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DATE/TIME TYPE OCCUPANCY CONST TYPE UGB: SITE: BUILDING PERMIT 04/21/99 16:22 Commercial addition/alteration S-5 II-N 13. 14, 15. 16. 17. 18, PERMIT NO 99-01946 STATUS ISSUED ISSUED 04/21/1999 TO EXPIRE 10/18/1999 PAGE 3 Stairways in Type II-N buildings shall be of noncombustible construction. Stairways shall comply with the requirements of Chapter STAIRWAY WIDTH, (OSSC Sec 1003,3.3) The minimum stairway width serving an occupant load of 49 or less shall not be less than 36 inches, Handrails may project into the required width a distance of 2-1/2 inches from each side of a stairway. Stringers and other projections such as trim and similar decorative features may project into the required width 1-1/2 inches from each side. STAIRWAY RISE & RUN. (OSSC Sec 1003.2.3) The rise of steps and stairs shall not be less than 4 inches nor more than 7 inches. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 2/8-inch. Except as permitted in Sections 1002.3.2.8~1. 1003.3,3.8,2 and 1003.2.3,8.3, the run shall not be less than 11 inches as measured horizontally between the vertical planes of the furthermost projection of adjacent treads or nosings, Stair treads shall be of uniform size and shape, except the largest tread run within any flight of stairs shall not exceed the smallest by more than 3/8-inch. STAIRWAY RISE & RUN, cont'd. EXCEPTIONS: 1, Private steps and stairways serving an occupant load of less than 10 and stairways to unoccupied roofs may be constructed with an 8-inch-maximum rise and a 9-inch- minimum run. 2. Where the bottom or top riser adjoins a sloping public walk or driveway having an established grade (other than natural earth) and serving as a landing, the bottom or top riser may be reduced along the slope to less than 4 inches in height with the variation in height oF the bottom or top riser not to exceed 1 in 12 (8.3% slope). HANDRAILS. (OSSC Sec 1003,2.3.6) The top of handrails and handrail extensions shall not be placed less than 34 inches nor more than 38 inches above landings and the nosing of treads. Handrails shall be continuous the full length of the stairs and at least one handrail shall extend in the direction of the stair run not less than 12 inches beyond the top riser nor less than 12 inches beyond the bottom riser. Ends shall be returned or shall have rounded terminations or bends, EXCEPTIONS: 1. Private stairways do not required handrail extensions, HANDRAILS. cont'd. EXCEPTIONS, cont'd: 2. Handrails may have starting or volute newels within the first tread on stairways in Group R, Division 30ccupan cies and within individual dwelling units of Group R, Division 1 Occupancies. The handgrip portion of handrails shall not be less than i-l/4 inches nor more than 2 inches in cross-sectional dimension or the shape shall provide an equivalent gripping surface, The handgrip portion shall have a smooth surface with no sharp corners. Handrails projecting from a wall shall have a space not less than I-i/2 inches, INTERIOR STAIRWAY CONSTRUCTION. (OSSC Sec 1002.3.3,9) Interior stairways shall be constructed based on type of construction requirements as specified in Section 603.4. Except where enclosed usable space under stairs is prohibited by Section 1005.3.3.6, the walls and soffits of such enclosed space shall be protected on the enclosed side as required for one-hour fire-resistive construction. Stairways exiting directly to the exterior of a building four or more stories in height shall be provided with a means for emergency entry for fire department access, GUARDRAILS. (OSSC Sec 509) Unenclosed floor and roof openings, open and glazed sides of stairways, aisles, landings and ramps, balconies or porches, which are more than 30 inches above grade or floor below,