COMBUSTIBLE MATERIALS PERMITTED IN A NONCOMBUSTIBLE CONSTRUCTION
(1) Combustible elements permitted in roofs, floors and walls: The combustible element of roofs, floors and walls shall be limited to:
(a) the following minor components:
i. paint;
ii. tightly adhering paper covering not more than 1 mm thick applied to a noncombustible backing provided the assembly has a flame spread rating of 25 or less;
iii. combustibles incidental to insulated wiring;
iv. mastics and caulking materials applied to provide flexible seals between the components of exterior wall construction;
v. wood furring strips not exceeding 50 mm × 50 mm nominal dimension attached directly to a continuous noncombustible backing, or wood nailing strips set into continuous noncombustible backing, for the attachment of interior finishes; and
vi. approved secondary elements having characteristics similar to the above-mentioned items;
(b) roof covering materials;
(c) adhesives and vapour barriers having a flame spread rating of 25 or less; and
(d) insulation, other than foamed plastics, having a flame-spread rating of not more than 25 on any exposed surface or any surface that would be exposed by cutting through the material in any direction;
(e) foamed plastic insulation with a flame spread rating of not more than 25 on any exposed surface or any surface that would be exposed by cutting through the material in any direction, on condition that it is protected by one of the following:
i. gypsum-board at least 12.7 mm thick attached with fasteners to the supporting assembly independent of the insulation;
ii. lath and plaster, attached with fasteners to the supporting assembly independent of the insulation;
iii. masonry;
iv. concrete;
v. any thermal barrier that will not exceed an average temperature rise of 139º C when it is subject for 10 minutes to a test in accordance with the ULC S101-1977, Standard Methods of Fire Endurance Tests of Building Construction and Materials;
(f) insulation, including foamed plastics, having a flame-spread rating of greater than 25 but not greater than 500 on any exposed surface or any surface that would be exposed by cutting through the material in any direction provided the insulation is protected with a thermal barrier as described in paragraph e. However, in the very high buildings described in section 19 not equipped with sprinkler systems, this insulation must be protected by one of the following:
i. at least 2 layers of 15.9 mm thick type X special fire resistant gypsum board, conforming to CAS A82.27-M 1977, Gypsum Board Products, with at least the first layer mechanically fastened to the supporting assembly independent of the insulation;
ii. at least 75 mm of masonry or concrete;
iii. any thermal barrier that when tested in conformance with ULC S101-1977, Standard Methods of Fire Endurance Tests of Building Construction and Materials, will not exceed an average temperature rise of 130 ºC on the unexposed face of the thermal barrier after a period of 45 minutes;
(g) insulation, including foamed plastic installed above roof decks, outside of foundation walls below ground level and beneath concrete slabs-on-ground;
(h) combustible skylights:
i. if their surface does not exceed 9 m2 with a maximum dimension of 3 m;
ii. if they are spaced at least 2.5 m apart and at least 2.5 m from the required fire separations;
iii. if their total surface is not greater than 10% of the ceiling area of the room in which they are located; and
iv. if their flame-spread rating does not exceed 250 under the test conditions of standard ULC-S102-2-1973, Standard Method of Test for Surface Burning Characteristics of Flooring, Floor Covering and Miscellaneous Materials;
(i) the wood used for building false roofs on a concrete slab or on steel bridging offering the prescribed fire-resistance provided that:
i. (subparagraph revoked);
ii. the space included between this slab and false roof does not have an average height of more than 1 m and is divided by fire separations forming compartments of equal volume not over 300 m2 of surface without any one of their dimensions being over 45 m;
iii. each compartment over 1 m in height must be equipped with at least one thermic detector connected to the alarm system;
iv. any stairway, stairwell or stairshaft except for plumbing conduits made of noncombustible materials crossing this space must be separated along its entire height by masonry or concrete elements having the same degree of fire-resistance as the roof slab;
v. any opening in the slab giving access to the space above the latter shall be protected by closures with a fire-resistance rating in accordance with Table 2 of Schedule B;
vi. any cornice or projection beyond a wall at roof level shall be of noncombustible material.
(2) Millwork, interior cladding and finishing materials: Combustible millwork, interior cladding and finishing materials shall be limited to:
(a) millwork, such as interior trim, ordinary doors and door frames, show windows together with their frames, aprons and backing;
(b) window sash and frames provided:
i. each window in an exterior wall face is an individual unit separated by noncombustible wall construction from every other opening in the wall;
ii. windows in exterior walls in contiguous storeys are separated by at least 900 mm of noncombustible construction; and
iii. the aggregate area of openings in an exterior wall face of a fire compartment does not exceed 40% of the area of the wall face;
(c) finished flooring applied directly to a floor slab in which wood nailing strips may be incorporated or applied to wood sleepers on top of a floor slab, provided the space between the flooring is fire stopped;
(d) interior finishes such as paint, wallpaper and other interior finishes not more than 1 mm thick;
(e) interior wall finishes that:
i. are not more than 25 mm thick; and
ii. have a flame spread rating of not more than 150 on any exposed surface, or any surface that would be exposed by cutting through the material in any direction; and
(f) interior ceiling finishes that:
i. are not more than 25 mm thick; and
ii. have a flame spread rating of not more than 25 on any exposed surface or on any surface that would be exposed by cutting through the material in any direction.
(3) Combustible ducts: Combustible ducts shall be limited to rigid or flexible ducts having a flame spread rating of not more than 25 on any exposed surface or on any that would be exposed by cutting through the material in any direction, and a smoke developed classification of not more than 50 provided such ducts:
(a) are used only in horizontal runs;
(b) do not pass through a fire separation, stipulated by this Regulation;
(c) do not exceed 130 cm2 in cross-sectional area and 4.3 m in length unless the ducts are installed in an assembly required to have a fire resistance rating, and the complete assembly including ducts has been tested to determine fire resistance rating; and
(d) conform to UL No. 181 (1967) Air Ducts for Class 1.
(4) Garage floor: The finish of a garage floor may be of an asphalt compound.
(5) Partitions of combustible construction:
(1) Dwellings in an apartment house may have partitions of combustible construction made of wood studs covered on both sides of noncombustible cladding or gypsum wallboard, except that such cladding or wallboard may be covered with paint or tightly adhering paper not exceeding 1 mm in thickness.
(2) Office buildings and stores may have partitions of combustible construction if they are not required to act as fire separations:
(a) where the floor area is protected by automatic sprinkler systems; or
(b) within spaces having an area of not more than 500 m2 where such spaces are separated from the remainder of the floor area by at least fire separations of noncombustible construction with a fire-resistance rating of at least 1 hour.
Partitions of combustible construction shall be limited to:
(a) that referred to in subsection 1;
(b) wood studs covered on both sides by fire-retardant treated wood having a flame-spread rating of not more than 25;
(c) glass in wood sash; or
(d) solid lumber not less than 38 mm thick.