jswizzle3737/ontario_laws_and_regs huggingface dataset:
9.22.5.1. Hearth Extension (1) Except as required in Sentence (2), fireplaces shall have a noncombustible hearth extending not less than 400 mm in front of the fireplace opening measured from the facing, and not less than 200 mm beyond each side of the fireplace opening. (2) Where the fire chamber floor is elevated more than 150 mm above the hearth, the dimension of the hearth measured perpendicular to the plane of the fireplace opening shall be increased by not less than (a) 50 mm for an elevation above 150 mm and not more than 300 mm, and (b) an additional 25 mm for every 50 mm in elevation above 300 mm.
9.22.5.2. Support of Hearth (1) Except as permitted in Sentence (2), the fire chamber floor and hearth shall be supported on a reinforced concrete slab not less than a 100 mm thick at its supports and, if cantilevered, not less than 50 mm thick at its unsupported edge. (2) A hearth for a fireplace with an opening raised not less than 200 mm from a combustible floor is permitted to be supported on that floor provided the requirements of Clauses 5.3.6.5. to 5.3.6.7. of CAN/CSA-A405-M, “Design and Construction of Masonry Chimneys and Fireplaces” are followed. 9.22.6.Damper
9.22.6.1. Required Damper and Size (1) The throat of every fireplace shall be equipped with a metal damper sufficiently large to cover the full area of the throat opening. 9.22.7.Smoke Chamber
9.22.7.1. Slope of Smoke Chamber (1) The sides of the smoke chamber connecting a fireplace throat with a flue shall not be sloped at an angle greater than 45° to the vertical.
9.22.7.2. Wall Thickness (1) The thickness of masonry walls surrounding the smoke chamber shall be not less than 190 mm at the sides, front and back, except that the portions of the back exposed to the outside may be 140 mm thick. 9.22.8.Factory-Built Fireplaces
9.22.8.1. Conformance to Standard (1) Factory-built fireplaces and their installation shall conform to CAN/ULC S610-M, “Factory-Built Fireplaces”. 9.22.9.Clearance of Combustible Material
9.22.9.1. Clearance to the Fireplace Opening (1) Combustible material shall not be placed on or near the face of a fireplace within 150 mm of the fireplace opening, except that where the combustible material projects more than 38 mm out from the face of the fireplace above the opening, such material shall be at least 300 mm above the top of the opening.
9.22.9.2. Metal Exposed to the Interior (1) Metal exposed to the interior of a fireplace such as the damper control mechanism shall have at least a 50 mm clearance from any combustible material on the face of the fireplace where such metal penetrates through the face of the fireplace.
9.22.9.3. Clearance to Combustible Framing (1) Not less than a 100 mm clearance shall be provided between the back and sides of a solid fuel burning fireplace and combustible framing, except that a 50 mm clearance is permitted where the fireplace is located in an exterior wall. (2) Not less than a 50 mm clearance shall be provided between the back and sides of the smoke chamber of a solid fuel burning fireplace and combustible framing, except that a 25 mm clearance is permitted where the fireplace is located in an exterior wall.
9.22.9.4. Heat Circulating Duct Openings (1) The clearance of combustible material above heat circulating duct openings from those openings shall be not less than (a) 300 mm where the combustible material projects more than 38 mm from the face, and (b) 150 mm where the projection is less than 38 mm. 9.22.10.Fireplace Inserts
9.22.10.1. Installation Standard (1) Fireplace inserts and hearth mounted stoves vented through the throat of a fireplace shall conform to ULC S628, “Standard for Fireplace Inserts”.
9.22.10.2. Installation (1) The installation of fireplace inserts and hearth mounted stoves vented through the throat of a fireplace shall conform to CAN/CSA-B365-M, “Installation Code for Solid-Fuel Burning Appliances and Equipment”. (2) Fireplace inserts and hearth mounted stoves vented through the throat of a fireplace described in Sentence (1) may be installed in existing fireplaces only if a minimum thickness of 190 mm of solid masonry is provided between the smoke chamber and any existing combustible materials, unless the insert is listed for lesser clearances. (3) A fireplace insert installed in a masonry fireplace shall have (a) a listed metal chimney liner installed from the insert collar to the top of the chimney, (b) a direct sealed connection to the chimney flue where such provision is part of an insert conforming to Sentence 9.22.10.1.(1), or (c) a direct sealed connection to the smoke chamber and a cleanout provided to any inaccessible part of the smoke chamber. Section 9.23.Wood-Frame Construction 9.23.1.Scope
9.23.1.1. Application (1) This Section applies to conventional wood-frame construction in which the framing members are spaced not more than 600 mm o.c. (2) The requirements in this Section with regard to floor framing, subflooring and their fastenings apply to floors for which the design live load does not exceed 2.4 kPa. (3) The requirements in this Section with regard to wall framing and its fastenings apply to walls which support floors for which the design live load does not exceed 2.4 kPa on any floor. (4) Where the conditions in Sentences (2) or (3) are exceeded, the design of the framing and fastening shall conform to Subsection 4.3.1.
9.23.1.2. Post, Beam and Plank Construction (1) Post, beam and plank construction and plank frame wall construction shall conform to Article 9.4.1.2. 9.23.2.General
9.23.2.1. Strength and Rigidity (1) All members shall be so framed, anchored, fastened, tied and braced to provide the necessary strength and rigidity.
9.23.2.2. Protection from Decay (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 air tight materials.
9.23.2.3. Protection from Dampness (1) Except as permitted in Sentence (2), wood framing members that are not pressure treated with a wood preservative and which 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.
9.23.2.4. Lumber (1) Lumber shall conform to the appropriate requirements in Subsection 9.3.2.
9.23.2.5. Termite Protection (1) Where termites are known to exist, unless pressure treated with a chemical that is toxic to such termites in accordance with Article 9.3.2.9., wood steps shall rest on a non-cellulosic base or apron extending at least 150 mm above grade. (2) Wood lattice or skirting around porches shall be separated from piers and soil by at least 50 mm. 9.23.3.Fasteners
9.23.3.1. Standards for Nails and Screws (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 B18.6.1., “Slotted and Recessed Wood Screws (Inch Series)”.
9.23.3.2. Length of Nails (1) All nails shall be long enough so that not less than half their required length penetrates into the second member.
9.23.3.3. Prevention of Splitting (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.
9.23.3.4. Nailing of Framing (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 may 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 50 mm wide galvanized-metal strips (i) not less than 0.41 mm in thickness, (ii) spaced not more than 1 200 mm apart, and (iii) 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 x 140 mm or less plank decking to support

82

2


Plank decking wider than 38 mm x 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.)


Column 1

2

3 Note to Table 9.23.3.4.: (1) See Sentence 9.23.3.4.(2).
9.23.3.5.Fastening for Sheathing or Subflooring (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 Fastener


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

 


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

150 mm (o.c.) along edges and 300 mm (o.c.) along intermediate supports


Column 1

2

3

4

5

6 (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. 9.23.4.Maximum Spans
9.23.4.1. Application (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 4.1.6.3., or (b) the uniformly distributed live load on the floors do not exceed that specified for residential areas as described in Table 4.1.6.3. (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.
9.23.4.2 Spans for Joists, Rafters and Beams (1) Except as required in Sentence (2), the spans for wood joists, rafters and beams shall conform to the spans shown in Tables A-1 to A-7 for the uniform live loads shown in the tables. (2) Spans for floor joists which are not selected from Tables A-1 and A-2 and which are required to be designed for the same loading conditions, shall not exceed the design requirements for uniform loading and vibration criteria. (3) Spans for built-up wood and glued-laminated timber floor beams shall conform to the spans in Tables A-8 to A-11. (4) Spans for roof ridge beams shall conform to the spans in Table A-12 for the uniform snow load shown.
9.23.4.3. Steel Beams (1) The spans for steel floor beams with laterally supported top flanges shall conform to Table 9.23.4.3. (2) Beams described in Sentence (1) shall at least meet the requirements for Grade 300 W steel in CAN/CSA-G40.21-M, “Structural Quality Steels”. (3) A beam may be considered to be laterally supported if (a) the wood joists bear on its top flange at intervals of 610 mm or less over its entire length, (b) the load being applied to this beam is transmitted through the joists, and (c) 19 mm by 38 mm wood strips in contact with the top flange are nailed on both sides of the beam to the bottom of the joist supported. 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

4.5

4.3

4.1


W200 x 21

6.5

6.2

5.7

5.3

5.0

4.7

4.5


W200 x 27

7.3

6.9

6.6

6.3

6.1

5.8

5.5


W200 x 31

7.8

7.4

7.1

6.8

6.6

6.4

6.1


W250 x 24

8.1

7.5

6.9

6.4

6.0

5.7

5.4


W250 x 33

9.2

8.7

8.3

8.0

7.6

7.2

6.9


W250 x 39

10.0

9.4

9.0

8.6

8.3

8.9

7.6


W310 x 31

10.4

9.6

8.8

8.2

7.7

7.3

7.0


W310 x 39

11.3

10.7

10.2

9.8

9.2

8.7

8.3


Two Storeys Supported


W150 x 22

4.7

4.2

3.9

3.6

3.4

3.2

3.0


W200 x 21

5.2

4.7

4.3

4.0

3.7

3.5

3.4


W200 x 27

6.3

5.7

5.2

4.8

4.5

4.3

4.1


W200 x 31

6.9

6.2

5.7

5.3

5.0

4.7

4.5


W250 x 24

6.2

5.6

5.1

4.8

4.5

4.2

4.0


W250 x 33

7.9

7.1

6.5

6.0

5.7

5.4

5.1


W250 x 39

8.7

7.8

7.2

6.7

6.3

5.9

5.6


W310 x 31

8.0

7.2

6.6

6.1

5.8

5.4

5.2


W310 x 39

9.5

8.6

7.9

7.3

6.9

6.5

6.2


Column 1

2

3

4

5

6

7

8
9.23.4.4. Concrete Topping (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, the beam spans shown in Tables A-8 to A-11 or the supported length of the floor joists shall be reduced to allow for the loads due to the topping.
9.23.4.5. Heavy Roofing Materials (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 9.26., 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-20. 9.23.5.Notching and Drilling
9.23.5.1. Holes Drilled in Framing Members (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.
9.23.5.2. Notching of Framing Members (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.
9.23.5.3. Wall Studs (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.
9.23.5.4. Top Plates (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.
9.23.5.5. Roof Trusses (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. 9.23.6.Anchorage
9.23.6.1. Anchorage of Building Frames (1) Building frames shall be anchored to the foundation unless a structural analysis of wind and earth 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 2 400 mm 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.
9.23.6.2. Anchorage of Columns and Posts (1) Exterior columns and posts shall be anchored to resist uplift and lateral movement.
9.23.6.3. Anchorage of Smaller Buildings (1) Buildings not more than 4.3 m wide and not more than 1 storey in building height are permitted to be anchored in conformance with the requirements of CAN/CSA-Z240.10.1., “Site Preparation, Foundation and Anchorage of Mobile Homes”. 9.23.7.Sill Plates
9.23.7.1. Size of Sill Plates (1) Where sill plates provide bearing for the floor system they shall be not less than 38 mm by 89 mm material.
9.23.7.2. Levelling of Sill Plates (1) Sill plates shall be levelled by setting them on a full bed of mortar, except that where the top of the foundation is level, they may be laid directly on the foundation provided the junction between the foundation and the sill plate is caulked or the sill plate is placed on a layer of mineral wool not less than 25 mm thick before being compressed. 9.23.8.Beams to Support Floors
9.23.8.1. Bearing for Beams (1) Beams shall have even and level bearing and shall have not less than 89 mm length of bearing at end supports.
9.23.8.2. Priming of Steel Beams (1) Steel beams shall be shop primed.
9.23.8.3. Built-up Wood Beams (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 1 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 1 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 1 200 mm o.c., with the end bolts located not more than 600 mm from the ends of the members. 9.23.9.Floor Joists
9.23.9.1. End Bearing for Joists (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.
9.23.9.2. Joists Supported by Beams (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 at least 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.
9.23.9.3. Restraint of Joist Bottoms (1) Except as provided in Sentence 9.23.9.4.(5), 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.
9.23.9.4. Strapping and Bridging in Tables A-1 and A-2 (1) Where a panel-type ceiling finish is attached to wood furring, the provisions of Article 9.23.9.5. shall apply. (2) Except as permitted in Sentence (5), where strapping is specified, 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. (3) 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. (4) Where bridging and strapping are specified in Tables A-1 and A-2, they shall consist of (a) bridging as described in Sentence (3), together with, wood strapping 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, together with wood strapping as defined in Sentence (2). (5) Strapping is not required if furring strips or a panel-type ceiling finish is attached directly to the joists.
9.23.9.5. Ceiling in Table A2 (1) Where a ceiling is specified in Table A-2, it shall consist of gypsum board, plywood or OSB not less than 12.7 mm thick attached to (a) 19 mm by 89 mm wood furring spaced at not more than 600 mm o.c., or (b) 19 mm by 64 mm wood furring spaced at not more than 400 mm o.c.
9.23.9.6. Header Joists (1) Header joists around floor openings shall be doubled when they exceed 1 200 mm in length. (2) The size of header joists exceeding 3.2 m in length shall be determined by calculations.
9.23.9.7. Trimmer Joists (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 2 000 mm in length the size of the trimmer joists shall be determined by calculations.
9.23.9.8. Support of Tail and Header Joists (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.
9.23.9.9. Support of Walls (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 1 200 mm 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 design loads to 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.
9.23.9.10. Cantilevered Floor Joists (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 (a) extend inward away from the cantilever support a distance equal to not less than 6 times the length of the cantilever, and (b) shall be end nailed to an interior doubled header joist in conformance with Table 9.23.3.4. 9.23.10.Wall Stud
9.23.10.1. Stud Size and Spacing (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


 

38 x 64

600

3.0


 

38 x 64 flat(1)

400

2.4


Attic not accessible by a stairway

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

38 x 89

400

3.6


Attic not accessible by stairway plus 2 floors

 

 

 


Roof load

38 x 64

400

2.4


Attic accessible by a stairway

38 x 89

600

3.6


Attic not accessible by a stairway plus one floor

 

 

 


Attic accessible by a stairway plus 2 floors

38 x 89

300

3.6


Roof load plus 2 floors

64 x 89

400

3.6


 

38 x 140

400

4.2


Attic accessible by a stairway plus 3 floors

38 x 140

300

4.2


Roof load plus 3 floors

 

 

 


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


 

38 x 89

300

3.0


Roof with or without attic storage plus 2 floors

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


Column 1

2

3

4

5 Note to Table 9.23.10.1.: (1) See Article 9.23.10.3.
9.23.10.2. Bracing and Lateral Support (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 the 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 x 89 mm wood members, (b) be applied to the studs at an angle of approximately 45o 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 mid-height to prevent sideways buckling.
9.23.10.3. Orientation of Studs (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 1 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 2 100 mm in width.
9.23.10.4. Continuity of Studs (1) Wall studs shall be continuous for the full storey height except at openings and shall not be spliced except by finger-jointing with a structural adhesive.
9.23.10.5. Support for Cladding Materials (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.
9.23.10.6. Studs at Sides of Openings (1) Except as provided in Sentence (2), studs shall be doubled on each side of openings so that the inner studs extend from the lintel to the bottom wall plate and the outer studs extend from the top wall plates to the bottom wall plate. (2) 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. 9.23.11.Wall Plates
9.23.11.1. Size of Wall Plates (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 may be 19 mm thick.
9.23.11.2. Bottom Wall Plates (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.
9.23.11.3. Top Plates (1) Except as permitted in Sentences (2) to (4), no fewer than 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 (a) not less than 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.
9.23.11.4. Joints in Top Plates (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 suitably 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. 9.23.12.Framing Over Openings
9.23.12.1. Openings in Non-Loadbearing Walls (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.
9.23.12.2. Openings in Loadbearing Walls (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. (2) Except as provided in Sentence 9.23.12.3.(3), 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 may be separated by filler pieces.
9.23.12.3. Lintel Spans and Sizes (1) Spans and sizes of wood lintels shall conform to the spans shown in Tables A-13 to A-20 (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 x 64 mm framing members, lintels shall consist of (a) solid 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-13 to A-20 for the maximum spans shown, and (b) shall not exceed 2 240 mm in length. 9.23.13.Roof and Ceiling Framing
9.23.13.1. Continuity of Rafters and Joists (1) Roof rafters and joists and ceiling joists shall be continuous or shall be spliced over vertical supports that extend to suitable bearing.
9.23.13.2. Framing around Openings (1) Roof and ceiling framing members shall be doubled on each side of openings greater than 2 rafter or joist spacings wide.
9.23.13.3. End Bearing Length (1) The length of end bearing of joists and rafters shall be not less than 38 mm.
9.23.13.4. Location and Attachment of Rafters (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 1 200 mm apart and nailed at each end to the framing by at least two 63 mm nails.
9.23.13.5. Shaping of Rafters (1) Rafters shall be shaped at supports to provide even bearing surfaces and supported directly above the exterior walls.
9.23.13.6. Hip and Valley Rafters (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.
9.23.13.7. Intermediate Support for Rafters and Joists (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 2 400 mm 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 may 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.
9.23.13.8. Ridge Support (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 x 140 mm material, and (b) the beam is supported at intervals not exceeding 1 200 mm 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. (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 the 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. 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 75 mm Long


Rafter Tied to every Joist

Rafter tied to Joist every 1.2 m


Building Width 

Building Width 

Building Width 

Building Width 


up to 8 m

up to 9.8 m

up to 8 m

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


Column 1

2

3

4

5

6

7

8

9

10

11

12

13

14
9.23.13.9. Restraint of Joist Bottoms (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.
9.23.13.10. Ceiling Loads Supporting Roof Loads (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.
9.23.13.11. Wood Roof Trusses (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 0.5 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


Column 1

2

3 (2) The joint connections used in trusses described in Sentence (1) shall be designed in conformance with the requirements in Subsection 4.3.1. (3) Where the length of compression web members in roof trusses described in Sentence (1) exceeds 1 830 mm, 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 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. 9.23.14.Subflooring
9.23.14.1. Subflooring Required (1) Subflooring shall be provided beneath finish flooring where the finish flooring does not have adequate strength to support the design loads.
9.23.14.2. Material Standards (1) Wood-based panels for subfloors shall conform to (a) CSA O121, “Douglas Fir Plywood”, (b) CSA O151, “Canadian Softwood Plywood”, (c) CSA O153, “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 N-1 or N-2 in CAN3-O188.1, “Interior Mat-Formed Wood Particleboard”. (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 and other areas subject to periodic wetting.
9.23.14.3. Edge Support (1) Where the edges of panel-type subflooring are required to be supported, 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.
9.23.14.4. Direction of Installation (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 O-1 and O-2 grades in CSA-O437.0 and waferboard subflooring conforming to R-1 grade in CSA O437.0 shall be installed with the direction of face orientation at right angles to the joists and with the joints parallel to floor joists staggered.
9.23.14.5. Subfloor Thickness or Rating (1) Except as provided in Sentences (2) and (3), subfloors shall conform to 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 9.23.15.6.(1)  Maximum Spacing 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


Column 1

2

3

4

5 Table 9.23.14.5.B. Rating for Subfloor when Applying CSA O325.0 Forming Part of Sentences 9.23.14.5.(1) and 9.23.15.6.(1)  Maximum Spacing of Supports, mm

Panel Mark


Subfloor

Used with Panel-Type Underlay


400

1F16

2F16


500

1F20

2F20


600

1F24

2F24


Column 1

2

3 (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, or (d) 12.7 mm thick waferboard conforming to R-1 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 may 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, or (d) 12.7 mm thick waferboard conforming to R-1 grade.
9.23.14.6. Annular Grooved Nails  (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.
9.23.14.7. Lumber Subflooring (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. 9.23.15.Roof Sheathing
9.23.15.1. Material Standards (1) Wood-based panels used for roof sheathing shall conform to the requirements of (a) CSA O121, “Douglas Fir Plywood”, (b) CSA O151, “Canadian Softwood Plywood”, (c) CSA O153, “Poplar Plywood”, (d) CAN/CSA-O325.0, “Construction Sheathing”, or (e) CAN3-O437.0, “OSB and Waferboard”.
9.23.15.2. Direction of Installation (1) Plywood roof sheathing shall be installed with the surface grain at right angles to the roof framing. (2) OSB roof sheathing conforming 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.
9.23.15.3. Joints in Panel Type Sheathing (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.
9.23.15.4. Lumber Roof Sheathing (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.