18. Flame spread:
(1) Coating materials for interior finishing that are an integral part of the surface of a wall or a ceiling in an assembly occupancy must have a flame spread rating of not more than 150. This rating is the same for partitions or movable screens.
(2) Wall hangings, curtains and decorative materials made out of textiles and used in:
(a) an assembly occupancy or a hospital or special care institution;
(b) a corridor or an exit;
(c) a floor area without partitions of more than 500 m2 used as an office, except if this floor is divided into compartments of not more than 500 m2 separated by fire separations whose fire-resistance rating is at least 3/4 of an hour;
shall have the degree of flame-resistance corresponding to the test method 27.1 of the Standard CAN 2-4.2-M77, Canadian Standard for Textile Test Methods.
(3) Decorations made of resinous trees such as fir, pine or spruce or branches from such trees, of nitrocellulose or crepe paper, except if the latter meets the requirements of ULC-S109-1969 Standard for Flame Tests, Flame-Resistant Fabrics and Films, may not be used in an assembly occupancy, hotel or a hospital or special care institution.
Subsections 2 and 3 do not apply to places of worship.
(4) Subject to subsections 5 and 6, the flame spread rating of the walls and ceilings of an exit shall be a maximum of 25.
(5) The interior finish of inside walls and ceilings in exits may have a flame spread rating not exceeding 150 on condition that their area does not exceed 10% of the area of the walls and ceiling, if such is the case.
(5.1) Inside the building, the interior finish of the walls and ceilings shall, in stairways used as an exit, in public corridors and in sleeping or common activity areas in a family-type building, have a flame spread rating not exceeding 150.
(6) The wall finish in a lobby used as an exit may have a maximum flame spread rating of 150 over a maximum 25% of the wall surface.
(7) Except for a floor over a crawl space, the floor of a storey shall be constructed as a fire separation. Any opening in such floor without a closing device shall be surrounded by a fire separation having a fire-resistance rating of a least 3/4 of an hour.
However, an opening need not be separated by a fire separation in the following cases:
(a) for a stairway linking the ground floor with the storey above or below but not both, provided that the stairway is not used as a required exit, except in the case provided for in paragraph b of subsection 2 of section 20;
(b) for a vehicular ramp between garage levels;
(c) to link a maximum of 2 floor areas equipped with automatic sprinklers, and not used for sleeping accommodation; and
(d) to link more than 2 stories in a building of noncombustible construction, provided that:
i. each floor area giving access to the opening is equipped with automatic sprinklers installed in conformity with NFPA Standard 13-1974, “Installation of Sprinkler Systems”; with combustion by-product detectors; with vent shafts; and with a smoke retaining screen;
ii. floor areas situated above the opening are equipped with exits that the occupants of the upper stories can reach without having to cross the areas leading to the openings; and
iii. 50% of all exits of upper stories lead directly to the outside, without access to the stories leading to the opening, unless the exits of these stories may be reached by crossing a vestibule separated from the floor area by a fire separation with a fire-resistance rating of 3/4 of an hour.
(8) Foamed plastic applied to the outside surface of a wall or on a ceiling shall be covered with an interior finish. The finish shall comply with Schedule D, for a building of noncombustible construction; and with Division 9.28 of the Building Code (R.R.Q., 1981, c. S-3, r. 2), for a building of combustible construction.