(1)
Except as provided in Sentences (2) and (3), the floor assembly of every exterior passageway used as part of a means of egress shall have a fire-resistance rating of not less than 45 min or be of noncombustible construction.
(2)
No fire-resistance rating is required for floors of exterior passageways serving buildings of Group D, E or F major occupancy that are not more than 2 storeys in building height.
(3)
No fire-resistance rating is required for floors of exterior passageways serving
(a)
a house with a secondary suite, or
(b)
a single dwelling unit where no suite is located above or below the dwelling unit. (See also Sentence 9.9.9.3.(2))