SECTION 1011 – STAIRWAYS

1011.5.5  Modify the first sentence of the first paragraph as follows:

   For all occupancies except R-3 one and two family dwellings and townhouses nosings shall have a curvature or bevel of not less than 1/16 (1.6 mm) but not more than 9/16 (14.3 mm) from the foremost projection of the tread. Risers shall be solid and vertical or sloped under the tread above from the underside of the nosing above at an angle not more than 30 degree (0.52 rad) from the vertical.

1011.5.5  Add a second paragraph as follows:

   For R-3 one and two family dwellings and townhouses, the radius of curvature at the nosing shall be no greater than 9/16 inch (14mm). A nosing not less than 3/4 inch (19 mm) but not more than 1-1/4 inches (32 mm) shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than 3/8 inch (9.5 mm) between two stories, including the nosing at the level of floors and landings. Beveling of nosings shall not exceed 1/2 inch (12.7 mm).

   Exception:  A nosing projection is not required where the tread depth is no less than 11 inches (279 mm). [CRC R311.7.5.3]

1011.5.5.1  Modify the first sentence of the first paragraph as follows:

For all occupancies except R-3 one and two family dwellings and townhouses the leading edge (nosings) of treads shall project not more than 1¼ inches (32 mm) beyond the tread below.

1011.12  Add a sentence to the end of the Exception as follows:

   Exception: Other than where required by Section 1011.12.1, in buildings without an occupied roof access to the roof from the top story shall be permitted to be by an alternating tread device, a ships ladder or a permanent ladder. Stairs or ladders used only to attend equipment or window wells are exempt from the requirements of this chapter.

(Amended by Ord. 65-19, File No. 190136, App. 4/12/2019, Eff. 5/13/2019)

1011.12.3  Add new sections as follows:

1011.12.3  Stairway replacement.  Stairways that replace existing stairways in residential occupancies and which complied with the code in effect at the time they were constructed, and which have been adequately maintained and increased in relation to any increase in occupant load, alteration or addition, or any change in occupancy, may be reconstructed in the same configuration and construction as the existing stairways.