3.4.4.4 — Integrity of Exits

(1) Except as permitted by Articles 3.1.8.16. and 3.1.8.17. for the separation of exits, an opening in a fire separation having a fire-resistance rating not more than 1 h is permitted to be protected with fixed wired glass assemblies or glass blocks installed in conformance with NFPA 80, “Fire Doors and Other Opening Protectives”. (2) Wired glass assemblies permitted by Sentence (1) and described in MMAH Supplementary Standard SB-2, “Fire Performance Ratings”, are permitted to be used as closures in vertical fire separations without being tested in accordance with Sentence 3.1.8.4. (1). (3) Glass blocks permitted by Sentence (1) shall be installed in accordance with Subsection 4.3.2. and reinforced with steel reinforcement in each horizontal joint.

(1) A sprinkler protected glazed wall assembly shall be constructed in accordance with the requirements of ULC/ORD C263.1, “Sprinkler-Protected Windows Systems”. (2) A sprinkler protected glazed wall assembly shall not be installed in, (a) fire separations requiring a fire-resistance rating of more than two hours, (b) a firewall, (c) a high hazard industrial occupancy, or (d) any part of an exit serving, (i) a floor area subject to the requirements of Subsection 3.2.6., (ii) a care occupancy, (iii) a care and treatment occupancy, (iv) a detention occupancy, or (v) a residential occupancy. (3) Where a sprinkler protected glazed wall assembly is installed in an exit fire separation permitted in Sentence (2), (a) the building shall be sprinklered, and (b) the exits protected with the sprinkler protected glazed wall assemblies shall not comprise more than one-half of the required number of exits from any floor area.

(1) A rooftop enclosure provided for elevator machinery, a stairway or a service room used for no purpose other than for service to the building, shall not be considered as a storey in calculating the building height. (2) Space under tiers of seats in a building of the arena type shall not be considered as adding to the building height provided the space is used only for dressing rooms, concession stands and similar purposes incidental to the major occupancy of the building. (3) Except as required by Sentence (5), the space above a mezzanine need not be considered as a storey in calculating building height provided, (a) the aggregate area of mezzanines that are not superimposed does not exceed 40% of the open area of the room in which they are located, and (b) except as permitted in Sentence (8) and Sentence 3.3.2.11. (3) the space above the mezzanine is used as an open area without partitions or subdividing walls higher than 1 070 mm above the mezzanine floor. (4) Except as required by Sentence (5), the space above a mezzanine need not be considered as a storey in calculating the building height provided, (a) the aggregate area of mezzanines that are not superimposed and do not meet the conditions of Sentence (3) does not exceed 10% of the floor area in which they are located, and (b) the area of mezzanine in a suite does not exceed 10% of the area of that suite. (5) Except as permitted by Sentences (6) and (7), each level of mezzanine that is partly or wholly superimposed above the first level of mezzanine shall be considered as a storey in calculating the building height. (6) Platforms intended solely for periodic inspection and elevated catwalks need not be considered as floor assemblies or mezzanines for the purpose of determining building height provided, (a) they are not used for storage, (b) they are constructed with noncombustible materials unless the building is permitted to be of combustible construction, and (c) where they are intended to be occupied, they have an occupant load of not more than four persons. (7) Mezzanines, elevated walkways and platforms that are intended to be occupied in Group F, Division 2 or 3 major occupancies need not be considered as storeys in calculating building height provided, (a) the building is of noncombustible construction, and (b) the occupant load is not more than four persons. (8) The space above a mezzanine conforming to Sentence (3) is permitted to include an enclosed space whose area does not exceed 10% of the open area of the room in which the mezzanine is located, provided the enclosed space does not obstruct visual communication between the open space above the mezzanine and the room in which it is located. (9) A service space in which facilities are included to permit a person to enter and to undertake maintenance and other operations pertaining to building services from within the service space need not be considered a storey if it conforms to Articles 3.2.5.15. and 3.3.1.23. and Sentences 3.2.4.20. (12), 3.2.7.3. (2), 3.3.1.3. (7), 3.4.2.4. (3) and 3.4.4.4. (9).