PART 9 — HOUSING AND SMALL BUILDINGSUpdated for the 2024 Ontario Building Code
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9.23.3.5.Fastening for Sheathing or Subflooring
(1) Except as required by Sentences (2) to (4), fastening of sheathing and subflooring shall conform to Table 9.23.3.5.-
A.
Table 9.23.3.5.-A
Fasteners for Subflooring and for Sheathing where the 1-in-50 HWP < 0.8 kPa and Sa(0.2) ≤ 0.70
Forming Part of Sentence 9.23.3.5.(1)
Minimum Length of Fasteners, mm
Minimum Number or
Element Ring Thread Maximum Spacing of
Common or Roofing
Nails or Staples Fasteners
Spiral Nails Nails
Screws
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
150 mm o.c. along
Plywood, OSB or waferboard up to 10 mm thick 51 45 n/a 38
edges and
Plywood, OSB or waferboard over 10 mm and up to 300 mm o.c. along
51 45 n/a 51
20 mm thick intermediate supports
Plywood, OSB or waferboard over 20 mm and up to
57 51 n/a n/a
25 mm thick
(2) Fastening of roof sheathing and sheathing in required braced wall panels shall conform to Table 9.23.3.5.-B, where
(a) the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.8 kPa and less than 1.2 kPa and the seismic
spectral acceleration, Sa(0.2), is not more than 0.90, or
(b) the seismic spectral acceleration, Sa(0.2), is greater than 0.70 and not more than 0.90.
(3) Fastening of roof sheathing and sheathing in required braced wall panels shall conform to Table 9.23.3.5.-C, where
(a) the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.8 kPa and less than 1.2 kPa and the spectral
acceleration, Sa(0.2), is not more than 1.8, or
(b) the seismic spectral acceleration, Sa(0.2), is greater than 0.90 and not more than 1.8.
(4) Fastening of sheathing shall conform to Part 4,
(a) where the 1-in-50 hourly wind pressure is equal to or greater than 1.2 kPa, or
(b) for required braced wall panels, where the seismic spectral acceleration, Sa(0.2), is greater than 1.8.
(5) Staples shall not be less than 1.6 mm in diameter or thickness, with not less than a 9.5 mm crown driven with the
crown parallel to framing.
Table 9.23.3.5.-B
Fasteners for Sheathing where 0.8 kPa ≤ 1-in-50 HWP < 1.2 kPa and Sa(0.2) ≤ 0.90 or where 0.70 < Sa(0.2) ≤ 0.90
Forming Part of Sentence 9.23.3.5.(2)
Minimum Length of Fasteners, mm
Common, Minimum Number or Maximum Spacing
Element 14-gauge
Spiral or Ring Screws of Fasteners
Staples
Thread Nails
Board lumber 184 mm or less wide 63 51 63 2 per support
Board lumber more than 184 mm wide 63 51 63 3 per support
Plywood, OSB or waferboard up to 150 mm o.c. along edges and 300 mm o.c. along
63 51 63
20 mm thick(1) intermediate supports; and for roof sheathing
where HWP is equal to or greater than 0.8 kPa
Plywood, OSB or waferboard over and less than 1.2 kPa, 50 mm o.c. within 1 m of
63 57 n/a
20 mm and up to 25 mm thick the edges of the roof
Notes to Table 9.23.3.5.-B:
(1) See Note A-Table 9.23.3.5.-B.
Table 9.23.3.5.-C
Fasteners for Sheathing where 0.8 kPa ≤ 1-in-50 HWP < 1.2 kPa and Sa(0.2) ≤ 1.8 or where 0.90 < Sa(0.2) ≤ 1.8
Forming Part of Sentence 9.23.3.5.(3)
Minimum Length of Fasteners,
mm
Element Common, Minimum Number or Maximum Spacing of Fasteners
Spiral or Ring Screws
Thread Nails
Plywood, OSB or waferboard up to 75 mm o.c. along edges and 300 mm o.c. along intermediate
63 51
20 mm thick(1) supports; and for roof sheathing where 1-in-50 HWP is equal
Plywood, OSB or waferboard over to or greater than 0.8 kPa and less than 1.2 kPa, 50 mm o.c.
63 57 within 1 m of the edges of the roof
20 mm and up to 25 mm thick
Notes to Table 9.23.3.5.-C:
(1) See Note A-Table 9.23.3.5.-B.
(6) Roofing nails for the attachment of fibreboard or gypsum sheathing shall not be less than 3.2 mm in diameter with a
minimum head diameter of 11.1 mm.
(7) Flooring screws shall not be less than 3.2 mm in diameter.
(7.1) Where roof sheathing supports are spaced at more than 400 mm o.c., the maximum spacing of fasteners for roof
sheathing shall be 150 mm along edges and intermediate supports.
(8) The edges of sheathing in a braced wall panel shall be supported and fastened to wood blocking where
(a) the seismic spectral acceleration, Sa(0.2), is greater than 1.2, or
(b) the braced wall panel supports more than a roof of lightweight construction.
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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.