1) This 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)roof and wall planes are clad, sheathed or braced on at least one side,
b)the small repetitive structural members are spaced not more than 600 mm o.c.,
c)the constructions do not serve as foundations,
d)the specified live load on supported subfloors and floor framing does not exceed 2.4 kPa, and
e)the span of any structural member does not exceed 12.20 m.
(See Appendix A.)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.
1) All members shall be so framed, anchored, fastened, tied and braced to provide the
necessary strength and rigidity.
1) Ends of wood joists, beams and other members framing into masonry or concrete shall
be treated to prevent decay where the bottom of the member is at or below ground level,
or a 12 mm air space shall be provided at the end and sides of the member.
2) Air spaces required in Sentence (1) shall not be blocked by insulation, vapour barriers or airtight materials.
1) Except as permitted in Sentence (2), wood framing members that are not pressure-treated with a wood preservative and that are supported on concrete in contact with the ground or fill shall be separated from the concrete by not less than 0.05 mm polyethylene film or Type S roll roofing.
2) Dampproofing material referred to in Sentence (1) is not required where the wood member is at least 150 mm above the ground.
1) Lumber shall conform to Subsection 9.3.2.
1) Unless otherwise indicated, nails specified in this Section shall be common steel
wire nails or common spiral nails, conforming to CSA B111, “Wire Nails, Spikes and
Staples.”
2) Wood screws specified in this Section shall conform to ANSI/ASME B18.6.1, “Wood Screws (Inch Series).”
(See Appendix A.)
1) All nails shall be long enough so that not less than half their required length penetrates
into the second member.
1) Splitting of wood members shall be minimized by staggering the nails in the direction
of the grain and by keeping nails well in from the edges. (See Appendix A.)
1) Except as provided in Sentence (2), nailing of framing shall conform to Table 9.23.3.4.
2) Where the bottom wall plate or sole plate of an exterior wall is not nailed to 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)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)tying the wall framing to the floor framing by galvanized-metal strips
i)50 mm wide,
ii)not less than 0.41 mm thick,
iii)spaced not more than 1.2 m apart, and
iv)fastened at each end with at least two 63 mm nails.
| Table 9.23.3.4. Nailing for Framing Forming Part of Sentence 9.23.3.4.(1) |
||
| Construction Detail | Minimum Length of Nails, mm | Minimum Number or Maximum Spacing of Nails |
|---|---|---|
| Floor joist to plate – toe nail | 82 | 2 |
| 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 9.23.13.8.) | 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 |
| Stud 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 top wall plates | 76 | 600 mm (o.c.) |
| Bottom wall plate or sole plate to joists or blocking (exterior walls)(1) | 82 | 400 mm (o.c.) |
| Interior walls to framing or subflooring | 82 | 600 mm (o.c.) |
| Horizontal member over openings in non-loadbearing walls – each end | 82 | 2 |
| Lintels to studs | 82 | 2 at each end |
| Ceiling joist to plate – toe nail each end | 82 | 2 |
| Roof rafter, roof truss or roof joist to plate – toe nail | 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 9.23.13.8. |
| Gusset plate to each rafter at peak | 57 | 4 |
| Rafter to ridge board – toe nail – end nail | 82 | 3 |
| Collar tie to rafter – 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 – 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.) |
| Notes to Table 9.23.3.4. | |
|
|
|
| (1) | See Sentence 9.23.3.4.(2). |
1) Fastening of sheathing and subflooring shall conform to Table 9.23.3.5.
| Table 9.23.3.5. Fasteners for Sheathing and Subflooring Forming Part of Sentence 9.23.3.5.(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 from 10 mm to 20 mm thick | 51 | 45 | n/a | 51 | |
| Plywood, OSB or waferboard over 20 mm thick | 57 | 51 | n/a | n/a | |
2) 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.
3) 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.
4) Flooring screws shall not be less than 3.2 mm in diameter.
1) Spans provided in this Subsection for joists, beams and lintels supporting floors
shall apply only where
a)the floors serve residential areas as described in Table 4.1.5.3., or
b)the uniformly distributed live load on the floors does not exceed that specified for residential areas as described in Table 4.1.5.3.
2) Spans for joists, beams and lintels supporting floors shall be determined according
to Subsection 4.1.3. where the supported floors
a)serve other than residential areas, or
b)support a uniform live load in excess of that specified for residential areas.
1) Except as required in Sentence (2) and Article 9.23.13.10., spans for wood joists and rafters shall conform to the spans shown in Tables A-1 to A-7 for the uniform live loads shown in the Tables. (See Article 9.4.2.2.)
2) Spans for floor joists that are not selected from Tables A-1 and A-2 and that are required to be designed for the same loading conditions, shall not exceed the design requirements for uniform loading and vibration criteria. (See Appendix A.)
3) Spans for built-up wood and glued-laminated timber floor beams shall conform to the
spans in Tables A-8 to A-11. (See Article 9.4.2.2.)
4) Spans for roof ridge beams shall conform to the spans in Table A-12 for the uniform snow load shown. (See Articles 9.4.2.2. and 9.23.13.8.)
1) The spans for steel floor beams with laterally supported top flanges shall conform
to Table 9.23.4.3. (See Appendix A.)
| Table 9.23.4.3. Maximum Spans for Steel Beams Supporting Floors in Dwelling Units(1) Forming Part of Sentence 9.23.4.3.(1) |
|||||||
| Section | Supported Joist Length, m (half the sum of joist spans on both sides of the beam) | ||||||
|---|---|---|---|---|---|---|---|
| 2.4 | 3.0 | 3.6 | 4.2 | 4.8 | 5.4 | 6.0 | |
| One Storey Supported | |||||||
| W150 x 22 | 5.5 | 5.2 | 4.9 | 4.8 | 4.6 | 4.5 | 4.3 |
| W200 x 21 | 6.5 | 6.2 | 5.9 | 5.7 | 5.4 | 5.1 | 4.9 |
| W200 x 27 | 7.3 | 6.9 | 6.6 | 6.3 | 6.1 | 5.9 | 5.8 |
| W200 x 31 | 7.8 | 7.4 | 7.1 | 6.8 | 6.6 | 6.4 | 6.2 |
| W250 x 24 | 8.1 | 7.6 | 7.3 | 7.0 | 6.6 | 6.2 | 5.9 |
| W250 x 33 | 9.2 | 8.7 | 8.3 | 8.0 | 7.7 | 7.5 | 7.3 |
| W250 x 39 | 10.0 | 9.4 | 9.0 | 8.6 | 8.4 | 8.1 | 7.9 |
| W310 x 31 | 10.4 | 9.8 | 9.4 | 8.9 | 8.4 | 8.0 | 7.6 |
| W310 x 39 | 11.4 | 10.7 | 10.2 | 9.8 | 9.5 | 9.2 | 9.0 |
| Two Storeys Supported | |||||||
| W150 x 22 | 4.9 | 4.4 | 4.1 | 3.8 | 3.5 | 3.4 | 3.2 |
| W200 x 21 | 5.6 | 5.1 | 4.6 | 4.3 | 4.1 | 3.8 | 3.7 |
| W200 x 27 | 6.4 | 6.1 | 5.6 | 5.3 | 4.9 | 4.7 | 4.4 |
| W200 x 31 | 6.9 | 6.5 | 6.2 | 5.8 | 5.4 | 5.1 | 4.9 |
| W250 x 24 | 6.8 | 6.1 | 5.6 | 5.2 | 4.9 | 4.6 | 4.4 |
| W250 x 33 | 8.2 | 7.7 | 7.0 | 6.5 | 6.1 | 5.8 | 5.5 |
| W250 x 39 | 8.8 | 8.3 | 7.8 | 7.2 | 6.8 | 6.4 | 6.1 |
| W310 x 31 | 8.7 | 7.8 | 7.2 | 6.7 | 6.2 | 5.9 | 5.6 |
| W310 x 39 | 10.0 | 9.3 | 8.5 | 7.9 | 7.4 | 7.0 | 6.7 |
| Notes to Table 9.23.4.3. | |
|
|
|
| (1) | See Appendix A. |
2) Beams described in Sentence (1) shall at least meet the requirements for Grade 350 W steel contained in CAN/CSA-G40.21, “Structural Quality Steel.”
1) Except as permitted in Sentence (2), where a floor is required to support a concrete topping, the joist spans shown in Table A-1 or the spacing of the members shall be reduced to allow for the loads due to the topping.
2) Where a floor is required to support a concrete topping, joist spans are permitted
to be selected from Table A-2 provided the concrete
a)is 38 to 51 mm thick,
b)is normal weight,
c)is placed directly on the subflooring, and
d)has not less than 20 MPa compressive strength after 28 days.
3) Where a floor is required to support a concrete topping not more than 51 mm thick, the allowable beam spans shown in Tables A-8 to A-11 shall be multiplied by 0.8 or the supported length of the floor joists shall be reduced to allow for the loads due to the topping.
1) Where a roof is required to support an additional uniform dead load from roofing materials such as concrete roofing tile, or materials other than as specified in Section 9.27., such as clay roofing tiles, the additional load shall be allowed for by reducing
a)the spans for roof joists and rafters in Tables A-4 to A-7, or the spacing of the members, and
b)the spans for ridge beams and lintels in Tables A-12 to A-16. (See A-9.23.4.2. in Appendix A.)
1) Holes drilled in roof, floor or ceiling framing members shall be not larger than one-quarter
the depth of the member and shall be located not less than 50 mm from the edges, unless
the depth of the member is increased by the size of the hole.
1) Floor, roof and ceiling framing members are permitted to be notched provided the notch
is located on the top of the member within half the joist depth from the edge of bearing
and is not deeper than one-third the joist depth, unless the depth of the member is
increased by the size of the notch.
1) Wall studs shall not be notched, drilled or otherwise damaged so that the undamaged
portion of the stud is less than two-thirds the depth of the stud if the stud is loadbearing or 40 mm if the stud is non-loadbearing, unless the weakened studs are suitably reinforced.
1) Top plates in walls shall not be notched, drilled or otherwise weakened to reduce
the undamaged width to less than 50 mm unless the weakened plates are suitably reinforced.
1) Roof truss members shall not be notched, drilled or otherwise weakened unless such
notching or drilling is allowed for in the design of the truss.
1) Except as required by Sentence 9.23.6.3.(1), building frames shall be anchored to the foundation unless a structural analysis of wind and earthquake pressures shows anchorage is not required.
2) Except as provided in Article 9.23.6.3., anchorage shall be provided by embedding the ends of the first floor joists in concrete, or 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) Anchor bolts referred to in Sentence (2) shall be fastened to the sill plate with nuts and washers and shall be embedded not less than 100 mm in the foundation and so designed that they may be tightened without withdrawing them from the foundation.
1) Except as provided in Sentences (2) and (3), exterior columns and posts shall be anchored to resist uplift and lateral movement.
2) Except as provided in Sentence (3), where columns or posts support balconies, decks, verandas or other exterior platforms, and the distance from finished ground to the underside of the joists is not more than
600 mm,
a)the columns or posts shall be anchored to the foundation to resist uplift and lateral movement, or
b)the supported joists or beams shall be directly anchored to the ground to resist uplift.
3) Anchorage is not required for platforms described in Sentence (2) that
a)are not more than 1 storey in height,
b)are not more than 55 m2 in area,
c)do not support a roof, and
d)are not attached to another structure, unless it can be demonstrated that differential movement will not adversely affect the performance of the structure to which the platform is attached.
1) Buildings not more than 4.3 m wide and not more than 1 storey in building height that are not anchored in accordance with Sentence 9.23.6.1.(1) shall be anchored in conformance with the requirements of CSA Z240.10.1, “Site Preparation, Foundation, and Anchorage of Mobile Homes.”
1) Where sill plates provide bearing for the floor system, they shall be not less than
38 mm by 89 mm material.
1) Sill plates shall be
a)levelled by setting them on a full bed of mortar, or
b)laid directly on the foundation if the top of the foundation is level.
(See also Article 9.23.2.3.)2) The joint between the sill plate for exterior walls and the foundation shall be sealed in accordance with Subsection 9.25.3.
1) Beams shall have even and level bearing and the bearing at end supports shall be not
less than 89 mm long, except as stated in the notes to Tables A-8 to A-11.
1) Exterior steel beams shall be shop primed.
1) Where a beam is made up of individual pieces of lumber that are nailed together, the
individual members shall be 38 mm or greater in thickness and installed on edge.
2) Except as permitted in Sentence (3), where individual members of a built-up beam are butted together to form a joint, the joint shall occur over a support.
3) Where a beam is continuous over more than one span, individual members are permitted
to be butted together to form a joint at or within 150 mm of the end quarter points
of the clear spans, provided the quarter points are not those closest to the ends
of the beam.
4) Members joined at quarter points shall be continuous over adjacent supports.
5) Joints in individual members of a beam that are located at or near the end quarter
points shall not occur in adjacent members at the same quarter point and shall not
reduce the effective beam width by more than half.
6) Not more than one butt joint shall occur in any individual member of a built-up beam
within any one span.
7) Except as provided in Sentence (8), where 38 mm members are laid on edge to form a built-up beam, individual members shall be nailed together with a double row of nails not less than 89 mm in length,
spaced not more than 450 mm apart in each row with the end nails located 100 mm to
150 mm from the end of each piece.
8) Where 38 mm members in built-up wood beams are not nailed together as provided in
Sentence (7), they shall be bolted together with not less than 12.7 mm diam bolts equipped with washers and spaced not more than 1.2 m o.c., with the end bolts located not more than
600 mm from the ends of the members.
1) Except when supported on ribbon boards, floor joists shall have not less than 38 mm
length of end bearing.
2) Ribbon boards referred to in Sentence (1) shall be not less than 19 mm by 89 mm lumber let into the studs.
1) Floor joists may be supported on the tops of beams or may be framed into the sides
of beams.
2) When framed into the side of a wood beam, joists referred to in Sentence (1) shall be supported on
a)joist hangers or other acceptable mechanical connectors, or
b)not less than 38 mm by 64 mm ledger strips nailed to the side of the beam, except that 38 mm by 38 mm ledger strips may be used provided each joist is nailed to the beam by not less than four 89 mm nails, in addition to the nailing for the ledger strip required in Table 9.23.3.4.
3) When framed into the side of a steel beam, joists referred to in Sentence (1) shall be supported on the bottom flange of the beam or on not less than 38 mm by 38 mm lumber bolted to the web with not less than 6.3 mm diam bolts spaced not more
than 600 mm apart.
4) Joists referred to in Sentence (3) shall be spliced above the beam with not less than 38 mm by 38 mm lumber at least 600 mm long to support the flooring.
5) Not less than a 12 mm space shall be provided between the splice required in Sentence (4) and the beam to allow for shrinkage of the wood joists.
1) Except as provided in Sentence 9.23.9.4.(1), bottoms of floor joists shall be restrained from twisting at each end by toe-nailing to the supports, end-nailing to the header joists or by providing continuous strapping,
blocking between the joists or cross-bridging near the supports.
1) Except as permitted by Sentence (5), where strapping is specified in Table A-1, it shall be
a)not less than 19 mm by 64 mm, nailed to the underside of floor joists,
b)located not more than 2 100 mm from each support or other rows of strapping, and
c)fastened at each end to a sill or header.
2) Where bridging is specified in Table A-1, it shall consist of not less than 19 mm by 64 mm or 38 mm by 38 mm cross bridging located not more than 2 100 mm from each support or other rows of bridging.
3) Where bridging and strapping are specified in Table A-1,
a)bridging shall
i)comply with Sentence (2), or
ii)consist of 38 mm solid blocking located not more than 2 100 mm from each support or other rows of bridging and securely fastened between the joists, and
b)except as provided in Sentence (5), strapping shall comply with Sentence (1) and be installed under the bridging.
4) Bridging specified in Table A-2 shall consist of
a)bridging as described in Sentence (2), or
b)38 mm solid blocking located not more than 2 100 mm from each support or other rows of bridging and securely fastened between the joists.
5) Strapping described in Sentence (1) and Clause (3)(b) is not required where
a)furring strips complying with Table 9.29.3.1. are fastened directly to the joists, or
b)a panel-type ceiling finish complying with Subsection 9.29.5., 9.29.6., 9.29.7., 9.29.8., or 9.29.9. is attached directly to the joists.
6) Where a ceiling attached to wood furring is specified in Table A-2,
a)the ceiling finish shall consist of gypsum board, plywood or OSB not less than 12.7 mm thick, and
b)the furring shall be
i)19 mm by 89 mm wood furring spaced at not more than 600 mm o.c., or
ii)19 mm by 64 mm wood furring spaced at not more than 400 mm o.c.
1) Header joists around floor openings shall be doubled when they exceed 1.2 m in length.
2) The size of header joists exceeding 3.2 m in length shall be determined by calculations.
1) Trimmer joists around floor openings shall be doubled when the length of the header
joist exceeds 800 mm.
2) When the header joist exceeds 2 m in length the size of the trimmer joists shall be
determined by calculations.
1) When tail joists and header joists are supported by the floor framing, they shall
be supported by suitable joist hangers or nailing in accordance with Table 9.23.3.4.
1) Non-loadbearing walls parallel to the floor joists shall be supported by joists beneath the wall or on blocking between the joists.
2) Blocking referred to in Sentence (1) for the support of non-loadbearing walls shall be not less than 38 mm by 89 mm lumber, spaced not more than 1.2 m apart.
3) Non-loadbearing interior walls at right angles to the floor joists are not restricted as to location.
4) Loadbearing interior walls parallel to floor joists shall be supported by beams or walls of sufficient strength to transfer safely the specified live loads to the vertical supports.
5) Loadbearing interior walls at right angles to floor joists shall be located not more than 900 mm from the joist support when the wall does not support a floor, and not more than 600 mm
from the joist support when the wall supports one or more floors, unless the joist
size is designed to support such loads.
1) Floor joists supporting roof loads shall not be cantilevered more than 400 mm beyond
their supports where 38 mm by 184 mm joists are used and not more than 600 mm beyond
their supports where 38 mm by 235 mm or larger joists are used.
2) The cantilevered portions referred to in Sentence (1) shall not support floor loads from other storeys unless calculations are provided to show that the design resistances of the cantilevered joists are not exceeded.
3) Where cantilevered floor joists described in Sentences (1) and (2) are at right angles to the main floor joists, the tail joists in the cantilevered portion shall extend inward away from the cantilever support a distance equal to not
less than 6 times the length of the cantilever, and shall be end nailed to an interior
doubled header joist in conformance with Table 9.23.3.4.
1) The size and spacing of studs shall conform to Table 9.23.10.1.
| Table 9.23.10.1. Size and Spacing of Studs Forming Part of Sentence 9.23.10.1.(1) |
||||
| Type of Wall | Supported Loads (including dead loads) | Minimum Stud Size, mm |
Maximum Stud Spacing, mm |
Maximum Unsupported Height, m |
|---|---|---|---|---|
| Interior | No load | 38 x 38 | 400 | 2.4 |
| 38 x 89 flat(1) | 400 | 3.6 | ||
| Attic not accessible by a stairway | 38 x 64 | 600 | 3.0 | |
| 38 x 64 flat(1) | 400 | 2.4 | ||
| 38 x 89 | 600 | 3.6 | ||
| 38 x 89 flat(1) | 400 | 2.4 | ||
| Attic accessible by a stairway plus one floor Roof load plus one floor Attic not accessible by stairway plus 2 floors |
38 x 89 | 400 | 3.6 | |
| Roof load Attic accessible by a stairway Attic not accessible by a stairway plusone floor |
38 x 64 | 400 | 2.4 | |
| 38 x 89 | 600 | 3.6 | ||
| Attic accessible by a stairway plus 2 floors Roof load plus 2 floors |
38 x 89 | 300 | 3.6 | |
| 64 x 89 | 400 | 3.6 | ||
| 38 x 140 | 400 | 4.2 | ||
| Attic accessible by a stairway plus 3 floors Roof load plus 3 floors |
38 x 140 | 300 | 4.2 | |
| Exterior | Roof with or without attic storage | 38 x 64 | 400 | 2.4 |
| 38 x 89 | 600 | 3.0 | ||
| Roof with or without attic storage plus one floor | 38 x 89 | 400 | 3.0 | |
| 38 x 140 | 600 | 3.0 | ||
| Roof with or without attic storage plus 2 floors | 38 x 89 | 300 | 3.0 | |
| 64 x 89 | 400 | 3.0 | ||
| 38 x 140 | 400 | 3.6 | ||
| Roof with or without attic storage plus 3 floors | 38 x 140 | 300 | 1.8 | |
| Notes to Table 9.23.10.1. | |
|
|
|
| (1) | See Article 9.23.10.3. |
1) Except as provided in Sentence (2), each exterior wall in each storey shall be braced with at least one diagonal brace conforming to Sentence (3).
2) Bracing is not required where walls
a)have an interior finish conforming to the requirements of Section 9.29., or
b)where the walls are
i)clad with panel type siding,
ii)diagonally sheathed with lumber, or
iii)sheathed with plywood, OSB, waferboard, gypsum or fibreboard sheathing.
3) Where bracing is required, it shall
a)consist of not less than 19 mm by 89 mm wood members,
b)be applied to the studs at an angle of approximately 45° to the horizontal, and
c)extend the full height of the wall on each storey.
4) Bracing described in Sentence (3) shall be nailed to each stud and wall plate by at least two 63 mm nails.
5) Where loadbearing interior walls are not finished in accordance with Sentence (2), blocking or strapping shall be fastened to the studs at midheight to prevent sideways buckling.
1) Except as permitted in Sentences (2) and (3), all studs shall be placed at right angles to the wall face.
2) Studs on the flat are permitted to be used in gable ends of roofs that contain only
unfinished space or in non-loadbearing interior walls within the limits described in Article 9.23.10.1.
3) Wall studs that support only a load from an attic not accessible by a stairway are
permitted to be placed on the flat within the limits permitted in Article 9.23.10.1. provided
a)the studs are clad on not less than one side with plywood, OSB or waferboard sheathing fastened to the face of the studs with a structural adhesive, and
b)the portion of the roof supported by the studs does not exceed 2.1 m in width.
1) Wall studs shall be continuous for the full storey height except at openings and shall not be spliced except by fingerjoining with a structural adhesive. (See Appendix A.)
1) Corners and intersections shall be designed to provide adequate support for the vertical
edges of interior finishes, sheathing and cladding materials, and in no instance shall
exterior corners be framed with less than the equivalent of 2 studs.
2) Where the vertical edges of interior finishes at wall intersections are supported
at vertical intervals by blocking or furring, the vertical distance between such supports
shall not exceed the maximum distance between supports specified in Section 9.29.
1) Where the lintel spanning the opening is more than 3 m long, studs shall be tripled
on each side of the opening so that
a)the two inner studs on each side extend from the bottom of the supported lintel to the top of the bottom wall plate, and
b)the outer stud on each side extends from the bottom of the top wall plate to the bottom wall plate.
2) Except as provided in Sentence (3), where the lintel spanning the opening is not more than 3 m long, studs shall be doubled on each side of the opening so that
a)the inner studs on each side extend from the bottom of the supported lintel to the top of the bottom wall plate, and
b) the outer stud on each side extends from the bottom of the top wall plate to the bottom wall plate.
3) Single studs are permitted to be used on either side of openings
a)in non-loadbearing interior walls not required to have fire-resistance ratings, provided the studs extend from the top wall plate to the bottom wall plate, or
b)in loadbearing or non-loadbearing interior or exterior walls, provided
i)the opening is less than and within the required stud spacing, and
ii)no 2 such openings of full stud-space width are located in adjacent stud spaces.
(See Appendix A.)1) Except as provided in Sentence (2), wall plates shall be
a)not less than 38 mm thick, and
b)not less than the required width of the wall studs.
2) In non-loadbearing walls and in loadbearing walls where the studs are located directly over framing members, the bottom wall plate is permitted to be 19 mm thick.
1) A bottom wall plate shall be provided in all cases.
2) The bottom plate in exterior walls shall not project more than one-third the plate
width over the support.
1) Except as permitted in Sentences (2) to (4), at least 2 top plates shall be provided in loadbearing walls.
2) A single top plate is permitted to be used in a section of a loadbearing wall containing a lintel provided the top plate forms a tie across the lintel.
3) A single top plate is permitted to be used in loadbearing walls where the concentrated loads from ceilings, floors and roofs are not more than 50 mm to one side of the supporting studs and in all non-loadbearing walls.
4) The top plates need not be provided in a section of loadbearing wall containing a lintel provided the lintel is tied to the adjacent wall section with not less than
a)75 mm by 150 mm by 0.91 mm thick galvanized steel, or
b)19 mm by 89 mm by 300 mm wood splice nailed to each wall section with at least three 63 mm nails.
1) Joints in the top plates of loadbearing walls shall be staggered not less than one stud spacing.
2) The top plates in loadbearing walls shall be lapped or otherwise tied at corners and intersecting walls in accordance with Sentence (4).
3) Joints in single top plates used with loadbearing walls shall be tied in accordance with Sentence (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.
1) Except as provided in Sentence (2), openings in non-loadbearing walls shall be framed with not less than 38 mm material the same width as the studs, securely nailed to adjacent studs.
2) Openings for doors in non-loadbearing walls required to be fire separations with a fire-resistance rating shall be framed with the equivalent of at least two 38 mm thick members that are the same width as the wall plates.
1) Openings in loadbearing walls greater than the required stud spacing shall be framed with lintels designed to carry the superimposed loads to adjacent studs. (See A-9.23.10.6.(3) in Appendix A. )
2) Except as provided in Sentence 9.23.12.3.(2), where 2 or more members are used in lintels, they shall be fastened together with not less than 82 mm nails in a double row, with nails not more than 450 mm apart in
each row.
3) Lintel members are permitted to be separated by filler pieces.
1) Spans and sizes of wood lintels shall conform to the spans shown in Tables A-12 to A-16
a)for buildings of residential occupancy,
b)where the wall studs exceed 38 mm by 64 mm in size,
c)where the spans of supported joists do not exceed 4.9 m, and
d)where the spans of trusses do not exceed 9.8 m.
2) In loadbearing exterior and interior walls of 38 mm by 64 mm framing members, lintels shall consist of
a)64 mm thick members on edge, or
b)38 mm thick and 19 mm thick members fastened together with a double row of nails not less than 63 mm long and spaced not more than 450 mm apart.
3) Lintels referred to in Sentence (2)
a)shall be not less than 50 mm greater in depth than those shown in Tables A-12 to A-16 for the maximum spans shown, and
b)shall not exceed 2.24 m in length.
1) Roof rafters and joists and ceiling joists shall be continuous or shall be spliced
over vertical supports that extend to suitable bearing.
1) Roof and ceiling framing members shall be doubled on each side of openings greater
than 2 rafter or joist spacings wide.
1) The length of end bearing of joists and rafters shall be not less than 38 mm.
1) Rafters shall be located directly opposite each other and tied together at the peak,
or may be offset by their own thickness if nailed to a ridge board not less than 17.5 mm
thick.
2) Except as permitted in Sentence (3), framing members shall be connected by gusset plates or nailing at the peak in conformance with Table 9.23.3.4.
3) Where the roof framing on opposite sides of the peak is assembled separately, such
as in the case of factory-built houses, the roof framing on opposite sides is permitted
to be fastened together with galvanized-steel strips not less than 200 mm by 75 mm
by 0.41 mm thick spaced not more than 1.2 m apart and nailed at each end to the framing
by at least two 63 mm nails.
1) Rafters shall be shaped at supports to provide even bearing surfaces and supported
directly above the exterior walls.
1) Hip and valley rafters shall be not less than 50 mm greater in depth than the common
rafters and not less than 38 mm thick, actual dimension.
1) Ceiling joists and collar ties of not less than 38 mm by 89 mm lumber are permitted
to be assumed to provide intermediate support to reduce the span for rafters and joists
where the roof slope is 1 in 3 or greater.
2) Collar ties referred to in Sentence (1) more than 2.4 m long shall be laterally supported near their centres by not less than 19 mm by 89 mm continuous members at right angles to the collar ties.
3) Dwarf walls and struts are permitted to be used to provide intermediate support to
reduce the span for rafters and joists.
4) When struts are used to provide intermediate support they shall be not less than 38 mm
by 89 mm material extending from each rafter to a loadbearing wall at an angle of not less than 45° to the horizontal.
5) When dwarf walls are used for rafter support, they shall be framed in the same manner
as loadbearing walls and securely fastened top and bottom to the roof and ceiling framing to prevent over-all movement.
6) Solid blocking shall be installed between floor joists beneath dwarf walls referred
to in Sentence (5) that enclose finished rooms.
1) Except as provided in Sentence (4), roof rafters and joists shall be supported at the ridge of the roof by
a)a loadbearing wall extending from the ridge to suitable bearing, or
b)a ridge beam supported by not less than 89 mm length of bearing.
2) Except as provided in Sentence (3), the ridge beam referred to in Sentence (1) shall conform to the sizes and spans shown in Table A-12, provided
a)the supported rafter or joist length does not exceed 4.9 m, and
b)the roof does not support any concentrated loads.
3) The ridge beam referred to in Sentence (1) need not comply with Sentence (2) where
a)the beam is of not less than 38 mm by 140 mm material, and
b)the beam is supported at intervals not exceeding 1.2 m by not less than 38 mm by 89 mm members extending vertically from the ridge to suitable bearing.
4) When the roof slope is 1 in 3 or more, ridge support need not be provided when the
lower ends of the rafters are adequately tied to prevent outward movement.
5) Ties required in Sentence (4) are permitted to consist of tie rods or ceiling joists forming a continuous tie for opposing rafters and nailed in accordance with Table 9.23.13.8.
| Table 9.23.13.8. Rafter-to-Joist Nailing (Unsupported Ridge) Forming Part of Sentences 9.23.13.8.(5)and (6) |
|||||||||||||
| Roof Slope | Rafter Spacing, mm | Minimum Number of Nails not less than 76 mm Long | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rafter Tied to every Joist | Rafter Tied to Joist every 1.2 m | ||||||||||||
| Building Width up to 8 m | Building Width up to 9.8 m | Building Width up to 8 m | Building Width up to 9.8 m | ||||||||||
| Roof Snow Load, kPa | Roof Snow Load, kPa | Roof Snow Load, kPa | Roof Snow Load, kPa | ||||||||||
| 1.0 or less | 1.5 | 2.0 or more | 1.0 or less | 1.5 | 2.0 or more | 1.0 or less | 1.5 | 2.0 or more | 1.0 or less | 1.5 | 2.0 or more | ||
| 1 in 3 | 400 | 4 | 5 | 6 | 5 | 7 | 8 | 11 | — | — | — | — | — |
| 600 | 6 | 8 | 9 | 8 | — | — | 11 | — | — | — | — | — | |
| 1 in 2.4 | 400 | 4 | 4 | 5 | 5 | 6 | 7 | 7 | 10 | — | 9 | — | — |
| 600 | 5 | 7 | 8 | 7 | 9 | 11 | 7 | 10 | — | — | — | — | |
| 1 in 2 | 400 | 4 | 4 | 4 | 4 | 4 | 5 | 6 | 8 | 9 | 8 | — | — |
| 600 | 4 | 5 | 6 | 5 | 7 | 8 | 6 | 8 | 9 | 8 | — | — | |
| 1 in 1.71 | 400 | 4 | 4 | 4 | 4 | 4 | 4 | 5 | 7 | 8 | 7 | 9 | 11 |
| 600 | 4 | 4 | 5 | 5 | 6 | 7 | 5 | 7 | 8 | 7 | 9 | 11 | |
| 1 in 1.33 | 400 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 5 | 6 | 5 | 6 | 7 |
| 600 | 4 | 4 | 4 | 4 | 4 | 5 | 4 | 5 | 6 | 5 | 6 | 7 | |
| 1 in 1 | 400 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 5 |
| 600 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 5 | |
6) Ceiling joists referred to in Sentence (5) shall be fastened together with at least one more nail per joist splice than required for the rafter to joist connection shown in Table 9.23.13.8.
7) Members referred to in Sentence (6) are permitted to be fastened together either directly or through a gusset plate.
1) Roof joists supporting a finished ceiling, other than plywood, OSB or waferboard,
shall be restrained from twisting along the bottom edges by means of furring, blocking,
cross bridging or strapping conforming to Article 9.23.9.3.
1) Except as permitted in Sentence (2), ceiling joists supporting part of the roof load from the rafters shall be not less than 25 mm greater in depth than required for ceiling joists not supporting part of
the roof load.
2) When the roof slope is 1 in 4 or less, the ceiling joist sizes referred to in Sentence (1) shall be determined from the span tables for roof joists.
1) Roof trusses which are not designed in accordance with Part 4 shall
a)be capable of supporting a total ceiling load (dead load plus live load) of 0.35 kPa plus two and two-thirds times the specified live roof load for 24 h, and
b)not exceed the deflections shown in Table 9.23.13.11. when loaded with the ceiling load plus one and one-third times the specified roof snow load for 1 h.
| Table 9.23.13.11. Maximum Roof Truss Deflections Forming Part of Sentence 9.23.13.11.(1) |
||
| Truss Span | Type of Ceiling | Maximum Deflection |
|---|---|---|
| 4.3 m or less | Plaster or gypsum board | 1/360 of the span |
| Other than plaster or gypsum board | 1/180 of the span | |
| Over 4.3 m | Plaster or gypsum board | 1/360 of the span |
| Other than plaster or gypsum board | 1/240 of the span | |
2) The joint connections used in trusses described in Sentence (1) shall be designed in conformance with the requirements in Subsection 4.3.1. (See Appendix A.)
3) Where the length of compression web members in roof trusses described in Sentence (1) exceeds 1.83 m, such web members shall be provided with continuous bracing to prevent buckling.
4) Bracing required in Sentence (3) shall consist of not less than 19 mm by 89 mm lumber nailed at right angles to the web members near their centres with at least two 63 mm nails for each member.
5) Where the ability of a truss design to satisfy the requirements of Sentence (1) is demonstrated by testing, it shall consist of a full scale load test carried out in conformance with CSA S307-M, “Load Test Procedure for Wood Roof Trusses for Houses
and Small Buildings.”
6) Where the ability of a truss design to satisfy the requirements of Sentence (1) is demonstrated by analysis, it shall be carried out in accordance with good engineering practice such as described in “Truss Design Procedures and Specifications for Light
Metal Plate Connected Wood Trusses,” published by the Truss Plate Institute of Canada.
1) Subflooring shall be provided beneath finish flooring where the finish flooring does
not have adequate strength to support the specified live loads (see Subsection 9.30.3.).
1) Except as provided in Sentence (2), wood-based panels for subfloors shall conform to
a)CSA O121-M, “Douglas Fir Plywood,”
b)CSA O151, “Canadian Softwood Plywood,”
c)CSA O153-M, “Poplar Plywood,”
d)CAN/CSA-O325.0, “Construction Sheathing,” or
e)CSA O437.0, “OSB and Waferboard.”
2) Particleboard subflooring may be used only where a building is constructed in a factory so that the subfloor will not be exposed to the weather.
3) Subflooring described in Sentence (2) shall conform to grade D-2 or D-3 in ANSI A208.1, “Particleboard, Mat-Formed Wood.”
4) Subflooring described in Sentence (2) shall have its upper surface and all edges treated to restrict water absorption, where the subfloor is used in bathrooms, kitchens, laundry rooms or other areas subject
to periodic wetting. (See Appendix A.)
1) Where the edges of panel-type subflooring are required to be supported (see Sentence 9.30.2.1.(2)), such support shall consist of tongue-and-groove panel edges or not less than 38 mm by 38 mm blocking securely nailed between framing members.
1) Plywood subflooring shall be installed with the surface grain at right angles to the
joists and with joints parallel to floor joists staggered.
2) OSB subflooring conforming to CAN/CSA-O325.0, “Construction Sheathing,” or to O-1 and O-2 grades in CSA O437.0, “OSB and Waferboard,” and waferboard subflooring
conforming to R-1 grade in CSA O437.0 shall be installed so that the direction of
face orientation is at right angles to the joists and the joints parallel to the floor
joists are staggered. (See Appendix A.)
1) Except as provided in Sentences (2) and (3), subfloors shall conform to either Table 9.23.14.5.A. or Table 9.23.14.5.B.
| Table 9.23.14.5.A Thickness of Subflooring Forming Part of Sentences 9.23.14.5.(1)and 9.23.15.7.(1) |
||||
| MaximumSpacing of Supports, mm | Minimum Thickness, mm | |||
|---|---|---|---|---|
| Plywood and OSB, O-2 Grade | OSB, O-1 Grade, and Waferboard, R-1 Grade | Particleboard | Lumber | |
| 400 | 15.5 | 15.9 | 15.9 | 17.0 |
| 500 | 15.5 | 15.9 | 19.0 | 19.0 |
| 600 | 18.5 | 19.0 | 25.4 | 19.0 |
| Table 9.23.14.5.B Rating for Subfloor when Applying CAN/CSA-O325.0 Forming Part of Sentences 9.23.14.5.(1) and 9.23.15.7.(1) |
||
| Maximum Spacing of Supports, mm | Panel Mark | |
|---|---|---|
| Subfloor | Used with Panel-Type Underlay | |
| 400 | 1F16 | 2F16 |
| 500 | 1F20 | 2F20 |
| 600 | 1F24 | 2F24 |
2) Where the finished flooring consists of not less than 19 mm matched wood strip flooring
laid at right angles to joists spaced not more than 600 mm o.c., subflooring shall
be permitted to consist of not less than
a)12.5 mm thick plywood,
b)12.5 mm thick OSB conforming to O-2 grade,
c)12.7 mm thick OSB conforming to O-1 grade,
d)12.7 mm thick waferboard conforming to R-1 grade, or
e) OSB conforming to 2R32/2F16 grade.
3) Except where the flooring consists of ceramic tiles applied with adhesive, where a
separate panel-type underlay or concrete topping is applied to a subfloor on joists
spaced not more than 400 mm o.c., the subfloor is permitted to consist of not less
than
a)12.5 mm thick plywood,
b)12.5 mm thick OSB conforming to O-2 grade,
c)12.7 mm thick OSB conforming to O-1 grade,
d)12.7 mm thick waferboard conforming to R-1 grade, or
e) OSB conforming to 2R32/2F16 grade.
1) When resilient flooring is applied directly to an OSB, waferboard, particleboard or
plywood subfloor, the subfloor shall be fastened to the supports with annular grooved
nails.
1) Lumber subflooring shall be laid at an angle of not less than 45° to the joists.
2) Lumber subflooring shall be fully supported at the ends on solid bearing.
3) Lumber for subflooring shall be of uniform thickness and not more than 184 mm wide.
1) Except as provided in Section 9.26., continuous lumber or panel-type roof sheathing shall be installed to support the roofing.
1) Wood-based panels used for roof sheathing shall conform to the requirements of
a)CSA O121-M, “Douglas Fir Plywood,”
b)CSA O151, “Canadian Softwood Plywood,”
c)CSA O153-M, “Poplar Plywood,”
d)CAN/CSA-O325.0, “Construction Sheathing,” or
e)CSA O437.0, “OSB and Waferboard.”
1) Plywood roof sheathing shall be installed with the surface grain at right angles to
the roof framing.
2) OSB roof sheathing conforming to CAN/CSA-O325.0, “Construction Sheathing,” or to O-1 and O-2 grades as specified in CSA O437.0, “OSB and Waferboard,” shall be
installed with the direction of face orientation at right angles to the roof framing
members. (See A-9.23.14.4.(2) in Appendix A.)
1) Panel-type sheathing board shall be applied so that joints perpendicular to the roof
ridge are staggered where
a)the sheathing is applied with the surface grain parallel to the roof ridge, and
b)the thickness of the sheathing is such that the edges are required to be supported.
2) A gap of not less than 2 mm shall be left between sheets of plywood, OSB or waferboard.
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.
1) Where panel-type roof sheathing requires edge support, the support shall consist of
metal H clips or not less than 38 mm by 38 mm blocking securely nailed between framing
members.
1) The thickness or rating of roof sheathing on a flat roof used as a walking deck shall
conform to either Table 9.23.14.5.A. or Table 9.23.14.5.B. for subfloors.
2) The thickness or rating of roof sheathing on a roof not used as a walking deck shall
conform to either Table 9.23.15.7. or Table 9.23.15.7.
3) Asphalt-coated or asphalt-impregnated fibreboard not less than 11.1 mm thick conforming
to CAN/ULC-S706, “Wood Fibre Thermal Insulation for Buildings,” is permitted to be
used as a roof sheathing over supports spaced not more than 400 mm o.c. provided the
roofing consists of
a)a continuous sheet of galvanized steel not less than 0.33 mm in thickness, or
b)a continuous sheet of aluminum not less than 0.61 mm in thickness.
4) All edges of sheathing described in Sentence (3) shall be supported by blocking or framing.
| Table 9.23.15.7.A Thickness of Roof Sheathing Forming Part of Sentence 9.23.15.7.(2) |
|||||
| Maximum Spacing of Supports, mm (in.) |
Minimum Thickness, mm | ||||
|---|---|---|---|---|---|
| Plywood, and OSB, O-2 Grade | OSB, O-1 Grade, and Waferboard, R-1 Grade | Lumber | |||
| Edges Supported | Edges Unsupported | Edges Supported | Edges Unsupported | ||
| 300 | 7.5 | 7.5 | 9.5 | 9.5 | 17.0 |
| 400 | 7.5 | 9.5 | 9.5 | 11.1 | 17.0 |
| 600 (24) | 9.5 | 12.5 | 11.1 | 12.7 | 19.0 |
| Table 9.23.15.7.B Rating for Roof Sheathing When Applying CAN/CSA-O325.0 Forming Part of Sentence 9.23.15.7.(2) |
||
| Maximum Spacing of Supports, mm | Panel Mark | |
|---|---|---|
| Edges Supported | Edges Unsupported | |
| 400 | 2R16 | 1R16 |
| 500 | 2R20 | 1R20 |
| 600 | 2R24 | 1R24 |
1) Exterior walls and gable ends shall be sheathed when the exterior cladding requires
intermediate fastening between supports or if the exterior cladding requires solid
backing.
1) Where wall sheathing is required, it shall conform to either Table 9.23.16.2.A. or Table 9.23.16.2.B.
| Table 9.23.16.2.A Wall Sheathing Thickness and Specifications Forming Part of Sentence 9.23.16.2.(1) |
|||
| Type of Sheathing | Minimum Thickness, mm(1) | Material Standards | |
|---|---|---|---|
| With Supports 400 mm o.c. | With Supports 600 mm o.c. | ||
| Fibreboard (insulating) | 9.5 | 11.1 | CAN/ULC-S706 |
| Gypsum sheathing | 9.5 | 12.7 | CAN/CSA-A82.27-M ASTM C 79/C 79M ASTM C 1177/C 1177M ASTM C 1396/C 1396M |
| Lumber | 17.0 | 17.0 | See Table 9.3.2.1. |
| Mineral Fibre, Rigid Board, Type 2 | 25 | 25 | CAN/ULC-S702 |
| OSB, O-2 Grade | 6.0 | 7.5 | CSA O437.0 |
| OSB, O-1 Grade, and Waferboard, R-1 Grade | 6.35 | 7.9 | CSA O437.0 |
| Phenolic, faced | 25 | 25 | CAN/CGSB-51.25-M |
| Plywood (exterior type) | 6.0 | 7.5 | CSA O121-M CSA O151 CSA O153-M |
| Polystyrene, Types 1 and 2 | 38 | 38 | CAN/ULC-S701 |
| Polystyrene, Types 3 and 4 | 25 | 25 | CAN/ULC-S701 |
| Polyurethane and Polyisocyanurate Type 1, faced | 38 | 38 | CAN/ULC-S704 |
| Polyurethane and Polyisocyanurate Types 2 and 3, faced | 25 | 25 | CAN/ULC-S704 |
| Notes to Table 9.23.16.2.A | |
|
|
|
| (1) | See also Sentences 9.27.5.1.(2) to (4). |
| Table 9.23.16.2.B Rating for Wall Sheathing when Applying CAN/CSA-O325.0 Forming Part of Sentence 9.23.16.2.(1) |
|
| Maximum Spacing of Supports, mm | Panel Mark |
|---|---|
| 400 | W16 |
| 500 | W20 |
| 600 | W24 |
1) Gypsum sheathing, rigid insulation and fibreboard shall not be used for the attachment
of cladding materials.
1) Lumber wall sheathing shall be applied so that all ends are supported.
2) Where lumber wall sheathing is required to provide bracing according to Article 9.23.10.2., it shall be applied with end joints staggered.
1) A gap of not less than 2 mm shall be left between sheets of plywood, OSB, waferboard
or fibreboard.
1) Where the bottom portions of mansard style roofs are vented, the vertical framing
members behind the sloping portions shall be considered on the same basis as exterior
wall studs and shall conform to Articles 9.27.3.2. to 9.27.3.6.