(1) Except as permitted by Sentences (2) and (3), in a building of residential occupancy, a laundry room in a floor area that is not within a dwelling unit shall be separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 1 h.
(2) The fire-resistance rating of the fire separation required by Sentence (1) is permitted to be not less than 45 min provided the fire-resistance rating required by Subsection 3.2.2. is permitted to be less than 1 h for,
(a) the floor assembly above the floor area, or
(b) the floor assembly below the floor area, if there is no floor assembly above.
(3) The fire separation required by Sentence (1) is not required to have a fire-resistance rating if the floor area in which the laundry room is located is sprinklered.