General notes

The foregoing review has covered the rules governing the location, size and detail of the stairs themselves. Very specific rules also govern the sizes of the corridors or aisles leading to the stairs, the doors that open into the stairways and the doors that exit from them.

Aisles and corridors

An aisle (as in a department store for example) or corridor leading to any stair must be at least wide enough to match the capacity of the stair it serves.

Doors

Stair access doors must open in the direction of travel, i.e. into the stair enclosure. When doors are fully open they may intrude into the landing space no more than 7 in (178 mm).

Doors must be self-closing, be unlocked but equipped with a latch that will open automatically under pressure, and have a fire rating matching that of the enclosure. Doors exiting from stairs must be equipped with panic hardware. All doors, in or out, must be a minimum width of 32 in (813 mm) and match the capacity of the stair.

Stair enclosures

All stairs required as a legal means of egress must be constructed of non-combustible materials and must be within a fire-rated enclosure. For buildings of more than four floors the rating is generally 2 hours; 1 hour if less. A 2-hour fire rating can be achieved with an assembly comprising 6 in (152 mm) galvanized metal studs with two layers of 5/8 in (16 mm) 'fire code' gypsum board (equal to Fireline board) on each side.

Lighting

All stairs must be equipped with an emergency lighting system. In smaller buildings the system may be energized by battery packs; in large buildings, such as hospitals and department stores, a generator set that kicks in immediately upon the failure of electrical service, is required.

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