walls
BWPmin
= Minimum length of individual braced wall panels as per Table 9.23.13.5.-2025

 

(See Note A-9.23.13.7.(3)‚ÄĒ2025 for an alternative procedure to calculate the minimum braced wall panel length, Lw, directly.)

 

Table [9.23.13.7.-A]
Wind-related Minimum Total Unadjusted Braced Wall Panel LengthsPROPOSED CHANGE Table Footnote (1)PROPOSED CHANGE Table Footnote (2), Luw
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.7.] — ([3] –)
Unadjusted Braced Wall Panel Length, Luw, m
Diagonal lumber sheathed framing type (installed with gypsum board on opposite face)PROPOSED CHANGE Table Footnote (3) Gypsum-sheathed framing type (installed one face)PROPOSED CHANGE Table Footnote (3)PROPOSED CHANGE Table Footnote (4) Wood-sheathed framing type (installed with gypsum board on opposite face)PROPOSED CHANGE Table Footnote (3)
HWP Storey Location DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
? 0.3 0.65 3.29 1.91 1.42 1.14 1.14 0.60 0.52 0.48 0.43
1.33 6.75 3.92 2.91 2.35 2.35 1.24 1.08 0.98 0.88
2.02 10.21 5.93 4.40 3.57 3.57 1.87 1.63 1.49 1.34
0.3 < and ? 0.4 0.86 4.38 2.54 1.89 1.52 1.52 0.80 0.70 0.64 0.57
1.78 9.00 5.23 3.88 3.14 3.14 1.65 1.43 1.31 1.18
2.69 13.61 7.91 5.86 4.75 4.75 2.50 2.17 1.98 1.79
0.4 < and ? 0.5 1.08 5.84 3.18 2.36 1.90 1.90 1.00 0.87 0.79 0.72
2.22 11.25 6.54 4.85 3.92 3.92 2.06 1.79 1.63 1.47
3.37 17.01 9.88 7.33 5.94 5.94 3.12 2.72 2.48 2.23
0.5 < and ? 0.6 1.29 6.57 3.82 2.83 2.29 2.29 1.20 1.05 0.95 0.86
2.67 13.50 7.84 5.82 4.71 4.71 2.47 2.15 1.96 1.77
4.04 20.42 11.86 8.79 7.13 7.13 3.75 3.26 2.97 2.68
0.6 < and ? 0.9 1.94 9.86 5.73 4.25 3.43 3.43 1.80 1.57 1.43 1.29
4.00 20.25 11.76 8.72 7.06 7.06 3.71 3.23 2.94 2.65
6.06 30.62 17.79 13.19 10.70 10.70 5.62 4.89 4.46 4.02
0.9 < and ? 1.2 2.59 13.14 7.63 5.66 4.57 4.57 2.40 2.09 1.91 1.72
5.33 27.00 15.68 11.63 9.41 9.41 4.95 4.30 3.92 3.54
8.08 40.83 23.72 17.59 14.26 14.26 7.50 6.52 5.94 5.36
Table [9.23.13.7.-B]
Wind-related Adjustment Factors for Braced Wall Panel Lengths
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.7.] — ([3] –)
Factor Adjustment based on Storey/Supporting Condition Adjustment Factor
KexpPROPOSED CHANGE Table Footnote (1) Wind exposure: use the highest applicable factor to all storeys in both directions All storeys Rough terrain 1.00
1‚Äďstorey building Open terrain 1.29
2‚Äďstorey building 1.40
3‚Äďstorey building 1.48
KroofPROPOSED CHANGE Table Footnote (2) Roof eave-to-ridge height: apply separately to each storey Supporting Roof only ? 1.5 m 0.52
3.0 m 1.00
4.5 m 1.58
6.0 m 1.99
Supporting Roof + 1 floor ? 1.5 m 0.79
3.0 m 1.00
4.5 m 1.26
6.0 m 1.47
Supporting Roof + 2 floors ? 1.5 m 0.87
3.0 m 1.00
4.5 m 1.16
6.0 m 1.31
KWspacing(2)PROPOSED CHANGE Table Footnote (3) Braced wall band spacing: apply to all braced wall panels per building plan direction Any storey 3.8 m 0.51
7.6 m 1.00
10.6 m 1.35
15 mPROPOSED CHANGE Table Footnote (4) 1.86
KWnumber Number of parallel braced wall bands: apply to all braced wall panels per building plan direction Any storey 2 1.00
3 1.28
4 1.38
? 5 1.43
Kgyp Interior gypsum board: apply where gypsum omitted from interior face of braced wall panels Any storey Include 1.00
Omitted, blocked wall 1.20
Omitted, unblocked wall 1.40
Ksheath Braced wall panel continuity within braced wall band Any storey Continuously sheathed 1.00
Intermittently sheathed 1.15

[4] –)For the resistance of seismic forces, the minimum required total length of braced wall panels in each braced wall band, Ls, shall be determined by applying the adjustment factors provided in Table 9.23.13.7.-D-2025 to the seismic-related unadjusted braced wall panel length, Lus, provided in Table 9.23.13.7.-C-2025 using the following equation:

Ls = LusKweightKsnowKSspacingKSnumberKgypKsheath? BWPmin

where:

Lus
= total unadjusted braced wall panel length for seismic bracing from Table 9.23.13.7.-C-2025
Kweight
= weight of construction and cladding adjustment, for seismic
= 1.0 for normal weight construction – See Sentence 9.23.13.2.(3)
Ksnow
= roof snow load adjustment, for seismic
= 1.0 for 2 kPa roof snow load and below (as calculated in accordance with Article 9.4.2.2.)
KSspacing
= braced wall band spacing adjustment for seismic per building plan direction ‚Äď See Sentence 9.23.13.7.(5)-2025
= 1.0 for 7.6 m braced wall band spacing
KSnumber
= number of braced wall bands adjustment for seismic per building plan direction
= 1.0 for no intermediate braced wall bands between exterior walls
Kgyp
= interior gypsum board adjustment
= 1.0 for braced wall panels with interior gypsum board
Ksheath
= intermittent braced wall panels adjustment
= 1.0 for continuously wood-sheathed braced wall bands
BWPmin
= Minimum length of individual braced wall panels as per Table 9.23.13.5.

 

(See Note A-9.23.13.7.(4)-2025 for an alternative procedure to calculate the adjusted braced wall panel length directly.)

 

Table [9.23.13.7.-C]
Seismic-related Minimum Total Unadjusted Braced Wall Panel Lengths, Lus
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.7.] — ([4] –)
Smax Storey Location Building dimension parallel to Braced Wall Panel, Lwl, m Unadjusted Braced Wall Panel LengthsPROPOSED CHANGE Table Footnote (1)PROPOSED CHANGE Table Footnote (2), Lus, m
Diagonal lumber sheathed framing type Gypsum-sheathed framing type (installed one face)PROPOSED CHANGE Table Footnote (3)PROPOSED CHANGE Table Footnote (4) Wood-sheathed framing type (installed with gypsum board on opposite face)PROPOSED CHANGE Table Footnote (3)
DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
? 0.2 3.1 0.06 0.47 0.27 0.20 0.17 0.11 0.06 0.05 0.05 0.04
6.1 0.11 0.81 0.47 0.35 0.28 0.19 0.10 0.09 0.08 0.07
9.1 0.15 1.15 0.67 0.50 0.40 0.27 0.14 0.12 0.11 0.10
12.2 0.20 1.5 0.87 0.65 0.53 0.35 0.18 0.16 0.15 0.13
15.2 0.24 1.81 1.05 0.78 0.64 0.43 0.23 0.20 0.18 0.16
18.3 0.29 2.20 1.28 0.95 0.77 0.51 0.27 0.23 0.21 0.19
3.1 0.15 1.10 0.65 0.48 0.39 0.26 0.14 0.12 0.11 0.10
6.1 0.24 1.84 1.07 0.79 0.65 0.43 0.23 0.20 0.18 0.16
9.1 0.34 2.57 1.49 1.11 0.90 0.60 0.32 0.27 0.25 0.23
12.2 0.44 3.32 1.93 1.43 1.17 0.78 0.41 0.36 0.32 0.29
15.2 0.54 3.99 2.31 1.72 1.40 0.95 0.50 0.43 0.39 0.36
18.3 0.64 4.80 2.79 2.07 1.68 1.12 0.59 0.51 0.47 0.42
3.1 0.23 1.76 1.02 0.76 0.62 0.41 0.22 0.19 0.17 0.15
6.1 0.38 2.87 1.67 1.24 1.01 0.67 0.35 0.31 0.28 0.25
9.1 0.53 3.99 1.49 1.72 1.40 0.93 0.49 0.43 0.39 0.35
12.2 0.68 5.14 2.99 2.21 1.80 1.20 0.63 0.55 0.50 0.45
15.2 0.83 6.16 3.58 2.65 2.16 1.46 0.77 0.67 0.61 0.55
18.3 0.98 7.41 4.30 3.19 2.60 1.73 0.91 0.79 0.72 0.65
0.2 < and ? 0.4 3.1 0.13 0.94 0.55 0.41 0.33 0.22 0.12 0.10 0.09 0.08
6.1 0.22 1.63 0.94 0.70 0.57 0.38 0.20 0.17 0.16 0.14
9.1 0.31 2.31 1.34 0.99 0.81 0.54 0.28 0.25 0.22 0.20
12.2 0.40 3.01 1.75 1.30 1.05 0.70 0.37 0.32 0.29 0.26
15.2 0.49 3.63 2.11 1.56 1.27 0.86 0.45 0.39 0.36 0.32
18.3 0.58 4.39 2.55 1.89 1.54 1.03 0.54 0.47 0.43 0.39
3.1 0.30 2.23 1.30 0.96 0.78 0.52 0.27 0.24 0.22 0.20
6.1 0.49 3.69 2.14 1.59 1.29 0.86 0.45 0.39 0.36 0.32
9.1 0.68 5.14 2.99 2.21 1.80 1.20 0.63 0.55 0.50 0.45
12.2 0.88 6.65 3.86 2.86 2.33 1.55 0.82 0.71 0.65 0.58
15.2 1.07 7.97 4.63 3.43 2.79 1.89 1.00 0.87 0.79 0.71
18.3 1.27 9.61 5.58 4.14 3.37 2.25 1.18 1.03 0.94 0.84
3.1 0.47 DRPROPOSED CHANGE Table Footnote (5)

(1.12)

 

2.04 1.51 1.23 0.82 0.43 0.38 0.34 0.31
6.1 0.76 5.50 3.34 2.48 2.01 1.34 0.71 0.61 0.56 0.50
9.1 1.06 7.98 4.63 3.44 2.80 1.86 0.98 0.85 0.78 0.70
12.2 1.36 10.29 5.97 4.43 3.61 2.40 1.26 1.10 1.00 0.90
15.2 1.66 12.31 7.15 5.30 4.32 2.93 1.54 1.34 1.22 1.10
18.3 1.96 14.82 8.61 6.38 5.20 3.46 1.82 1.58 1.44 1.30
? 0.6 3.1 0.19 1.42 0.82 0.61 0.50 0.33 0.17 0.15 0.14 0.12
6.1 0.32 2.44 1.42 1.05 0.85 0.57 0.30 0.26 0.24 0.21
9.1 0.46 3.46 2.01 1.49 1.21 0.81 0.42 0.37 0.34 0.30
12.2 0.60 4.51 2.62 1.94 1.58 1.05 0.55 0.48 0.44 0.40
15.2 0.73 5.44 3.16 2.34 1.91 1.29 0.68 0.59 0.54 0.49
18.3 0.87 6.59 3.83 2.84 2.31 1.54 0.81 0.70 0.64 0.58
3.1 0.44 DR(5)

(1.67)

 

1.94 1.44 1.17 0.78 0.41 0.36 0.33 0.29
6.1 0.73 5.53 3.21 2.38 1.94 1.29 0.68 0.59 0.54 0.49
9.1 1.02 7.71 4.48 3.32 2.70 1.80 0.95 0.82 0.75 0.68
12.2 1.32 9.97 5.79 4.29 3.50 2.33 1.23 1.07 0.97 0.88
15.2 1.61 11.96 6.94 5.15 4.19 2.84 1.49 1.30 1.18 1.07
18.3 1.91 14.41 8.37 6.21 5.05 3.37 1.77 1.54 1.40 1.27
3.1 0.70 DR(5)

(2.64)

 

3.06 2.27 1.85 1.23 0.65 0.56 0.51 0.46
6.1 1.14 DR(5)

(4.31)

 

5.01 3.71 3.02 2.01 1.06 0.92 0.84 0.76
9.1 1.59 DR(5)

(5.99)

 

6.95 5.15 4.20 2.80 1.47 1.28 1.17 1.05
12.2 2.04 DR(5)

(7.72)

 

8.96 6.64 5.41 3.61 1.90 1.65 1.50 1.35
15.2 2.49 DR(5)

(9.24)

 

10.73 7.96 6.48 4.39 2.31 2.01 1.83 1.65
18.3 2.95 DR(5)

(11.12)

 

12.91 9.58 7.80 5.20 2.73 2.38 2.17 1.95
0.6 < and ? 0.8 3.1 0.25 1.89 1.10 0.81 0.66 0.44 0.23 0.20 0.18 0.17
6.1 0.43 3.25 1.89 1.40 1.14 0.76 0.40 0.35 0.32 0.29
9.1 0.61 4.61 2.68 1.99 1.62 1.08 0.57 0.49 0.45 0.40
12.2 0.80 6.02 3.49 2.59 2.11 1.41 0.74 0.64 0.59 0.53
15.2 0.98 7.25 4.21 3.12 2.54 1.72 0.91 0.79 0.72 0.65
18.3 1.16 8.78 5.10 3.78 3.08 2.05 1.08 0.94 0.86 0.77
3.1 0.59 DR(5)

(2.23)

 

2.59 1.92 1.56 1.04 0.55 0.48 0.43 0.39
6.1 0.98 DR(5)

(3.69)

 

4.28 3.18 2.58 1.72 0.91 0.79 0.72 0.65
9.1 1.36 DR(5)

(5.14)

 

5.97 4.43 3.61 2.40 1.26 1.10 1.00 0.90
12.2 1.76 DR(5)

(6.65)

 

7.72 5.73 4.66 3.11 1.63 1.42 1.29 1.17
15.2 2.15 DR(5)

(7.97)

 

9.26 6.87 5.59 3.79 1.99 1.73 1.58 1.42
18.3 2.55 DR(5)

(9.61)

 

11.16 8.28 6.74 4.49 2.36 2.05 1.87 1.69
3.1 0.93 DR(5) DR(5)

(2.04)

 

3.03 2.46 1.64 0.86 0.75 0.68 0.62
6.1 1.52 DR(5)

(5.75)

 

DR(5)

(3.34)

 

4.95 4.03 2.69 1.41 1.23 1.12 1.01
9.1 2.11 DR(5)

(7.98)

 

DR(5)

(4.64)

 

6.87 5.59 3.73 1.96 1.71 1.55 1.40
12.2 2.72 DR(5)

(10.29)

 

11.95 8.86 7.21 4.81 2.53 2.20 2.00 1.81
15.2 3.32 DR(5)

(12.32)

 

14.30 10.61 8.63 5.85 3.08 2.68 2.44 2.20
18.3 3.93 DR(5)

(14.83)

 

17.22 12.77 10.39 6.93 3.64 3.17 2.89 2.60
0.8 < and ? 1.2 3.1 0.38 2.83 1.65 1.22 0.99 0.66 0.35 0.30 0.28 0.25
6.1 0.65 4.88 2.83 2.10 1.71 1.14 0.60 0.52 0.47 0.43
9.1 0.92 6.92 4.02 2.98 2.42 1.62 0.85 0.74 0.67 0.61
12.2 1.20 9.03 5.24 3.89 3.16 2.11 1.11 0.96 0.88 0.79
15.2 1.47 10.88 6.32 4.69 3.81 2.59 1.36 1.18 1.08 0.97
18.3 1.75 13.18 7.65 5.67 4.62 3.08 1.62 1.41 1.28 1.16
3.1 0.89 DR(5) DR(5)

(1.95)

 

2.88 2.35 1.56 0.82 0.71 0.65 0.59
6.1 1.46 DR(5)

(5.53)

 

DR(5)

(3.21)

 

4.76 3.88 2.58 1.36 1.18 1.08 0.97
9.1 2.04 DR(5)

(7.72)

 

8.96 6.64 5.41 3.61 1.90 1.65 1.50 1.35
12.2 2.64 DR(5)

(9.97)

 

11.58 8.59 6.99 4.66 2.45 2.13 1.94 1.75
15.2 3.22 DR(5)

(11.96)

 

13.89 10.30 8.38 5.68 2.99 2.60 2.37 2.13
18.3 3.82 DR(5)

(14.41)

 

16.74 12.41 10.11 6.74 3.54 3.08 2.81 2.53
3.1 1.40 DR(5) DR(5)

(3.06)

 

DR(5)

(2.27)

 

DR(5)

(1.85)

 

2.46 1.30 1.13 1.03 0.93
6.1 2.28 DR(5) DR(5)

(5.01)

 

DR(5)

(3.72)

 

6.04 4.03 2.12 1.84 1.68 1.51
9.1 3.17 DR(5) DR(5)

(6.95)

 

DR(5)

(5.16)

 

8.39 5.59 2.94 2.56 2.33 2.10
12.2 4.09 DR(5) DR(5)

(8.96)

 

DR(5)

(6.65)

 

10.82 7.21 3.79 3.30 3.01 2.71
15.2 4.97 DR(5) DR(5)

(10.73)

 

DR(5)

(7.96)

 

12.95 8.78 4.61 4.01 3.66 3.30
18.3 5.89 DR(5) DR(5)

(12.92)

 

DR(5)

(9.58)

 

15.59 10.39 5.46 4.75 4.33 3.90
1.2 < and ? 1.6 3.1 0.50 DR(5)

(1.89)

 

2.19 1.63 1.32 0.88 0.46 0.40 0.37 0.33
6.1 0.86 DR(5)

(3.25)

 

3.78 2.80 2.28 1.52 0.80 0.69 0.63 0.57
9.1 1.22 DR(5)

(4.61)

 

5.36 3.67 3.23 2.16 1.13 0.99 0.90 0.81
12.2 1.59 12.03 6.99 5.18 4.22 2.81 1.48 1.29 1.17 1.06
15.2 1.95 14.51 8.43 6.25 5.09 3.45 1.81 1.58 1.44 1.30
18.3 2.33 17.57 10.20 7.57 6.16 4.11 2.16 1.88 1.71 1.54
3.1 1.18 DR(5) DR(5)

(2.59)

 

DR(5)

(1.92)

 

3.13 2.08 1.10 0.95 0.87 0.78
6.1 1.95 DR(5) DR(5)

(4.28)

 

DR(5)

(3.18)

 

5.17 3.45 1.81 1.58 1.44 1.29
9.1 2.72 DR(5) DR(5)

(5.98)

 

8.86 7.21 4.81 2.53 2.20 2.00 1.81
12.2 3.52 DR(5) DR(5)

(7.72)

 

11.45 9.32 6.21 3.27 2.84 2.59 2.33
15.2 4.29 DR(5) DR(5)

(9.26)

 

13.73 11.18 7.58 3.98 3.46 3.16 2.85
18.3 5.09 DR(5) DR(5)

(11.16)

 

16.55 13.47 8.98 4.72 4.11 3.74 3.37
3.1 1.86 DR(5) DR(5) DR(5)

(3.03)

 

DR(5)

(2.47)

 

DR(5) 1.73 1.50 1.37 1.23
6.1 3.05 DR(5) DR(5) DR(5)

(4.95)

 

DR(5)

(4.03)

 

5.37 2.82 2.46 2.24 2.02
9.1 4.23 DR(5) DR(5) DR(5)

(6.87)

 

DR(5)

(5.60)

 

7.46 3.92 3.41 3.11 2.80
12.2 5.45 DR(5) DR(5)

(11.95)

 

DR(5)

(8.86)

 

DR(5)

(7.21)

 

9.62 5.06 4.40 4.01 3.61
15.2 6.63 DR(5) DR(5)

(14.31)

 

DR(5)

(10.61)

 

DR(5)

(8.64)

 

11.70 6.15 5.35 4.88 4.40
18.3 7.85 DR(5) DR(5)

(17.22)

 

DR(5)

(12.77)

 

DR(5)

(10.40)

 

13.86 7.29 6.34 5.78 5.21
1.6 < and ? 2.0 3.1 0.63 DR(5)

(2.36)

 

2.74 2.03 1.66 1.10 0.58 0.50 0.46 0.41
6.1 1.08 DR(5)

(4.07)

 

4.72 3.50 2.85 1.90 1.00 0.87 0.79 0.71
9.1 1.53 DR(5)

(5.77)

 

6.70 4.96 4.04 2.69 1.42 1.23 1.12 1.01
12.2 1.99 DR(5)

(7.52)

 

8.74 6.48 5.27 3.52 1.85 1.61 1.47 1.32
15.2 2.44 DR(5)

(9.07)

 

10.53 7.81 6.36 4.31 2.27 1.97 1.80 1.62
18.3 2.91 DR(5)

(10.98)

 

12.75 9.46 7.70 5.13 2.70 2.35 2.14 1.93
3.1 1.48 DR(5) DR(5) DR(5)

(2.40)

 

DR(5)

(1.96)

 

2.61 1.37 1.19 1.09 0.98
6.1 2.44 DR(5) DR(5)

(5.35)

 

DR(5)

(3.97)

 

DR(5)

(3.23)

 

4.31 2.26 1.97 1.80 1.62
9.1 3.41 DR(5) DR(5)

(7.47)

 

DR(5)

(5.54)

 

DR(5)

(4.51)

 

6.01 3.16 2.75 2.50 2.26
12.2 4.40 DR(5) DR(5)

(9.65)

 

DR(5)

(7.16)

 

11.65 7.77 4.08 3.55 3.24 2.92
15.2 5.37 DR(5) DR(5)

(11.08)

 

DR(5)

(8.58)

 

13.97 9.47 4.98 4.33 3.95 3.56
18.3 6.36 DR(5) DR(5)

(13.95)

 

DR(5)

(10.35)

 

16.84 11.23 5.90 5.13 4.68 4.22
3.1 2.33 DR(5) DR(5) DR(5) DR(5)

(3.08)

 

DR(5) 2.16 1.88 1.71 1.54
6.1 3.81 DR(5) DR(5) DR(5) DR(5)

(5.04)

 

DR(5) 3.53 3.07 2.80 2.52
9.1 5.28 DR(5) DR(5) DR(5)

(8.59)

 

DR(5)

(7.00)

 

DR(5) 4.90 4.26 3.89 3.50
12.2 6.81 DR(5) DR(5) DR(5)

(11.08)

 

DR(5)

(9.02)

 

12.02 6.32 5.50 5.01 4.51
15.2 8.29 DR(5) DR(5) DR(5)

(13.26)

 

DR(5)

(11.00)

 

14.63 7.69 6.69 6.10 5.49
18.3 9.82 DR(5) DR(5) DR(5)

(15.96)

 

DR(5)

(13.00)

 

17.32 9.11 7.92 7.22 6.51
2.0 < and ? 2.6 3.1 0.81 DR(5)

(3.07)

 

DR(5)

(1.79)

 

2.65 2.15 1.44 0.75 0.66 0.60 0.54
6.1 1.40 DR(5)

(5.28)

 

DR(5)

(3.07)

 

4.55 3.70 2.47 1.30 1.13 1.03 0.93
9.1 1.99 DR(5)

(7.50)

 

8.70 6.45 5.25 3.50 1.84 1.60 1.46 1.32
12.2 2.59 DR(5)

(9.78)

 

11.36 8.42 6.86 4.57 2.40 2.09 1.90 1.72
15.2 3.18 DR(5)

(11.79)

 

13.69 10.15 8.27 5.60 2.95 2.56 2.34 2.11
18.3 3.78 DR(5)

(14.28)

 

16.58 12.30 10.01 6.67 3.51 3.05 2.78 2.51
3.1 1.92 DR(5) DR(5) DR(5) DR(5)

(2.54)

 

DR(5) 1.78 1.55 1.41 1.27
6.1 3.17 DR(5) DR(5) DR(5)

(5.16)

 

DR(5)

(4.20)

 

5.60 2.94 2.56 2.33 2.10
9.1 4.43 DR(5) DR(5) DR(5)

(7.20)

 

DR(5)

(5.86)

 

7.81 4.11 3.57 3.26 2.93
12.2 5.72 DR(5) DR(5) DR(5)

(9.31)

 

DR(5)

(7.58)

 

10.10 5.31 4.62 4.21 3.79
15.2 6.98 DR(5) DR(5)

(15.05)

 

DR(5)

(11.16)

 

DR(5)

(9.58)

 

12.31 6.47 5.63 5.13 4.62
18.3 8.27 DR(5) DR(5)

(18.14)

 

DR(5)

(13.45)

 

DR(5)

(10.95)

 

14.60 7.67 6.67 6.08 5.48
3.1 3.03 DR(5) DR(5) DR(5) DR(5) DR(5) 2.81 2.44 2.23 2.01
6.1 4.95 DR(5) DR(5) DR(5) DR(5) DR(5) 4.59 3.99 3.64 3.28
9.1 6.87 DR(5) DR(5) DR(5) DR(5)

(9.09)

 

DR(5) 6.37 5.54 5.05 4.55
12.2 8.86 DR(5) DR(5) DR(5) DR(5)

(11.72)

 

DR(5) 8.22 7.14 6.51 5.87
15.2 10.78 DR(5) DR(5) DR(5) DR(5)

(14.03)

 

DR(5) 10.00 8.69 7.92 7.14
18.3 12.76 DR(5) DR(5) DR(5) DR(5)

(16.89)

 

DR(5) 11.84 10.30 9.38 8.46
Table [9.23.13.7.-D]
Seismic-related Adjustment Factors Braced Wall Panel Lengths
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.7.] — ([4] –)
Factor Adjustment based on Storey/Supporting Condition Adjustment Factor
KweightPROPOSED CHANGE Table Footnote (1) Normal constructionPROPOSED CHANGE Table Footnote (2) Any storey Any building depth 1.0
Heavy constructionPROPOSED CHANGE Table Footnote (2) Building depth
Construction weightPROPOSED CHANGE Table Footnote (2)
Apply factor corresponding to the building depth in the direction of the braced wall bandApply separately to each storey

Supporting roof only
? 3.1 m 1.72
6.1 m 1.54
9.1 m 1.46
12.2 m 1.42
15.2 m 1.39
? 18.3 m 1.38

Supporting roof + 1 floor
? 3.1 m 1.92
6.1 m 1.71
9.1 m 1.62
12.2 m 1.57
15.2 m 1.54
? 18.3 m 1.51

Supporting roof + 2 floorsPROPOSED CHANGE Table Footnote (3)
? 3.1 m 1.97
6.1 m 1.76
9.1 m 1.67
12.2 m 1.61
15.2 m 1.58
? 18.3 m 1.56
Masonry veneerPROPOSED CHANGE Table Footnote (2) Building depth One face Both faces
Masonry veneer cladding perpendicular to braced wall band, fully cladPROPOSED CHANGE Table Footnote (4): Apply factor corresponding to building depth in the direction of the braced wall band for one or two building face(s)

Supporting roof only
? 3.1 m 1.54 2.13
6.1 m 1.30 1.64
9.1 m 1.21 1.45
12.2 m 1.15 1.34
15.2 m 1.12 1.28
? 18.3 m 1.10 1.23

Supporting roof + 1 floor
? 3.1 m 1.69 2.43
6.1 m 1.40 1.85
9.1 m 1.28 1.60
12.2 m 1.21 1.46
15.2 m 1.17 1.38
? 18.3 m 1.14 1.31

Supporting roof + 2 floorsPROPOSED CHANGE Table Footnote (3)
? 3.1 m 1.73 2.51
6.1 m 1.43 1.91
9.1 m 1.30 1.65
12.2 m 1.22 1.50
15.2 m 1.18 1.41
? 18.3 m 1.15 1.33
Masonry veneer cladding perpendicular to braced wall band, partially cladPROPOSED CHANGE Table Footnote (4):
Apply factor corresponding to building depth in the direction of the braced wall band for one or two building face(s)

Supporting roof only
? 3.1 m 1.23 1.52
6.1 m 1.13 1.29
9.1 m 1.08 1.20
12.2 m 1.06 1.15
15.2 m 1.04 1.12
? 18.3 m 1.03 1.09

Supporting roof + 1 floor
? 3.1 m 1.30 1.66
6.1 m 1.17 1.39
9.1 m 1.11 1.27
12.2 m 1.08 1.20
15.2 m 1.06 1.16
? 18.3 m 1.05 1.13

Supporting roof + 2 floorsPROPOSED CHANGE Table Footnote (3)
? 3.1 m 1.31 1.70
6.1 m 1.18 1.42
9.1 m 1.12 1.29
12.2 m 1.08 1.21
15.2 m 1.07 1.17
? 18.3 m 1.05 1.14
Masonry veneer cladding perpendicular to the braced wall band, 1 storey height, with openings:
Apply factor corresponding to building depth Lwl in the direction of the braced wall band for one or two building face(s)

Supporting roof + 1 floor
? 3.1 m 1.23 1.48
6.1 m 1.13 1.28
9.1 m 1.09 1.20
12.2 m 1.07 1.15
15.2 m 1.06 1.13
? 18.3 m 1.05 1.10

Supporting roof + 2 floorsPROPOSED CHANGE Table Footnote (3)
? 3.1 m 1.15 1.30
6.1 m 1.09 1.18
9.1 m 1.06 1.13
12.2 m 1.04 1.10
15.2 m 1.04 1.08
? 18.3 m 1.03 1.07
Masonry veneer cladding perpendicular to the braced wall band, 2 storey height, fully clad:
Apply factor corresponding to building depth Lwl in the direction of the braced wall band for one or two building face(s)

Supporting roof + 1 floor
? 3.1 m 1.23 1.48
6.1 m 1.13 1.28
9.1 m 1.09 1.20
12.2 m 1.07 1.15
15.2 m 1.06 1.13
? 18.3 m 1.05 1.10

Supporting roof + 2 floorsPROPOSED CHANGE Table Footnote (3)
? 3.1 m 1.44 1.91
6.1 m 1.26 1.55
9.1 m 1.18 1.39
12.2 m 1.13 1.30
15.2 m 1.11 1.24
? 18.3 m 1.09 1.20
Stone veneerPROPOSED CHANGE Table Footnote (2) Building depth One face Both faces
Stone veneer cladding perpendicular to braced wall band, fully cladPROPOSED CHANGE Table Footnote (4): Apply factor corresponding to building depth in the direction of the braced wall band for one or two building face(s)

Supporting roof only
? 3.1 m 1.95 2.95
6.1 m 1.54 2.13
9.1 m 1.38 1.79
12.2 m 1.28 1.60
15.2 m 1.23 1.49
? 18.3 m 1.19 1.40

Supporting roof + 1 floor
? 3.1 m 2.21 3.48
6.1 m 1.72 2.50
9.1 m 1.51 2.06
12.2 m 1.38 1.82
15.2 m 1.31 1.66
? 18.3 m 1.26 1.55

Supporting roof + 2 floors
? 3.1 m 2.28 3.63
6.1 m 1.77 2.60
9.1 m 1.55 2.14
12.2 m 1.41 1.88
15.2 m 1.33 1.72
? 18.3 m 1.28 1.60
Stone veneer cladding perpendicular to braced wall band, partially cladPROPOSED CHANGE Table Footnote (4):
Apply factor corresponding to building depth in the direction of the braced wall band for one or two building face(s)

Supporting roof only
? 3.1 m 1.44 1.94
6.1 m 1.25 1.54
9.1 m 1.17 1.37
12.2 m 1.13 1.28
15.2 m 1.10 1.23
? 18.3 m 1.08 1.18

Supporting roof + 1 floor
? 3.1 m 1.56 2.19
6.1 m 1.33 1.71
9.1 m 1.22 1.50
12.2 m 1.17 1.38
15.2 m 1.13 1.31
? 18.3 m 1.11 1.25

Supporting roof + 2 floors
? 3.1 m 1.59 2.26
6.1 m 1.35 1.76
9.1 m 1.24 1.53
12.2 m 1.18 1.41
15.2 m 1.14 1.33
? 18.3 m 1.12 1.27
Stone veneer cladding perpendicular to the braced wall band, 1 storey height, with openings:
Apply factor corresponding to depth Lwl in the direction of the braced wall band for one or two building face(s).

Supporting roof + 1 floor
? 3.1 m 1.19 1.40
6.1 m 1.11 1.24
9.1 m 1.07 1.17
12.2 m 1.06 1.13
15.2 m 1.04 1.10
? 18.3 m 1.04 1.08

Supporting roof + 2 floors
? 3.1 m 1.12 1.25
6.1 m 1.07 1.15
9.1 m 1.05 1.11
12.2 m 1.04 1.08
15.2 m 1.03 1.07
? 18.3 m 1.02 1.05
Stone veneer cladding perpendicular to the braced wall band, 2 storey height, with openings:
Apply factor corresponding to depth Lwl in the direction of the braced wall band for one or two building face(s).

Supporting roof + 1 floor
? 3.1 m 1.19 1.40
6.1 m 1.11 1.24
9.1 m 1.07 1.17
12.2 m 1.06 1.13
15.2 m 1.04 1.10
? 18.3 m 1.04 1.08

Supporting roof + 2 floors
? 3.1 m 1.36 1.76
6.1 m 1.21 1.45
9.1 m 1.14 1.32
12.2 m 1.11 1.24
15.2 m 1.09 1.20
? 18.3 m 1.07 1.16
Stone veneer cladding perpendicular to the braced wall band, 1 storey height, fully clad:
Apply factor corresponding to depth Lwl in the direction of the braced wall band for one or two building face(s).

Supporting roof + 1 floor
? 3.1 m 1.40 1.83
6.1 m 1.24 1.50
9.1 m 1.17 1.35
12.2 m 1.13 1.27
15.2 m 1.10 1.22
? 18.3 m 1.09 1.18

Supporting roof + 2 floors
? 3.1 m 1.26 1.53
6.1 m 1.15 1.32
9.1 m 1.11 1.23
12.2 m 1.08 1.18
15.2 m 1.07 1.14
? 18.3 m 1.06 1.12
Stone veneer cladding perpendicular to the braced wall band, 2 storey height, fully clad:
Apply factor corresponding to depth Lwl in the direction of the braced wall band for one or two building face(s).

Supporting roof + 1 floor
? 3.1 m 1.40 1.83
6.1 m 1.24 1.50
9.1 m 1.17 1.35
12.2 m 1.13 1.27
15.2 m 1.10 1.22
? 18.3 m 1.09 1.18

Supporting roof + 2 floors
? 3.1 m 1.77 2.58
6.1 m 1.46 1.96
9.1 m 1.33 1.68
12.2 m 1.25 1.53
15.2 m 1.20 1.43
? 18.3 m 1.17 1.36
Ksnow(1) Roof snow load Supporting roof only ? 2kPa 1.00
3 kPa 1.20
4 kPa 1.40
5 kPa 1.60
6 kPa 1.80
Supporting roof + 1 floor ? 2kPa 1.00
3 kPa 1.10
4 kPa 1.20
5 kPa 1.30
6 kPa 1.40
Supporting roof + 2 floors ? 2kPa 1.00
3 kPa 1.06
4 kPa 1.10
5 kPa 1.20
6 kPa 1.24
KSspacing(1) Braced wall band spacing: apply to all braced wall panels per building plan direction Any storey 3.8 m 0.60
7.6 m 1.00
10.6 m 1.35
15 mPROPOSED CHANGE Table Footnote (5) 1.90
KSnumber Number of parallel braced wall bands: apply to all braced wall panels per building plan direction Any storey 2 1.00
3 1.33
4 1.50
? 5 1.60
Kgyp Interior gypsum board: apply where gypsum omitted from interior face of braced wall panels Any storey Included 1.00
Omitted, blocked wall 1.20
Omitted, unblocked 1.40
Ksheath Braced wall panel continuity within braced wall band Any storey Continuously wood-sheathed 1.00
Intermittently sheathed 1.15
[5] –)Where 3 or more parallel braced wall bands exist, and the braced wall bands are not evenly spaced, an average braced wall band spacing is permitted to be used for the determination of KWspacing or KSspacing, except that no single braced wall band spacing may exceed 10.6 m, except as permitted in Sentence 9.23.13.6.(3)-2025.
[6] –)Where braced wall panels constructed with gypsum-sheathed framing types have gypsum board installed on both sides, the braced wall panel lengths determined in Sentences 9.23.13.7.(3) and (4)-2025 are permitted to be reduced by 50%.

[9.23.13.8.]Foundation Cripple Walls

(See Note A-9.23.13.8.)

[1] –)Except as provided in Sentences (2) and (3), foundation cripple walls supporting braced wall panels shall be

[a] –)considered as an additional storey, or
[b] –)designed in accordance with Part 4.

 

[2] –)Where the seismic design parameter, Smax, is less than or equal to 0.60, foundation cripple walls need not comply with Sentence (1), provided they

[a] –)are not more than 1.2¬†m in height,
[b] –)are not more than 6¬†m in length.

[c] –)are either

[i] –)framed with solid blocking, or
[ii] –)of the same construction as the braced wall panels of the storey above but sheathed with wood sheathing regardless of the construction, where the length of the cripple wall bracing is equal to the length of the braced wall panels multiplied by an adjustment factor of 1.2, in addition to any adjustments required by Sentences 9.23.13.7.(1)-2025 and (2)-2025, and

 

[d] –)do not support heavy weight construction or masonry or stone veneer.
(See Note A-9.23.13.8.(2).-2025)

 

[3] –)Where the seismic design parameter, Smax, is greater than 0.60, foundation cripple walls need not comply with Sentence (1), provided they

[a] –)comply with Clauses (2)(c) and (d),
[b] –)are not more than 350¬†mm in height, and
[c] –)are not more than 5¬†m in length.
(See Note A-9.23.13.8.(3).-2025)

 

[4] –)Where interior finish, such as gypsum board, is omitted from the interior side of the cripple wall referred to in Sentence (2) or (3), the adjustment factor described in Sentence 9.23.13.7.(1)-2025 shall be applied to the length of the cripple wall bracing.

[9.23.13.9.]Cripple Walls in Stepped Foundations

[1] –)Cripple walls in stepped foundations need not be braced in accordance with Sentences 9.23.13.8.(2)-2025 to (4)-2025, provided

[a] –)the lowest floor framing rests directly on a sill plate anchored to a foundation not less than 2.4 m in length within a braced wall band not more than 7.6¬†m in length,
[b] –)the top plate of the cripple wall extends not less than 1.2¬†m along the foundation, and
[c] –)anchor bolts are located not more than 300¬†mm and 900¬†mm from the step in the foundation.
(See Note A-9.23.13.9.(1).-2025)

 

[9.23.13.10.] 9.23.13.7.Additional System Considerations

[1] –)This Article applies in locations where the seismic design parameter, Smax, is not greater than 1.2 and the 1-in-50-year hourly wind pressure (HWP) is not greater than 1.2¬†kPa.

[2] 3)Portions of the perimeter of a single open or enclosed space need not comply with Sentence 9.23.13.5.(1), where

[a] a)the roof of the space projects not more than

[i] i)3.5 m from the face of the framing of the nearest parallel braced wall band, and
[ii] ii)half the perpendicular plan dimension,

 

[b] b)that portion of the perimeter structure does not support a floor, and

[c] c)the roof of the space is

[i] i)integral with the roof of the rest of the building with framing members not more than 400 mm o.c., or
[ii] ii)constructed with roof framing not more than 400 mm o.c. fastened to the wall framing (see Table 9.23.3.4. and Article 9.23.9.1. for balloon framing).

 

(See Note A-9.23.13.10.(2).-2020)

 

[3] 4)Walls in detached garages and in accessory buildings serving a single dwelling unit, and the front wall of attached garages serving a single dwelling unit need not comply with Sentence 9.23.13.5.(1) where these walls do not support a floor.

[4] 5)Braced wall panels in the braced wall band at the front of an attached garage serving a single dwelling unit need not comply with Sentence 9.23.13.5.(1), provided

[a] a)the maximum spacing between the front of the garage and the back wall of the garage does not exceed 7.6 m,
[b] b)there is not more than one floor above the garage,
[c] c)not less than 50% of the length of the back wall of the garage is constructed of wood-sheathed braced wall panels, and
[d] d)not less than 25% of the length of the side walls is constructed of wood-sheathed braced wall panels.

 

[5] 1)Except as provided in Sentences (26)-2025 and (37)-2025, one exterior wall of the uppermost storey in each orthogonal direction may be set back from the exterior wall of the storey below, provided the adjacent interior braced wall band of the storey below the setback

[a] a)is spaced not more than 10.6 m from the exterior wall of the storey below the setback wall,
[b] b)consists of braced wall panels that are constructed of a wood-based material in conformance with Sentence 9.23.13.6.(2) Sentence 9.23.13.6.(1),
[c] c)extends to the foundation, and
[d] d)is not taken into consideration when providing braced wall panels constructed of a wood-based material at spacing intervals of not more than 15 m as per Sentence 9.23.13.6.(6) Sentence 9.23.13.6.(3).
[6] 2)Where the exterior wall of the uppermost storey is set back from the exterior wall of the storey below, the roof and floor space supporting the setback wall shall be sheathed with a wood-based material between the exterior wall of the storey below the setback and the adjacent interior braced wall bands of the storey below the setback.

[7] 3)Where the exterior wall of the uppermost storey is set back from the exterior wall of the storey below, the exterior walls perpendicular to the setback wall shall

[a] a)have their top plate connected with nails that are spaced at no greater than half the spacing required in Table 9.23.3.4., and
[b] b)have their top plate splices fastened with twice the number of nails specified in Sentences 9.23.11.4.(4) and (5)Sentence 9.23.11.4.(5) and (6).
[8] 4)The maximum distance between adjacent required braced wall panels in a braced wall band, measured from the edge of the panels, may be increased to 7.3 m provided that, throughout the height of the building, the length of any braced wall panel within the braced wall band is not less than 1.2 m.

[9] 5)The maximum spacing between the centre lines of required braced wall bands given in Table 9.23.13.5. may be increased from 7.6 m to no more than 10.6 m, provided that the interior braced wall band whose spacing is being increased is replaced with an interior braced wall band that

[a] a)consists of braced wall panels that are constructed of a wood-based material in conformance with Sentence 9.23.13.6.(2),
[b] b)extends to the foundation, and
[c] c)is not taken into consideration when providing braced wall panels constructed of a wood-based material at spacing intervals no greater than 15 m as per Sentence 9.23.13.6.(6).

 

[10] 6)For each orthogonal direction of the building, the length of required braced wall panels of one exterior wall given in Table 9.23.13.5. may be reduced from 40% to no less than 25% of the length of the braced wall band, provided an additional parallel and adjacent interior braced wall band is constructed that

[a] a)is spaced not more than 10.6 m from the exterior wall,
[b] b)consists of braced wall panels that are constructed of a wood-based material in conformance with Sentence 9.23.13.6.(2) and whose lengths sum to no less than 25% of the length of the braced wall band,
[c] c)extends to the foundation, and
[d] d)is not taken into consideration when providing braced wall panels constructed of a wood-based material at spacing intervals no greater than 15 m as per Sentence 9.23.13.6.(6).

 

[11] 7)Where the length of required braced wall panels of an exterior wall is reduced as described in Sentence (10)-2020, the ratio of the length of braced wall panels in the respective upper braced wall bands to the length of braced wall panels in the reduced exterior braced wall band shall not exceed 2.

[9.23.13.11.]Simplified Approach for Braced Wall Panel Length

[1] –)This Article may be used for buildings where

[a] –)the seismic design parameter, Smax, is not greater than 0.47 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.60 kPa at that location,
[b] –)the specified roof snow load, as defined in Article 9.4.2.2, is not greater than 2 kPa,
[c] –)the building has plan dimensions not greater than 21.2 m in each direction,
[d] –)the wind exposure is ‚Äúrough terrain‚ÄĚ, as described in Note A-9.23.13.7.(3)- 2025,
[e] –)the greatest eave-to-ridge height of the roof is not greater than 3 m,
[f] –)the braced wall panels are constructed with gypsum board on at least one face,
[g] –)the braced wall bands are continuously wood sheathed where required by Table 9.23.3.5-C, and
[h] –)the construction is limited to normal weight, as described in Clause 9.23.13.2.(3), except as permitted in Sentence (4).

 

[2] –)Except as required in Sentence (3), the minimum total length of all braced wall panels in each braced wall band in each direction shall be in accordance with

[a] –)Table 9.23.13.11-A-2025 where the seismic design parameter, Smax, is not greater than 0.3 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.50 kPa, or
[b] –)Table 9.23.13.11-B-2025 where the seismic design parameter, Smax, is not greater than 0.47 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.60 kPa.

 

Table [9.23.13.11.-A]
Minimum Braced Wall Panel Lengths permitted where HWP ? 0.5 kPa and Smax ? 0.3
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.11.] — ([2] –)
Storey Location Braced Wall Panel Length, m
Diagonal lumber sheathed framing type Gypsum-sheathed framing typePROPOSED CHANGE Table Footnote (1) Wood-sheathed framing type
DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
1.89 9.47

(4.74)

 

5.50

(2.75)

 

4.08

(2.04)

 

3.32

(1.66)

 

3.32 1.76 1.53 1.39 1.26
3.89 19.45

(9.73)

 

11.30

(5.65)

 

8.38

(4.19)

 

6.82

(3.41)

 

6.82 3.61 3.14 2.86 2.59
5.88 NP

(14.71)

 

17.09

(8.55)

 

12.67

(6.34)

 

10.31

(5.16)

 

10.31 5.46 4.74 4.33 3.92
Table [9.23.13.11.-B]
Minimum Braced Wall Panel Lengths permitted where HWP ? 0.6 kPa and Smax ? 0.47
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.11.] — ([2] –)
Storey Location Braced Wall Panel Length, m
Diagonal lumber sheathed framing type Gypsum-sheathed framing typePROPOSED CHANGE Table Footnote (1) Wood-sheathed framing type
DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
2.27 11.36

(5.68)

 

6.60

(3.30)

 

4.89

(2.45)

 

3.98

(1.99)

 

3.98 2.11 1.83 1.67 1.51
4.66 NP

(11.68)

 

13.56

(6.78)

 

10.06

(5.03)

 

8.18

(4.09)

 

8.18 4.34 3.76 3.44 3.11
7.05 NP

(17.96)

 

20.86

(10.43)

 

15.47

(7.74)

 

12.59

(6.30)

 

12.37 6.56 5.69 5.19 4.70

[3] –)Except as permitted in Sentence (4), the minimum total length of all braced wall panels in each braced wall band in the direction perpendicular to a single face of the building clad with masonry veneer with openings shall be in accordance with

[a] –)Table 9.23.13.11-C-2022 where the seismic design parameter, Smax, is not greater than 0.3 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.50 kPa, or
[b] –)Table 9.23.13.11-D-2022 where the seismic design parameter, Smax, is not greater than 0.47 and the 1-in-50 hourly wind pressure (HWP) is not greater than 0.60 kPa.

 

Table [9.23.13.11.-C]
Prescriptive Minimum Braced Wall Panel Lengths for Buildings with Partial Masonry Veneer where HWP ? 0.5 kPa and Smax ? 0.3
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.11.] — ([3] –)
Storey Location Braced Wall Panel Length, m
Diagonal lumber sheathed framing type Gypsum-sheathed framing typePROPOSED CHANGE Table Footnote (1) Wood-sheathed framing type
DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
1.89 9.47

(4.74)

 

5.50

(2.75)

 

4.08

(2.04)

 

3.25

(1.63)

 

3.32 1.76 1.53 1.39 1.26
3.89 19.45

(9.73)

 

11.30

(5.65)

 

8.38

(4.19)

 

6.75

(3.37)

 

6.82 3.61 3.14 2.86 2.59
5.88 NP

(15.01)

 

17.44

(8.72)

 

12.93

(6.46)

 

10.49

(5.25)

 

10.31 5.46 4.74 4.33 3.92
Table [9.23.13.11.-D]
Prescriptive Minimum Braced Wall Panel Lengths for Buildings with Partial Masonry Veneer where HWP ? 0.6 kPa and Smax ? 0.47
Forming¬†Part¬†of¬†Sentence¬†[9.23.13.11.] — ([3] –)
Storey Location Braced Wall Panel Length, m
Diagonal lumber sheathed framing type Gypsum-sheathed framing typePROPOSED CHANGE Table Footnote (1) Wood-sheathed framing type
DWB GWB-A GWB-B GWB-C GWB-D WSP-A WSP-B WSP-C WSP-D WSP-E
2.27 13.12

(6.56)

 

7.63

(3.81)

 

5.66

(2.83)

 

4.89

(2.44)

 

3.98 2.11 1.83 1.67 1.51
4.66 NP

(15.14)

 

17.59

(8.79)

 

13.04

(6.52)

 

10.57

(5.28)

 

8.18 4.34 3.76 3.44 3.11
7.05 NP

(NP)

 

NP

(13.66)

 

20.27

(10.13)

 

16.49

(8.24)

 

12.37 6.56 5.69 5.19 4.70
[4] –)Masonry veneer clad wall portions which are both perpendicular to, and within a braced wall band are permitted to be considered as normal weight.
[5] –)Bracing to resist lateral loads shall be designed and constructed in accordance with Articles 9.23.13.4 to 9.23.13.6 and Articles 9.23.13.8 to 9.23.13.10.

 

Note A-9.23.13. Bracing for Resistance to Lateral Loads.

Subsection 9.23.13., along with Articles 9.4.2.5., 9.23.3.4., 9.23.3.5., 9.23.6.1., 9.23.9.8., 9.23.11.4., 9.23.15.5., 9.29.5.8., 9.29.5.9., 9.29.6.3. and 9.29.9.3. contain design and bracing provisions that address the resistance of light wood-frame structures and non-structural components to wind and earthquake loads .
The bracing provisions were developed based on a combination of performance history and engineering calculations, as are most Part 9 provisions. The placement and construction methods for braced walls were determined by the following approach. The lateral forces were analyzed in accordance with Part 4 for various configurations of buildings in different locations across Canada. The lateral resistance of walls was established using an approach adapted from CSA O86, ‚ÄúEngineering Design in Wood.‚ÄĚ Construction details and required lengths for braced walls were assigneddetermined based on location, building height, wind exposed class and construction weight. This approach relied on the following assumptions:
‚ÄĘ A short-term load duration factor, KD, of 1.25 was used for the calculation of resistance to wind and seismic shear forces.
‚ÄĘ The ductility- and overstrength-related seismic force modification factors, Rd and Ro, were assumed to have the values listed in the following table:
Seismic Force Resisting System (SFRS) Rd Ro
Nailed or screwed wood-based shear walls in combination with gypsum board 3.0 1.7
Nailed or screwed diagonal lumber board shear walls in combination with gypsum board 3.0 1.7
Nailed or screwed gypsum board shear walls 2.0 1.7
‚ÄĘ A level of resistance of up to 50% of the wind or seismic lateral load demand was assumed to be provided by interior partitions, wall finishes, and other non-structural components, such as cabinetry and cladding.
It is important to note that not all buildings satisfying the bracing provisions will have the configurations or details assumed in the calculations, which are necessary to provide adequate resistance against lateral loads. For example, buildings that have fewerlimited interior partitions than assumedand other non-structural components may have a lower lateral resistance than predicted. In such cases, the Part 9 provisions for bracing to resist lateral loads may not be adequate to satisfy the objectives of the NBC, and bracing requirements should instead be determined in accordance with Part 4.
See Note A-9.4.2.5. for more information on the seismic design parameter, Smax, used in the seismic design provisions.

 

Note A-9.23.13.12.(3) Heavy Weights of Construction.

Normal Weight Construction
Normal-weight floor construction (0.5 kPa) accommodates ceramic tile, hardwood, carpet and other finishes weighing no more than 0.25 kPa. Normal-weight roof construction (0.5 kPa) accommodates asphalt shingles, wood shingles, steel roofing and other roofing weighing no more than 0.12 kPa. Normal-weight wall construction (0.4 kPa) accommodates fibre cement board, wood, vinyl, lightweight metal panels weighing no more than 0.10 kPa.

These cladding weights are based on the typical light wood frame construction:

  • Floor assembly: plywood subfloor, 2×12 lumber floor joists at 400 mm o.c. and gypsum board ceiling;
  • Roof assembly: plywood roof sheathing, trusses, R60 insulation, gypsum board ceiling;
  • Wall assembly: OSB exterior sheathing, strapping, 2×6 studs at 400 mm o.c, insulation, gypsum board interior finish

 

Heavy Weight Construction
In a building of ‚Äúheavy weight construction,‚ÄĚ the average dead weight per storey of either the floors, roof or exterior walls is permitted to exceed the value stated in Clause 9.23.13.21.(3)(a), but must not exceed the maximum average dead weights per storeyvalue stated in Clause 9.23.13.21.(3)(b). The maximum average dead weights per storey for the three cases are listed in Table A-9.23.13.1.(3)The heavy weight floor construction provisions account for an additional total dead load of 1.0 kPa compared to the normal weight floor construction, accommodating, for example, a 38 mm normal-weight concrete topping. Heavy-weight roof construction, accommodates lighter roofing materials to be replaced with slate or clay tile shingles weighing up to 0.65 kPa (provided the heavy roofing is not installed over existing normal weight roofing). The heavy-weight roof construction provisions also accommodate the installation of solar panels over normal weight roofing such as asphalt shingles. Solar panels add approximately 0.12 kPa to the roof. Heavy-weight wall construction provisions account for cladding weighing up to 0.85 kPa, when this heavier cladding replaces normal weight cladding. This accommodates cementitious stucco, heavier weight metal panels, and, if averaged with lighter claddings, adhered manufactured or natural stone veneer. Heavy weight wall construction does not accommodate masonry or stone veneer except where advantage can be made of ‚ÄúArea-weighted Average‚ÄĚ. The maximum average dead weights per storey for the three cases are listed in Table A- 9.23.13.1.(3).
Table [9.23.13.12.(3)] A-9.23.13.12.(3)
Maximum Average Dead Weights per Storey for Heavy Weight Construction
Forming Part of Note A-9.23.13.21.(3)
Description of Heavy Weight Construction Maximum Average Dead Weight per Storey, kPa
Floors Partitions and Interior Walls Roof Exterior Walls
Normal weight floors and roof with heavy weight exterior walls 0.5 0.5 0.5 1.2
Normal weight floors and exterior walls with heavy weight roof 0.5 0.5 1.0 0.4
Normal weight exterior walls and roof with heavy weight floors 1.5 0.5 0.5 0.4
Masonry and Stone Veneer Wall Cladding
Braced wall panels that run perpendicular to masonry- and stone veneered walls are required to have a comparatively higher lateral strength to resist increased lateral loading due to the relatively higher wall mass of the masonry. The effects of mass are accounted for using the Kweight factor listed in Table 9.23.13.7-D. Under seismic action, lateral load due to the mass of a masonry or stone veneer is transferred into the wall immediately behind the veneer, which under the load path and by diaphragm action, is transferred into the roof and floors and is resisted by the braced wall panels oriented parallel to the seismic motion (perpendicular to the veneer). Therefore, only braced wall panels running perpendicular to the masonry or stone veneered walls are required to be adjusted by the Kweight adjustment factor. If the entire building is clad with masonry or stone veneer, all braced wall panels are required to be adjusted by the appropriate masonry or stone ‚Äúboth faces‚ÄĚ Kweight adjustment factor. If only two parallel faces of a four-sided building are clad with masonry or stone veneer, only the side-yard braced wall panels are required to be adjusted using the appropriate masonry or stone ‚Äúboth faces‚ÄĚ Kweight adjustment factor. If only one face of the building is clad with masonry or stone veneer, the side-yard braced wall panels are required to be adjusted with the ‚Äúone face‚ÄĚ Kweight adjustment factor.

For buildings clad with masonry veneer, the following veneer products with a bed thickness of not more than 90 mm are considered to meet the weight limit of 1.9 kPa:

  • clay brick masonry veneer
  • concrete block masonry veneer
  • concrete brick masonry veneer
  • concrete stone masonry veneer
  • calcium silicate masonry veneer

 

For buildings clad with stone veneers, natural stone veneer of limestone and sandstone, excluding granite, with a bed thickness of not more than 125 mm are considered to meet the weight limit of 3.2 kPa.
Area-weighted Average
The concept of area-weighted average is an important consideration for cost-effective construction and wall bracing compliance. Depending upon the relative weights and areas of materials, less rigorous bracing requirements could apply to the structure using the concept of ‚Äėarea-weighted average‚Äô. It is based on averaging the cumulative sum of material weights over their respective areas. Averaging of material weights applies per assembly. Using area-weighted average, for example, wall cladding weights can be averaged for the entire building‚Äôs wall areas to determine if normal or heavy construction apply under the per storey average dead weight limits stated in Table A.9.23.13.2.(3). A building with walls partially clad with comparatively heavier materials may qualify as normal weight construction if the area-weight contribution of the normal weight cladding materials combined with that of heavy weight cladding materials, such as stucco, masonry veneer or stone veneer, does not exceed the average dead weight limit of 0.4 kPa for normal weight construction. Similarly, a building with walls partially clad with masonry or stone veneer may qualify as heavy weight construction if the area-weighted average contribution of the normal or heavy weight cladding materials combined with that of masonry or stone veneer does not exceed the average dead weight limit of 1.2 kPa for heavy weight construction. This same concept applies to floor and roof assemblies.
Example: Area-weighted average floor calculation

For example, if a building has 400 square metres of floor area, and 25 square metres of that floor area has a concrete topping (floor assembly = 1.25 kPa), and the remaining 375 square metres has hardwood floors (floor assembly = 0.45 kPa), the area-weighted average dead weight is:

 

1 . 25 kPa 25 m 2 + 0 . 45 kPa 375 m 2 400 m 2 = 0 . 5 kPa 

Therefore, qualifies as normal weight construction.

 

Note A-9.23.13.4. Braced Wall Bands.

Article 9.23.13.4. specifies the required characteristics of braced wall bands and their position in the building. Figures A-9.23.13.4.-A, A-9.23.13.4.-B and A-9.23.13.4.-C illustrate these requirements.
Support of braced wall panels in loadbearing and non-loadbearing walls must conform with Article 9.23.9.8. Cantilevered floor joists must conform with Article 9.23.9.9.
Figure [A-9.23.13.4.-A] A-9.23.13.4.-A
Braced wall bands in an example building section [Clauses 9.23.13.4.(1)(a), (b), (c) and (d)(e)]
Braced wall bands in an example building section [Clauses 9.23.13.4.(1)(a), (b), (c) and (d)(e)]
Figure [A-9.23.13.4.-B] A-9.23.13.4.-B
Lapping bands and building perimeter within braced wall bands [Clause 9.23.13.4.(1)(cd) and Sentence 9.23.13.4.(21)(a)]
Lapping bands and building perimeter within braced wall bands [Clause 9.23.13.4.(1)(cd) and Sentence 9.23.13.4.(21)(a)]
Figure [A-9.23.13.4.-C] A-9.23.13.4.-C
Braced wall band at change in floor level in split-level buildings [Sentence 9.23.13.4.(32)-2020]
Braced wall band at change in floor level in split-level buildings [Sentence 9.23.13.4.(32)-2020]

 

Note A-9.23.13.5.(3) and (4)-2020 Connection of Gypsum-Sheathed Braced Wall Panels to Roof Framing.

Braced wall panels that are sheathed with gypsum board alone have a significantly lower lateral resistance than wood-sheathed braced wall panels. For gypsum-sheathed braced wall panels, the typical lateral bracing of trusses is usually adequate to transfer the lateral loads from the bottom chords to the top chords of the truss.
The connection of interior gypsum-sheathed braced wall panels to trusses also needs to accommodate vertical movement of the roof framing in order to facilitate ‚Äútruss uplift‚ÄĚ and to prevent the gypsum board from cracking.
Figure [A-9.23.13.5.(3) and (4)-2020]
Wood-sheathed braced wall panel to roof framing connection details (Sentence 9.23.13.5.(3)(a) and (b))
Wood-sheathed braced wall panel to roof framing connection details (Sentence 9.23.13.5.(3)(a) and (b))

 

 

Note A-9.23.13.6.(1)-2020 Materials in Braced Wall Panels.

Clause 9.23.13.6.(1)(a)-2020 describes wood-based exterior braced wall panels, which includes gypsum board on the interior, ‚Äėregularly attached‚Äô according to Subsection 9.29.5. This corresponds with framing types WSP-A, WSP-B, WSP-C, WSP-D, WSP F and DWB, with GWB-O on the interior, as described in 9.23.3.5.(3). Clause 9.23.13.6.(1)(b)-2020 describes exterior braced wall panels sheathed with gypsum board only, typically applied to the interior side of the exterior walls, accommodating the option of no wood-based structural sheathing on the exterior side of the braced walls. This corresponds to framing types GWB-O, GWB-A, GWB-B, GWB-F, and GWB-H.

 

 

Note A-9.23.13.6.(3)-2020(5) and (6) Use of Gypsum Board to Provide Required Bracing.

Braced wall panels constructed with gypsum board alone provide less resistance to lateral loads than panels constructed with OSB, waferboard, plywood or diagonal lumber board;. Therefore, Sentence 9.23.13.6.(3)-2020 limits the use of gypsum board to provide the required lateral resistance by requiring that walls in basements and crawl spacesin braced wall panels is restricted by Sentences 9.23.13.6.(5) and (6).
Braced wall panels constructed with gypsum board are permitted in braced wall bands, but Sentence (6) limits the use of such panels by requiring that braced wall panels not more than 15 m apart be constructed with braced wall panels made of wood-based sheathingmaterial at braced wall band intervals of not more than 15 m apart. See Figure A-9.23.13.6.(5) and (6).
Figure [A-9.23.13.6.(3)-2020(5) and (6)] A-9.23.13.6.(5) and (6)
Braced wall panels constructed of wood-based material
Braced wall panels constructed of wood-based material

 

 

Note A-9.23.13.6.(5)-2020 Mixed Braced Wall Panel Framing Types in Braced Wall Bands.

The primary reason for mixed braced wall panel framing types is to accommodate where an interior GWB-sheathed braced wall panel framing type aligns with an exterior WSP braced wall panel framing type, along the same braced wall band as shown in the plan view below. This permission is restricted to GWB- and ‚Äėlow strength‚Äô WSP-sheathed framing types A and B. Mixing high strength or very stiff walls with low strength or less stiff walls has not been sufficiently studied and therefore requires analysis based on engineering principles.
This appendix note provides examples of complying with the requirements of 9.23.13.6.(5) when mixed braced wall panels are present along a braced wall band. Example 1 is the reference case without mixed sheathing types. Compliance to requirements in 9.23.13.6.(5)(a) is demonstrated in Example 2, for the same braced wall band in Example 1.
Example 1 ‚Äď One sheathing type in all braced wall panels
A braced wall band (B) consists of an exterior wall of 1 meter (at braced wall band 2) which continues into the building as an interior wall of 3 m and another interior wall 5 m for a total length = 1 + 3 + 5 = 9 m. The wall construction along B qualifies as GWB-B braced wall panel type. It is determined that a total braced wall panel length of 8 m is required if constructed as GWB-B. Therefore, there is sufficient wall length for the GWB-B braced wall panel along braced wall band B.
Figure [A-9.23.13.6.(5)-2020-A]
One sheathing type in all braced wall panels
One sheathing type in all braced wall panels

Example 2 ‚Äď Mixed sheathing types in all braced wall panels using direct length substitution approach
The exterior walls are constructed with wood sheathing, and qualify as WSP-A braced wall panels. The builder would like to substitute the 1m portion of GWB-B braced wall panel construction with WSP-A exterior braced wall panel. Article 9.23.13.6.(5)(a)-2020 permits a direct substitution, determined using the longest calculated braced wall panel length of all sheathing types in the braced wall band. In this case, the required length of braced wall panel is 8m of GWB-B or 5.5m of WSP-A. Therefore in this scenario, 5m (GWB-B) + 3m (GWB-B) + 1m (WSP-A) = 9m > 8m, meets the requirement in 9.23.13.6.(5)(a)-2020.
Figure [A-9.23.13.6.(5)-2020-B]
Mixed sheathing types in all braced wall panels using direct length substitution approach
Mixed sheathing types in all braced wall panels using direct length substitution approach

 

 

 

Note A-9.23.13.7.(3)-2020 Alternate Procedure to Calculate Wind-related Required Braced Wall Panel Length.

To facilitate calculations of prescribed braced wall panel lengths, the wind-related minimum total unadjusted braced wall panel lengths, Luw, are provided in Table 9.23.13.7.-A-2020 for categories of 1-in-50-year hourly wind pressure (HWP). The values provided within each HWP category are based on the highest HWP in the category, and must be adjusted by the factors provided in Table 9.23.13.7.-C-2020. In lieu of the method given in Sentence 9.23.13.7.(3)-2020, the minimum required total braced wall length for wind, Lw is permitted to be calculated directly using the following equation:

Lw = CWstoreyKWframeHWP(KexpKroofKWspacingKWnumberKgypKsheath) ? BWPmin

where:

CWstorey
= coefficient for storey location, for wind
= 3.84 for braced wall panels supporting roof only
= 7.89 for braced wall panels supporting roof + 1 floor
= 11.93 for braced wall panels supporting roof + 2 floors
KWframe
= adjustment factor for framing type used in lieu of the unadjusted length for wind braced Luw, given in Table A-9.23.13.7.(3)-2020
HWP
= 1‚Äďin-50 year hourly wind pressure, kPa
Kexp
= wind exposure adjustment
= 1.0 for 7.6 m braced wall band spacing
Kroof
= roof eave-to-ridge height adjustment, for wind
= 1.0 for 3 m
KWspacing
= braced wall band spacing adjustment for wind per building plan direction
= 1.0 for 7.6 m braced wall band spacing
KWnumber
= number of braced wall bands adjustment for wind per building plan direction
= 1.0 for no intermediate braced wall bands between exterior walls
Kgyp
= interior gypsum board adjustment
= 1.0 for braced wall panels with interior gypsum board
Ksheath
= intermittent braced wall panels adjustment
= 1.0 for braced wall bands with continuously wood-sheathed exterior walls
BWPmin
= Minimum length of individual braced wall panels as per Table 9.23.13.5.-2020

 

Values for adjustment factors, Kexp, Kroof, KWspacing, KWnumber, Kgyp and Ksheath are provided in Table 9.23.13.7.-B-2020.
Table [9.23.13.7.(3)-2020] A-9.23.13.7.(3)-2020
Wind-related Framing Adjustment Factor, KWframe
Forming¬†Part¬†of¬†Sentence¬†— (–)
Reference Framing Type KWframe
GWB-O 5.36
GWB-A 3.59
GWB-B 3.06
GWB-C 2.88
GWB-D 2.71
GWB-E 2.54
GWB-F 2.04
GWB-G 1.96
GWB-H 1.72
WSP-A 1.00
WSP-B 0.53
WSP-C 0.37
WSP-D 0.29
WSP-E 0.25
WSP-F 0.23
DWB 0.61
When wind acts on the building width, the length of the building (dimension parallel to the wind) is irrelevant to determining the bracing required to resist that wind force. A short building receives the same wind force as a long building with an equivalent width. This concept is illustrated in Figure A-9.23.13.7.(3)-A-2020. As a result, in calculating the length of required wind bracing, the input is the braced wall band spacing (the building width), regardless of building length.
Figure [A-9.23.13.7.(3)-2020-A]
Wind Force on Different Length Buildings
Wind Force on Different Length Buildings

The equation provided in Sentence 9.23.13.7.(3)-2020 is used to calculate the required length of braced wall panels, Lw, within a braced wall band to resist wind acting on the surface perpendicular to the wall line. The unadjusted length, Luw, provided in Table 9.23.13.7.-A- 2020, refers to a reference building with an eave-to-ridge height of 3 m and two exterior braced wall bands spaced 7.6 m apart, located in an urban location. Adjustment factors are applied to account for deviations from the reference building. These adjustment factors are explained below and their values are provided in Table 9.23.13.7.-B-2020.
Figure [A-9.23.13.7.(3)-2020-B]
Eave-to-ridge Height
Eave-to-ridge Height

Kroof accounts for the effect of eave-to-ridge height, as defined in Figure A-9.23.13.7.(3)-B-2020.
Kexp adjusts for wind loading on a building caused by the effects of local terrain. Wind blows at a lower speed in rough terrain and a higher speed in smooth terrain. Rough terrain, such as an urban or suburban setting or wooded terrain extending upwind for a least one km, offers a comparatively sheltered exposure for a building. For rough terrain, Kexp is assigned the value 1.0 and no exposure adjustment is needed for a building located in rough terrain. A building located in an open terrain, sheltered from wind only by the presence of adjacent scattered trees and buildings or other obstacles, or located near open water or shorelines, will experience a higher wind load than would the same building located in rough terrain.
KWspacing accounts for the change in lateral load resistance when the spacing between braced wall bands, X, differs from 7.6 m. When more than two braced wall bands resist lateral load, the increase in resistance is not directly proportional to the increase in the number of braced wall bands.
KWnumber accounts for the distribution of forces when more than two braced wall bands resist wind load, Figure A-9.23.13.5.(3)-C-2020. The same explanation in Note A-9.23.13.7.(4) for KSnumber applies here for KWnumber, except that under wind load the forces are not evenly distributed due to the critical load case occurring when the wind blows at an angle to the building. As a result, KWnumber factor differs slightly from the KSnumber factor. When the spacing of the parallel braced wall bands is not uniform, the average spacing value, as illustrated in Figure A-9.23.13.7.(3)-D-2020, shall be used. Refer to KSnumber for additional information.
Figure [A-9.23.13.7.(3)-2020-C]
Adjustment for number of braced wall bands resisting wind load
Adjustment for number of braced wall bands resisting wind load

Figure [A-9.23.13.7.(3)-2020-D]
Calculation of mean braced wall band spacing for wind when the spacings between adjacent braced wall bands are not uniform
Calculation of mean braced wall band spacing for wind when the spacings between adjacent braced wall bands are not uniform

Where the braced wall band is intermittently sheathed, the lengths of braced wall panels listed in Table 9.23.13.7.-A. shall be increased by the Ksheath factor. Braced wall bands with intermittent braced wall panels permit the use of non-structural sheathing in areas of the wall where bracing is not required. This factor accounts for a lack of additional resistance otherwise provided by structural sheathing above and below openings and on other non-designated braced wall panels within the braced wall band (Figure A-9.23.13.7.(3)-E-2020), as there would be when the entire braced wall line is continuously sheathed (Figure A-9.23.13.7.(3)-F-2020).
Figure [A-9.23.13.7.(3)-2020-E]
Intermittent braced wall panels (Source: A guide to 2018 Wood Wall Bracing Provisions.)
Intermittent braced wall panels (Source: A guide to 2018 Wood Wall Bracing Provisions.)

Figure [A-9.23.13.7.(3)-2020-F]
Continuously sheathed braced wall panels (default) (Source: A guide to 2018 Wood Wall Bracing Provisions.)
Continuously sheathed braced wall panels (default) (Source: A guide to 2018 Wood Wall Bracing Provisions.)

Non-designated wall segments within continuously-sheathed braced wall bands are required to be constructed with wood sheathing, but are not required to use the same sheathing and fastening as used in the designated braced wall panels along the braced wall band. Instead, the non-designated wall segments may be constructed with any of the plywood, OSB, or waferboard element options and corresponding fastening in accordance with Table 9.23.3.5.-A, and anchored in accordance with Sentence 9.23.6.1.(2). Note that when the calculated Lw exceeds the available length of the wall line, a stronger framing type or a closer braced wall band spacing may be considered.

 

 

 

Note A-9.23.13.7.(4)-2020 Alternative Procedure to Calculate the Seismic-related Braced Wall Panel Length.

To facilitate calculations of prescribed braced wall panel lengths, the seismic-related minimum total unadjusted braced wall panel lengths, Lus, are provided in Table 9.23.13.7.-C-2020 for categories of the seismic design parameter, Smax. The values provided within each Smax category are based on the highest Smax in the category, and must be adjusted by the factors provided in Table 9.23.13.7.-D-2020. In lieu of the method given in Sentence 9.23.13.7.(4)-2020, the adjusted braced wall panel length, the minimum required total braced wall length for seismic, Ls, is permitted to be calculated directly using the following equation:

Ls = (CSstoreyCwallsCroofS)(KSframeSmaxKweightKSspacingKSnumberKgypKsheath) ? BWPmin

where:

CSstorey
= coefficient of storey location, for seismic
= 1 for braced wall panels supporting roof only
= 3 for braced wall panels supporting roof + 1 floor
= 5 for braced wall panels supporting roof + 2 floors
Cwalls
= coefficient accounting for the seismic weight based on the depth of the building, for walls, given in Table A-9.23.13.7.(4)-A-2020
Croof
= coefficient accounting for the seismic weight based on the depth of the building, for roof, given in Table A-9.23.13.7.(4)-A-2020
S
= specified roof snow load, kPa (See Article 9.4.2.2)
KSframe
= adjustment factor for framing type given in Table A-9.23.13.7.(4)-B-2020
Smax
= seismic design parameter, listed in Table 9.4.1.1
Kweight
= weight of construction and cladding adjustment, for seismic
= 1.0 for normal weight construction (See Sentence 9.23.13.2.(3))
Ksnow
= roof snow load adjustment, for seismic
= 1.0 for 2 kPa roof snow load (as calculated in accordance with Article 9.4.2.2.)
KSspacing
= braced wall band spacing adjustment for seismic per building plan direction (See Sentence 9.23.13.7.(5))
= 1.0 for 7.6 m braced wall band spacing
KSnumber
= number of braced wall bands adjustment for seismic per building plan direction
= 1.0 for no intermediate braced wall bands between exterior walls
Kgyp
= interior gypsum board adjustment
= 1.0 for braced wall panels with interior gypsum board
Ksheath
= intermittent braced wall panels adjustment
= 1.0 for continuously wood-sheathed braced wall bands
BWPmin
= minimum length of individual braced wall panels as per Table 9.23.13.5.-2020

 

Table [A-9.23.13.7.(4)-2020-A]
Seismic Related Coefficients, Cwalls and Croof
Building dimension parallel to braced wall band, m CwallsPROPOSED CHANGE Table Footnote (1) Croof
3.1 0.38 0.09
6.1 0.60 0.17
9.1 0.83 0.26
12.2 1.06 0.35
15.5 1.29 0.43
18.3 1.52 0.52
Table [A-9.23.13.7.(4)-2020-B]
Seismic Related Framing Adjustment Factor, KSframe
Reference Framing Type KSframe
GWB-O 8.04
GWB-A 5.39
GWB-B 4.58
GWB-C 4.32
GWB-D 4.07
GWB-E 3.81
GWB-F 3.07
GWB-G 2.95
GWB-H 2.58
WSP-A 1.00
WSP-B 0.53
WSP-C 0.46
WSP-D 0.42
WSP-E 0.41
WSP-F 0.38
DWB 0.57
The force demand exerted on a building by seismic motion is directly proportional to the mass of the building. When determining the amount of bracing required to resist seismic forces, the length of the building parallel to the direction of loading is the most important consideration, because mass is generally evenly distributed along the length and width of a building. For a given building width, a longer building has more mass ‚Äď and thus receives greater seismic forces ‚Äď than a shorter building. As a result, the longer building requires a greater amount of bracing. For this reason, in the seismic bracing table, Table 9.23.13.7.-C-2020, the amount of braced wall panel required in a wall line is dependent on the available building depth parallel to the braced wall band being considered, and is less dependent of the width of the building (perpendicular to the direction of the seismic force). This is illustrated in Figure A-9.23.13.7.(4)-A-2020.
Figure [A-9.23.13.7.(4)-2020-A]
Seismic Force on Different Length Buildings
Seismic Force on Different Length Buildings

The equation provided in 9.23.13.7.(4) is used to calculate the total required length of braced wall panels, Ls, within a braced wall band to resist seismic force applied in that direction.
The unadjusted length, Lus, provided in Table 9.23.13.7.-C-2020, refers to a reference building with an eave-to-ridge height of 3 m and two braced wall bands spaced 7.6 m apart, with a roof snow load of 2 kPa. Adjustment factors are applied to account for construction that deviates from the reference building. The values of the adjustment factors are presented in Table 9.23.13.7.-D-2020. The adjustment factors are explained below.
Ksnow accounts for specified roof snow load larger than 2 kPa.
KSspacing accounts for the change in lateral load resistance when the spacing between braced wall bands differs from 7.6 m. When more than two braced wall bands resist lateral load, the increase in resistance is not directly proportional to the increase in the number of braced wall bands.
KSnumber accounts for the distribution of forces when more than two braced wall bands resist seismic load, Figure A-9.23.13.7.(4)-B-2020. At first glance, it may seem counter-intuitive for the factor to increase when there are additional braced wall bands. However, since the braced wall panel lengths are determined based on the braced wall band spacing, the factor is needed to account for the actual distributed loads. Consider a 15 m building with a uniform seismic load of 10 kN/m horizontally applied to the width of a building with two exterior braced wall bands and one interior braced wall band. Equally distributing the seismic load to the three braced wall bands results in an actual force distribution of (15 m x 10 kN/m) / 3 braced wall bands = 50 kN per braced wall band. However, based on the braced wall band spacing, each braced wall band would receive only (10 kN/m x 7.5 m braced wall band spacing) / 2 braced wall bands = 37.5 kN. KSnumber corrects the calculated braced wall panel length by applying, for 3 braced wall bands, a factor of 50 kN/37.5 kN = 1.33. Note that in this case, KSnumber is applied to the unadjusted braced wall panel length for a 7.5 m braced wall band spacing to obtain the total braced wall panel length for each of the threebraced wall bands in the 15 m wide building. As the amount of braced wall bands increases, the effect diminishes, and therefore the highest KSnumber factor applied to 5 braced wall bands is also sufficient for more than 5 braced wall bands. When the spacing of the parallel braced wall bands is not uniform, the average spacing value, as illustrated in Figure A.9.23.13.7.(4)-C-2020, may be used in lieu of the largest spacing.
Figure [A-9.23.13.7.(4)-2020-B]
Adjustment for Number of Braced Wall Bands Resisting Seismic Load
Adjustment for Number of Braced Wall Bands Resisting Seismic Load

Figure [A-9.23.13.7.(4)-2020-C]
Calculation of Mean Braced Wall Band Spacing for Seismic When the Spacings between Adjacent Braced Wall Bands are Not Uniform
Calculation of Mean Braced Wall Band Spacing for Seismic When the Spacings between Adjacent Braced Wall Bands are Not Uniform

As stated above, heavy buildings generate high seismic loads. For buildings that have construction weights higher than normal construction, the total length of braced wall panels needs to be adjusted by the weight of construction factor, Kweight. The value of Kweight depends on whether the building is classified as heavy construction, or it is clad with masonry veneer or stone veneer on one or two building faces, as illustrated in Figure A-9.23.13.7.(4)-2020-D. Note that in the case of masonry veneer or stone veneer clad buildings, only the veneer located on the building faces perpendicular to the direction of seismic load are assumed to contribute to the seismic mass.
Figure [A-9.23.13.7.(4)-2020-D]
Masonry Veneer or Stone Veneer Walls that Contribute to Seismic Force Applied on a Building
Masonry Veneer or Stone Veneer Walls that Contribute to Seismic Force Applied on a Building

The minimum braced wall panel lengths provided in Table 9.23.13.7.-D-2020 assume that gypsum board is attached to the interior face of braced wall panels. If gypsum board is omitted, the braced wall panels are to be adjusted by the Kgyp factor.
Where the braced wall band is intermittently sheathed, the minimum lengths of braced wall panels listed in Table 9.23.13.7.-C-2020 must be increased by the Ksheath factor. Braced wall bands with intermittent braced wall panels permit the use of non-structural sheathing in areas of the wall where bracing is not required. This factor accounts for a lack of additional resistance otherwise provided by structural sheathed above and below openings and on other non-designated braced wall panels within the braced wall band (Figure A-9.23.13.7.(3)-E-2020), as there would be when the entire braced wall band is continuously wood-sheathed (Figure A-9.23.13.7.(3)-F-2020).
Non-designated wall segments within continuously-sheathed braced wall bands are required to be constructed with wood sheathing, but are not required to use the same sheathing and fastening as used in the designated braced wall panels along the braced wall band. Instead, the non-designated wall segments may be constructed with any of the plywood, OSB, or waferboard element options and corresponding fastening in accordance with Table 9.23.3.5.-A, and anchored in accordance with Sentence 9.23.6.1.(2).
The calculation procedure provided in this appendix note may be used to determine the minimum total required braced wall panel lengths for those cases designated as design required (DR) in Table 9.23.13.7.-C-2020. Note that when the calculated Ls exceeds the available length of the wall line, a stronger framing type or a closer braced wall band spacing may be considered.

 

[9.23.16.1.] 9.23.16.1.Required Roof Sheathing

[1] 1)Except where the 1-in-50-year hourly wind pressure (HWP) is less than 0.8 kPa and the seismic spectral accelerationdesign parameter, Sa(0.2)Smax, for Site Class C, is less than or equal to 0.700.47, continuous lumber or panel-type roof sheathing shall be installed to support the roofing.

[9.23.16.5.] 9.23.16.5.Lumber Roof Sheathing

[1] 1)Lumber roof sheathing shall not be more than 286 mm wide and shall be applied so that all ends are supported with end joints staggered.

[2] 2)Lumber roof sheathing shall be installed diagonally, where

[a] a)the seismic spectral accelerationdesign parameter, Sa(0.2)Smax, Site Class C is greater than 0.700.47 but not greater than 1.20.8, or
[b] b)the 1-in-50-year hourly wind pressure (HWP) is equal to or greater than 0.8 kPa but less than 1.20 kPa.

[3] 3)Lumber roof sheathing shall be designed according to Part 4, where

[a] a)the seismic spectral accelerationdesign parameter, Sa(0.2)Smax, for Site Class C is greater than 1.20.8, or
[b] b)the 1-in-50-year hourly wind pressure (HWP) is equal to or greater than 1.20 kPa.

[9.31.6.2.] 9.31.6.2.Equipment and Installation

[1] 3)Where the building is in a location where the spectral accelerationseismic design parameter, Sa(0.2)Smax, for Site Class C is greater than 0.550.37, service water heaters shall be secured to the structure to prevent overturning. (See Note A-9.31.6.2.(3)PROPOSED CHANGE A-9.31.6.2.(3).)

[9.33.4.7.] 9.33.4.7.Structural Movement

[1] 2)Where the building is in a location where the spectral accelerationseismic design parameter, Sa(0.2)Smax, for Site Class C is greater than 0.550.37, heating and air-conditioning equipment with fuel or power connections shall be secured to the structure to resist overturning and displacement. (See Note A-9.31.6.2.(3)PROPOSED CHANGE A-9.31.6.2.(3).)

Impact analysis

The impact analysis looks at the cost difference between a base scenario (2015 NBC provisions with 2015 seismic hazard values) and three other scenarios (Scenario A: 2015 NBC provisions with 2020 seismic hazard values; Scenario B: proposed 2020 NBC provisions with 2020 seismic hazard values excluding changes to the lower seismic and wind trigger levels; and Scenario C: proposed 2020 NBC provisions with 2020 seismic hazard values including changes to the lower seismic and wind trigger levels). Further, Scenarios B and C are broken down into two subcategories to examine both Site Class C and E conditions to simulate the decision to hire a geotechnical engineer to determine the Site Class.

Several iterations of the impact analysis were completed using the seismic design parameters for 15 locations (Vancouver-Richmond, BC; Victoria, BC; Queen Charlotte City, BC; Calgary, AB; Regina, SK; Winnipeg, MB; Toronto, ON; Ottawa, ON; Montr√©al, QC; Sherbrooke, QC; Fredericton, NB; Halifax, NS; St. John‚Äôs, NL; and Whitehorse, YK). For each of these locations a single archetype (two-storey detached house with attached garage, a common suburban home design; refer to supporting documents) was used. The cost for various wall assemblies representing braced wall panels from the 2015 NBC and braced wall framing types included in the proposed change were costed using RS Means ‚Äď 2019 Building Construction Costs Book. The costing data provided by RS Means is based on the US national average. For the purpose of this analysis the costs were converted to Canadian dollars using the average exchange rate from 2018 of 1.2957. The cost analysis does not determine the overall wall costs or building cost; instead it compares the difference in cost between the above noted scenarios.

The impact analysis found that, in general, there will be an increased cost in each of the locations analyzed and, similarly, the majority of locations in Canada when applying the full requirements in the proposed change. Though, the magnitude of the cost increases are relatively small (refer to supporting documents), ranging from 0.156% to 1.065% of the average home building cost (obtained from Altus Group ‚Äď 2019 Canadian Construction Cost Guide).

If the lower triggers of Sa(0.2) < 0.7 and HWP < 0.8 kPa were to be maintained in some form, for the most part, it appears that locations governed by wind will not be affected. Further, based on the cities selected, the majority of locations appear to be unaffected by a straight increase in the seismic hazard values for 2020. However, for those locations in high seismic zones, the increase to seismic hazard values can be more significant. In Victoria, the impact represents 2.295% of the average house cost. The new provisions help these locations; though, an area like Queen Charlotte City is not assisted by the proposed change, unless a favourable Site Class is confirmed by a geotechnical engineer.

Finally, for construction of exterior walls where rigid insulation is used as exterior sheathing in low wind and seismic zones, the impact is greater than typical exterior wall construction, but still remains small with a difference in cost of 0.64% in Toronto and 1.07% in Halifax (sample cities).

Assumptions:

  • Where Part 4 design is required, it is assumed that the wall lengths determined using the prescriptive solutions in Part 9 would be increased by 10% (this is a conservative value).
  • Typical exterior wall construction consists of 11¬†mm OSB sheathing, 2‚Ä̬†x¬†6‚ÄĚ studs at 600¬†mm, batt insulation and 12.7¬†mm gypsum board (not including cladding, air and vapour barrier).
  • Professional fees to design the building to Part 4 are 1% of the cost of the average home cost in Canada.
  • Labour to nail exterior sheathing to the studs represents 25% of the overall labour cost to install sheathing (used when data from RS Means needed to be interpolated).
  • The size of the property does not change for scenarios where the garage needs to be widened to meet Article 9.23.13.10.-2020, which requires minimum braced wall panel lengths to be used (600¬†mm to 750¬†mm).

Limitations:

  • This is a small subset of all the locations in Canada, so that same general conclusions above will not apply everywhere.
  • One archetype was used having two storeys; though, a common style was selected.
  • The analysis is limited to normal weight construction.
  • The analysis does not examine the benefits of finding a Site Class of A, B or D.
  • National averages are used.

Refer to the summary of analysis results and the plan drawings of the archetype (basement, first floor and second floor) attached as supporting documents.

The following committee working reference documents are available upon request:

  • Comments on the analysis results for each location analyzed
  • Presentation to the Standing Committee on Housing and Small Buildings dated August 7, 2019

Enforcement implications

Will require some additional review of building permit applications to ensure that the proper design and construction approach has been taken.

Who is affected

Designers and builders with respect to design, build and construction.

Building owners would bear any increase in costs but would benefit from a reduced probability or degree of property loss in the case of an earthquake.

Supporting Document(s)

OBJECTIVE-BASED ANALYSIS OF NEW OR CHANGED PROVISIONS

[9.4.1.1.] 9.4.1.1. ([1] 1) no attributions
[9.4.1.1.] 9.4.1.1. ([2] 2) no attributions
[9.4.1.1.] 9.4.1.1. ([3] 3) no attributions
[9.4.2.1.] 9.4.2.1. ([1] 1) no attributions
[9.4.2.2.] 9.4.2.2. ([1] 1) [F20OS2.1,OS2.3][F22OS2.3]
[9.4.2.2.] 9.4.2.2. ([1] 1) [F20OP2.1,OP2.3][F22OP2.3]
[9.4.2.2.] 9.4.2.2. ([1] 1) [F22OH1.1,OH1.2,OH1.3]
[9.4.2.2.] 9.4.2.2. ([2] 2) [F20OS2.1]
[9.4.2.2.] 9.4.2.2. ([2] 2) [F20OP2.1]
[9.4.2.2.] 9.4.2.2. ([3] 3) no attributions
[9.4.2.2.] 9.4.2.2. ([4] 4) [F20OS2.1,OS2.3][F22OS2.3]
[9.4.2.2.] 9.4.2.2. ([4] 4) [F20OP2.1,OP2.3][F22OP2.3]
[9.4.2.2.] 9.4.2.2. ([4] 4) [F22OH1.1,OH1.2,OH1.3]
[9.4.2.2.] 9.4.2.2. ([5] 5) no attributions
[9.4.2.3.] 9.4.2.3. ([1] 1) [F20OS2.1]
[9.4.2.3.] 9.4.2.3. ([1] 1) [F20OP2.1]
[9.4.2.4.] 9.4.2.4. ([1] 1) [F20OS2.1]
[9.4.2.4.] 9.4.2.4. ([1] 1) [F20OP2.1]
[9.4.2.5.] — ([1] –) [F20OS2.1]
[9.4.2.5.] — ([1] –) [F20OP2.1]
[9.4.2.5.] — ([2] –) [F20OS2.1]
[9.4.2.5.] — ([2] –) [F20OP2.1]
[9.20.1.1.] 9.20.1.1. ([1] 1) no attributions
[9.20.1.1.] 9.20.1.1. ([2] 2) no attributions
[9.20.1.2.] 9.20.1.2. ([1] 1) no attributions
[9.20.1.2.] 9.20.1.2. ([2] 2) no attributions
[9.23.1.1.] 9.23.1.1. ([1] 1) no attributions
[9.23.1.1.] 9.23.1.1. ([2] 2) no attributions
[9.23.3.1.] 9.23.3.1. ([1] 1) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.1.] 9.23.3.1. ([1] 1) [F20OP2.1][F20,F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.1.] 9.23.3.1. ([1] 1) [F20,F22OS1.2]
[9.23.3.1.] 9.23.3.1. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.1.] 9.23.3.1. ([1] 1) [F22OH4]
[9.23.3.1.] 9.23.3.1. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F20OP2.1][F20,F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F20,F22OS1.2]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F22OH4]
[9.23.3.1.] 9.23.3.1. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F20,F22OS1.2]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F22OH4]
[9.23.3.1.] 9.23.3.1. ([3] 3) [F22OS3.1][F22OS3.7]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F22OH4]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F20,F22OS1.2]
[9.23.3.4.] 9.23.3.4. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F20,F22OS1.2]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F22OH4]
[9.23.3.4.] 9.23.3.4. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.3.4.] 9.23.3.4. ([3] 3) [F20OS2.1][F20,F22OS2.3][F20,F22OS2.5]
[9.23.3.4.] 9.23.3.4. ([3] 3) [F20OP2.1,OP2.5][F20,F22OP2.3][F22OP2.4,OP2.5]
[9.23.3.4.] 9.23.3.4. ([3] 3) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.4.] 9.23.3.4. ([3] 3) [F20,F22OS1.2]
[9.23.3.4.] 9.23.3.4. ([4] 4) [F20OS2.1][F20,F22OS2.3][F20,F22OS2.5]
[9.23.3.4.] 9.23.3.4. ([4] 4) [F20OP2.1,OP2.5][F20,F22OP2.3][F22OP2.4,OP2.5]
[9.23.3.4.] 9.23.3.4. ([4] 4) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.4.] 9.23.3.4. ([4] 4) [F20,F22OS1.2]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F22OH4]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F20,F22OS1.2]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.5.] 9.23.3.5. ([2] 2) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([2] 2) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.5.] 9.23.3.5. ([3] 3) no attributions
[9.23.3.5.] 9.23.3.5. ([3] 3) [F22OS3.7]
[9.23.3.5.] 9.23.3.5. ([3] 3) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([3] 3) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([3] 3) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.5.] 9.23.3.5. ([4] 4) no attributions
[9.23.3.5.] 9.23.3.5. ([5] 5) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([5] 5) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([5] 5) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.5.] 9.23.3.5. ([5] 5) [F22OH4]
[9.23.3.5.] 9.23.3.5. ([5] 5) [F20,F22OS1.2]
[9.23.3.5.] 9.23.3.5. ([5] 5) [F22OS3.1][F22OS3.7]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F22OH4]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F20,F22OS1.2]
[9.23.3.5.] 9.23.3.5. ([6] 6) [F22OS3.1][F22OS3.7]
[9.23.3.5.] 9.23.3.5. ([7] 7) [F20,F22OS2.1]
[9.23.3.5.] 9.23.3.5. ([7] 7) [F20OP2.1][F22OP2.4]
[9.23.3.5.] 9.23.3.5. ([7] 7) [F22OH4]
[9.23.3.5.] 9.23.3.5. ([7] 7) [F22OS3.1]
[9.23.3.5.] 9.23.3.5. ([7] 7) [F20OS1.2]
[9.23.3.5.] 9.23.3.5. ([8] 8) [F20OS2.1][F20,F22OS2.5][F20,F22OS2.3]
[9.23.3.5.] 9.23.3.5. ([8] 8) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.3.5.] 9.23.3.5. ([8] 8) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.6.1.] 9.23.6.1. ([1] 1) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1.] 9.23.6.1. ([1] 1) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1.] 9.23.6.1. ([1] 1) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1.] 9.23.6.1. ([1] 1) [F22OH4]
[9.23.6.1.] 9.23.6.1. ([1] 1) [F20OS3.1]
[9.23.6.1.] 9.23.6.1. ([2] 2) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1.] 9.23.6.1. ([2] 2) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1.] 9.23.6.1. ([2] 2) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1.] 9.23.6.1. ([2] 2) [F22OH4]
[9.23.6.1.] 9.23.6.1. ([2] 2) [F20OS3.1]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F22OH4]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OS3.1]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F22OH4]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([3 4] 4) [F20OS3.1]
[9.23.6.1.] 9.23.6.1. ([5] 5) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1.] 9.23.6.1. ([5] 5) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1.] 9.23.6.1. ([5] 5) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1.] 9.23.6.1. ([5] 5) [F22OH4]
[9.23.6.1.] 9.23.6.1. ([5] 5) [F20,F22OS3.1]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F22OH4]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OS3.1]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OH1.1,OH1.2,OH1.3]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F22OH4]
[9.23.6.1. 9.23.6.1.] 9.23.6.1. ([6 7] 6) [F20OS3.1]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F22OH4]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F22OS1.2]
[9.23.11.4.] 9.23.11.4. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F22OH4]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F20,F22OS1.2]
[9.23.11.4.] 9.23.11.4. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F22OH4]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F20,F22OS1.2]
[9.23.11.4.] 9.23.11.4. ([3] 3) [F22OS3.1][F22OS3.7]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F22OH4]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F20,F22OS1.2]
[9.23.11.4.] 9.23.11.4. ([4] 4) [F22OS3.1][F22OS3.7]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OH4]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OS1.2]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OS3.1][F22OS3.7]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OH4]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OS1.2]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OS3.1][F22OS3.7]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OH4]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F20,F22OS1.2]
[9.23.11.4. 9.23.11.4.] 9.23.11.4. ([5 6] 5) [F22OS3.1][F22OS3.7]
[9.23.11.4.] — ([8] –) [F20OS2.1,OS2.5][F22OS2.5][F20,F22OS2.3]
[9.23.11.4.] — ([8] –) [F20OP2.1,OP2.5][F22OP2.4,OP2.5][F20,F22OP2.3]
[9.23.11.4.] — ([8] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.11.4.] — ([8] –) [F22OH4]
[9.23.11.4.] — ([8] –) [F20,F22OS1.2]
[9.23.11.4.] — ([8] –) [F22OS3.1][F22OS3.7]
[9.23.13.1.] 9.23.13.1. ([1] 1) no attributions
[9.23.13.1.] 9.23.13.1. ([2] 2) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.1.] 9.23.13.1. ([2] 2) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.1.] 9.23.13.1. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.1.] 9.23.13.1. ([2] 2) [F20,F22OS1.2]
[9.23.13.1.] 9.23.13.1. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.13.1.] 9.23.13.1. ([2] 2) [F20,F22OH4]
[9.23.13.2.] 9.23.13.2. ([1] 1) no attributions
[9.23.13.2.] 9.23.13.2. ([2] 2) no attributions
[9.23.13.2.] — ([3] –) no attributions
[9.23.13.3.] 9.23.13.3. ([1] 1) no attributions
[9.23.13.3.] 9.23.13.3. ([2] 2) no attributions
[9.23.13.4.] 9.23.13.4. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.4.] 9.23.13.4. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.4.] 9.23.13.4. ([1] 1) [F20,F22OS1.2]
[9.23.13.4.] 9.23.13.4. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.4.] 9.23.13.4. ([1] 1) [F20,F22OH4]
[9.23.13.4.] 9.23.13.4. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F20,F22OS1.2]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.13.4.] 9.23.13.4. ([2] 2) [F20,F22OH4]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F20,F22OS1.2]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F22OS3.1][F22OS3.7]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F20,F22OH4]
[9.23.13.4.] 9.23.13.4. ([3] 3) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] — ([3] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] — ([3] –) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] — ([3] –) [F20,F22OS1.2]
[9.23.13.5.] — ([3] –) [F22OS3.1][F22OS3.7]
[9.23.13.5.] — ([3] –) [F20,F22OH4]
[9.23.13.5.] — ([3] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] — ([4] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] — ([4] –) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] — ([4] –) [F20,F22OS1.2]
[9.23.13.5.] — ([4] –) [F22OS3.1][F22OS3.7]
[9.23.13.5.] — ([4] –) [F20,F22OH4]
[9.23.13.5.] — ([4] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([5 2] 3) no attributions
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([6 3] 4) no attributions
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([7 4] 5) no attributions
[9.23.13.6.] 9.23.13.6. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([1] 1) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.6.] 9.23.13.6. ([1] 1) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F22OS3.1][F22OS3.7]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F22OS3.1][F22OS3.7]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([3] 6) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.6.] 9.23.13.6. ([4] 2) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([4] 2) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([4] 2) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([4] 2) [F22OS3.1]
[9.23.13.6.] 9.23.13.6. ([4] 2) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([5] 3) no attributions
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F22OS3.1][F22OS3.7]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([6] 4) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F20,F22OS1.2]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F22OS3.1][F22OS3.7]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F20,F22OH4]
[9.23.13.6.] 9.23.13.6. ([7] 5) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.6.] 9.23.13.6. ([5] 3) no attributions
[9.23.13.6.] 9.23.13.6. ([5] 3) no attributions
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.7.] — ([5] –) no attributions
[9.23.13.7.] — ([5] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.7.] — ([5] –) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.7.] — ([5] –) [F20,F22OS1.2]
[9.23.13.7.] — ([5] –) [F22OS3.1][F22OS3.7]
[9.23.13.7.] — ([5] –) [F20,F22OH4]
[9.23.13.7.] — ([5] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.8.] — ([1] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.8.] — ([1] –) [F20OP2.1,OS2.3,OS2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.8.] — ([1] –) [F20,F22OS1.2]
[9.23.13.8.] — ([1] –) [F22OS3.1][F22OS3.7]
[9.23.13.8.] — ([1] –) [F20,F22OH4]
[9.23.13.8.] — ([1] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.8.] — ([2] –) no attributions
[9.23.13.8.] — ([2] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.8.] — ([2] –) [F20OP2.1,OS2.3,OS2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.8.] — ([2] –) [F20,F22OS1.2]
[9.23.13.8.] — ([2] –) [F22OS3.1][F22OS3.7]
[9.23.13.8.] — ([2] –) [F20,F22OH4]
[9.23.13.8.] — ([2] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.8.] — ([3] –) no attributions
[9.23.13.8.] — ([3] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.8.] — ([3] –) [F20OP2.1,OS2.3,OS2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.8.] — ([3] –) [F20,F22OS1.2]
[9.23.13.8.] — ([3] –) [F22OS3.1][F22OS3.7]
[9.23.13.8.] — ([3] –) [F20,F22OH4]
[9.23.13.8.] — ([3] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.8.] — ([4] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.8.] — ([4] –) [F20OP2.1,OS2.3,OS2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.8.] — ([4] –) [F20,F22OS1.2]
[9.23.13.8.] — ([4] –) [F22OS3.1][F22OS3.7]
[9.23.13.8.] — ([4] –) [F20,F22OH4]
[9.23.13.8.] — ([4] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.9.] — ([1] –) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.9.] — ([1] –) [F20OP2.1,OS2.3,OS2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.9.] — ([1] –) [F20,F22OS1.2]
[9.23.13.9.] — ([1] –) [F22OS3.1][F22OS3.7]
[9.23.13.9.] — ([1] –) [F20,F22OH4]
[9.23.13.9.] — ([1] –) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.10.] — ([1] –) no attributions
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([5 2] 3) no attributions
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([6 3] 4) no attributions
[9.23.13.5. 9.23.13.10.] 9.23.13.5. ([7 4] 5) no attributions
[9.23.13.10.] 9.23.13.7. ([5] 1) no attributions
[9.23.13.10.] 9.23.13.7. ([6] 2)
[9.23.13.10.] 9.23.13.7. ([7] 3) no attributions
[9.23.13.10.] 9.23.13.7. ([8] 4) no attributions
[9.23.13.10.] 9.23.13.7. ([9] 5) no attributions
[9.23.13.10.] 9.23.13.7. ([10] 6) no attributions
[9.23.13.10.] 9.23.13.7. ([11] 7) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.10.] 9.23.13.7. ([11] 7) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.10.] 9.23.13.7. ([11] 7) [F20,F22OS1.2]
[9.23.13.10.] 9.23.13.7. ([11] 7) [F22OS3.1][F22OS3.7]
[9.23.13.10.] 9.23.13.7. ([11] 7) [F20,F22OH4]
[9.23.13.10.] 9.23.13.7. ([11] 7) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.10.] — ([1] –) no attributions
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OS1.2]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F22OS3.1][F22OS3.7]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH4]
[9.23.13.5.] 9.23.13.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
— (–) no attributions
— (–) no attributions
— (–) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
— (–) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
— (–) [F20,F22OS1.2]
— (–) [F22OS3.1][F22OS3.7]
— (–) [F20,F22OH4]
— (–) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.16.1.] 9.23.16.1. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.16.1.] 9.23.16.1. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.16.1.] 9.23.16.1. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.16.5.] 9.23.16.5. ([1] 1) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.5]
[9.23.16.5.] 9.23.16.5. ([1] 1) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.5]
[9.23.16.5.] 9.23.16.5. ([1] 1) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.16.5.] 9.23.16.5. ([1] 1) [F20,F22OS1.2]
[9.23.16.5.] 9.23.16.5. ([2] 2) [F20OS2.1,OS2.3,OS2.5][F22OS2.3,OS2.4,OS2.5]
[9.23.16.5.] 9.23.16.5. ([2] 2) [F20OP2.1,OP2.3,OP2.5][F22OP2.3,OP2.4,OP2.5]
[9.23.16.5.] 9.23.16.5. ([2] 2) [F20,F22OS1.2]
[9.23.16.5.] 9.23.16.5. ([2] 2) [F20,F22OH1.1,OH1.2,OH1.3]
[9.23.16.5.] 9.23.16.5. ([3] 3) no attributions
[9.31.6.2.] 9.31.6.2. ([1] 3) [F23OS3.4]
[9.31.6.2.] 9.31.6.2. ([1] 3)