O-1954-476 - Laserfiche WebLink

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..... -.... . , " " 'l!!!! , --. . - 19 - 6. ENCLOSURES OF INTERIOR STAIRWAYS. (a) All interior stairways in buildings eonnecting two or more stories" whether required as exits or not" shall be enclosed, except as otherwise provided in paragraph (d). (b) In unsprinklered buildings which exceed 30nfeet to the floor of the topmost story" or are occupied by more than 75 persons above.. or 40 persons below" the first story above grade, not counting those in the first story, and in multifamily houses 4 stOries or more in height" interior required stairways shall be enclosed with fire partitions. (0) In other buildings interior sta:bhvqs shall be enclosed in par- titions having a fire resistance rating of not less than one hour. In buildings of fireproof construction and semifireproof construction such partitions shall be noncombustible. (d) An enclosure shall not be required for: (1) A flight of stairs from the main entrance floor to the floor next above when such stairs are not a part of a required stairway. (2) A flight of stairs in a building of fireproof con- struction" semifireproof construction" or a sprinklered building of heavy timber construction or ordinary construction or nonoombus tible construction.. when suoh stairs connect only one story with one c:t her story immediately above or below it. In such case the upper end of. the .stairway shall not connect to a hallw~ ~ am an exit except through a fire door. (" A flight of stairs from a balcony or mezzanine having an area not exceeding 25 per cent of that of the floor inDnediately belav. (e) OPENINGS. No openings except the necessary doorways" and windows opening to the exterior of t he building" shall be permi. tted in a stair enclosure re:Quir:ed by this section. Such doorw~s shall be equipped with approved self-closing doors.. except that when fire partitions are not required for the enclosure" substantial self~closing metal or metal covered doors or solid wooden doors of the flush tYl2 of nominal thickness not less than I 3/4 inches may be used. In school buildings.. doors on openings in stair enclosures may have wired glass panels) the area of such glass in anyone door shall not exceed 720 square inches. 1. WIDTH OF mTmIm STAIRWAYS. The minimum \mobstructed width of a stairway serving as a required exit shall not be less than 44 inches; provided that in multifamily houses and storage buildings" and in other buildings occupied by a single tenant and limited in occupancy to 40 persons" such vd.dth may be 36 inches. The width of stairs shall be measured between hand rails ex cept where hand rails project not more than 3i inches into such width.