The Ontario Building Code | Openings in Fire Separations
9.24.2.4. openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings in Fire Separations
(1) Where openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings for doors in non-loadbearing fire separations required to have a fire-resistance rating do not exceed 1.2 m in width,
(a) the width of steel studs shall be not less than 63 mm, and
(b) the steel thickness shall be not less than 0.46 mm.
(2) Where openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings described in Sentence (1) exceed 1.2 m in width,
(a) the width of steel studs shall be not less than 91 mm, and
(b) the metal thickness shall be not less than 0.85 mm.
(3) The distance to the first stud beyond the jamb of any door opening in a fire separation required to have a fire-resistance rating shall not exceed 400 mm.
(4) Where the distance between the framing over the opening referred to in Sentence (3) and the top runner exceeds 400 mm in such walls, intermediate support shall be installed at intervals of not more than 400 mm above the opening.