9.10.17.

(1) Except as otherwise provided in this Subsection, the exposed surface of every interior wall and ceiling, including skylights and glazing, shall have a surface flame-spread rating of not more than 150.

(2) Except as permitted in Sentence (3), doors need not conform to Sentence (1) provided they have a surface flame-spread rating of not more than 200.

(3) Doors within dwelling units, other than vehicle garage doors, need not conform to Sentences (1) and (2).

(1) At least 90% of the exposed surface of every ceiling in an exit or unsprinklered ceiling in a public corridor shall have a surface flame-spread rating of not more than 25.

(1) Except as provided in Sentence (2), at least 90% of the exposed surfaces of every wall in an exit shall have a surface flame-spread rating of not more than 25.

(2) At least 75% of the wall surface of a lobby used as an exit in Article 9.9.8.5. shall have a surface flame-spread rating of not more than 25.

(1) Where an exterior exit passageway provides the only means of egress from the rooms or suites it serves, the wall and ceiling finishes of that passageway, including the soffit beneath and the guard on the passageway, shall have a surface flame-spread rating of not more than 25, except that up to 10% of the total wall area and 10% of the total ceiling area is permitted to have a surface flame-spread rating of not more than 150.

(1) At least 90% of the total wall surface in any unsprinklered public corridor shall have a surface flame-spread rating of not more than 75, or at least 90% of the upper half of such walls shall have a surface flame-spread rating of not more than 25.

(1) Skylights, glazing, combustible doors, and combustible light diffusers and lenses shall not be considered in the calculation of wall and ceiling areas in this Subsection.

(1) Where a public corridor or a corridor used by the public contains an occupancy, the interior finish materials used on the walls or ceiling of such occupancy shall have a surface flame-spread rating in conformance with that required for public corridors.

(1) Light diffusers and lenses having flame-spread ratings that exceed those permitted for the ceiling finish, shall conform to the requirements of Sentence 3.1.13.4.(1).

(1) Individual combustible skylights in corridors required to be separated from the remainder of the building by fire separations shall not exceed 1 m² in area and shall be spaced not less than 1 200 mm apart.

(1) Except as provided in Sentence (2), foamed plastics that form part of a wall or ceiling assembly in combustible construction shall be protected from adjacent space in the building other than adjacent concealed spaces within attic or roof spaces, crawl spaces, and wall assemblies, by,

(a) one of the finishes described in Subsections 9.29.4. to 9.29.9.,

(b) sheet metal mechanically fastened to the supporting assembly independent of the insulation and having a thickness of not less than 0.38 mm and a melting point not below 650°C provided the building does not contain a Group C major occupancy, or

(c) any thermal barrier that meets the requirements of Clause 3.1.5.11.(2)(e).

(2) Foamed plastic insulation having a flame-spread rating of not more than 500 is permitted to be used in factory-assembled doors in storage garages serving buildings of residential occupancy provided that,

(a) the insulation is covered on the interior with a metallic foil,

(b) the assembly has a surface flame-spread rating of not more than 200, and

(c) the assembly incorporates no air spaces.

(1) The interior finish of walls and ceilings in bathrooms within suites of residential occupancy shall have a surface flame-spread rating of not more than 200.

(1) Where a covering or a lining is used with a duct, such lining or covering shall have a flame-spread rating conforming to Part 6.