The Ontario Building Code | Spacing of Nails
9.29.5.8. Spacing of Nails
(1) For single-layer application on ceilings, nails shall be spaced,
(a) not more than 180 mm o.c. on ceiling supports, or
(b) every 300 mm o.c. along ceiling supports, in pairs about 50 mm apart.
(2) Where the ceiling sheets are supported by the wall sheets around the perimeter of the ceiling, this support may be considered as equivalent to nailing at this location.
(3) Except as required by Sentence (4), for single-layer application on walls, nails shall be spaced,
(a) not more than 200 mm o.c. on vertical wall supports, or
(b) every 300 mm o.c. along vertical wall supports, in pairs about 50 mm apart.
(4) For single-layer application on walls, where gypsum board is required to provide bracing, lateral support or fire protection, nails shall be spaced not more than 200 mm o.c. on,
(a) vertical wall supports, and
(b) top and bottom plates.
(5) The uppermost nails on vertical wall supports shall be not more than 200 mm below the ceiling.
(6) Nails shall be located not less than 10 mm from the side or edge of the board.
(7) Nails shall be driven so that the heads do not puncture the paper.