7.2.2.2.3 Spiral Stairs.

7.2.2.2.3.1 Where specifically permitted for individual occupancies by Chapters 11 through 43, spiral stairs shall be permitted as a component in a means of egress in accordance with 7.2.2.2.3.2 through 7.2.2.2.3.4.

7.2.2.2.3.2 Spiral stairs shall be permitted, provided that all of the following criteria are met:

(1) Riser heights shall not exceed 7 in. (180 mm).

(2) The stairway shall have a tread depth of not less than 11 in. (280 mm) for a portion of the stairway width sufficient to provide egress capacity for the occupant load served in accordance with 7.3.3.1.

(3) At the outer side of the stairway, an additional 101∕2 in. (265 mm) of width shall be provided clear to the other handrail, and this width shall not be included as part of the required egress capacity.

(4) Handrails complying with 7.2.2.4 shall be provided on both sides of the spiral stairway.

(5) The inner handrail shall be located within 24 in. (610 mm), measured horizontally, of the point where a tread depth of not less than 11 in. (280 mm) is provided.

(6) The turn of the stairway shall be such that the outer handrail is at the right side of descending users.

7.2.2.2.3.3 Where the occupant load served does not exceed three, spiral stairs shall be permitted, provided that all of the following criteria are met:

(1) The clear width of the stairs shall be not less than 26 in. (660 mm).

(2) The height of risers shall not exceed 91∕2 in. (240 mm).

(3) The headroom shall be not less than 6 ft 6 in. (1980 mm).

(4) Treads shall have a depth not less than 71∕2 in. (190 mm) at a point 12 in. (305 mm) from the narrower edge.

(5) All treads shall be identical.

(6) Handrails shall be provided on both sides of the stairway.

7.2.2.2.3.4 Where the occupant load served does not exceed five, existing spiral stairs shall be permitted, provided that the requirements of 7.2.2.2.3.3(1) through 7.2.2.2.3.3(5) are met.

Referring to 101-Table 7.2.8.4(b), Spiral Stair is permitted for/as "replacement fire escape stairs" if "serving 10 or fewer occupants"

12.2.2.3.2.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted in means of egress from lighting and access catwalks,galleries, and gridirons.

13.2.2.3.2.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted in means of egress from lighting and access catwalks,galleries, and gridirons.

20.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (New Ambulatory Health CareOccupancies)

21.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (Existing Ambulatory Health CareOccupancies)

22.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted for access to and between staff locations. (New Detention and CorrectionalOccupancies)

23.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted for access to and between staff locations. (Existing Detention and CorrectionalOccupancies)

24.2.5.5 Spiral stairs and winders in accordance with 7.2.2.2.3and 7.2.2.2.4 shall be permitted within a single dwelling unit. (One- and Two-Family Dwellings)

30.2.2.3.3 Spiral stairs complying with 7.2.2.2.3 shall be permitted within each dwelling unit. (New Apartment Buildings)

31.2.2.3.3 Spiral stairs complying with 7.2.2.2.3 shall be permitted within a single dwelling unit. (Existing Apartment Buildings)

36.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (New Mercantile Occupancies)

37.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (Existing Mercantile Occupancies)

38.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (New Business Occupancies)

39.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (Existing Business Occupancies)

40.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (Industrial Occupancies)

42.2.2.3.2 Spiral stairs complying with 7.2.2.2.3 shall be permitted. (Storage Occupancies)