In all buildings erected after February 20 1917, except private dwellings, which are used above the first floor for business purposes or public assemblages, or for any purpose whatever if over three stories high, the stair shafts shall be separately and continuously enclosed by incombustible partitions, unless such buildings are provided with outside fire escapes. Elevator shafts in all buildings erected after said date shall be enclosed in the same manner. The partitions shall be constructed of brick or other fire-resistive material, approved by the inspector or other designated official, and all mortar used in the construction shall be cement mortar. No such hollow partition shall be less than six inches thick. No brick partition shall be less than eight inches thick and no other solid partition less than four inches thick. Except as herein stated, the stair, elevator or hoistway shafts in all buildings over two stories high in existence on February 20 1917 of the class described in this section shall be separately enclosed by incombustible partitions as above specified or the shafts may be enclosed (a) by approved hollow or solid partition blocks not less than three inches thick, set in portland cement mortar, (b) by four-inch stud partitions covered on each side with not less than three-quarter inch of portland cement plaster on metal lath or (c) by two-inch solid metal lath and portland cement plaster partitions. The metal framework of such partitions shall be securely fastened to both floor and ceiling. All lath used for such partitions shall be of galvanized steel, weighing not less than fifty-four ounces per square yard. Wire lath shall not be less than No. 20 gauge and sheet metal lath not less than No. 24 gauge. All such partitions erected in buildings in existence on February 20 1917 shall be firestopped with incombustible material the full depth of the floor beams at each floor level. The enclosure walls for all elevator shafts shall extend at least three feet above the roof and at least three fourths of the area shall be covered with a skylight constructed as specified in Section 5-25-850.

HISTORY: 1962 Code Section 47-1250; 1952 Code Section 47-1250; 1942 Code Section 7516; 1932 Code Section 7516; Civ. C. '22 Section 4631; 1917 (30) 77.