O-1952-429 - Laserfiche WebLink

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6. (a). Wooden columns in the several stories of a building, shall be set directly above one another, on top of the column below. (b). The loads on wooden columns shall be transmitted to the columns below through reinforced concrete or metal caps with brackets, or through metal caps and bases with pintle connections or other approved column connections; provided that wooden bol- sters may be used to support roof girders. 18 5. Load-bearing partitions. (a). Load-bearing partitions shall be the equivalent of 2 x 4- inch studs, nominal dimensions, spaced not to exceed 16 inches on centers with the larger dimension perpendicular to the wall. All openings shall have studs doubled on each side and if more than 3 feet and 6 inches wide they. shall be trussed over or shall have lintels of sufficient size to carry the load. (b). Load-bearing stud partitions shall have top plates not smaller than double 2 x :4-inch, nominal dimensions, and shall be set over girders or other partitions below, with the space between the ceiling and the floor above firestopped with solid 2-inch, nominal thickness plank, or with noncombustible material. Wooden columns. .' . 2. Walls. Exterior enclosure and stable weatherproof exterior. 19 l;~ walls SECTION NONCOMBUSTIBLE CONSTRUCTION 1. Definition~ Noncombustible construction, as applied to buildings, means that in which all structural members, including floors, roofs and their supports, are of steel, iron, concrete, or of other noncombustible materials, and in which the exterior walls are of noncombustible construction having a fire resistance rating of not less than t,vc hours. shall provide a durable 18. 9. Mansard roofs. Mansard or other slanting roofs having a pitch of more than 600 from the horizontal, hereafter placed on a building over 40 feet in height, shall be of fireproof construction or semifireproof construction. 10. Draft stops in attic spaces. Attic spaces shall be divided into areas of 3.000 square feet or less by tight draft stops; these shaIl be of 2 thicknesses of I-inch lumber with joints broken or the equiva~ lent, with access doors of similar construction. 4. (a). All trimmers and at least one beam or joist in every six feet resting on masonry walls, shall be secured to such walls by approved metal anchors attached at or near the bottom in a manner to be self-releasing. Each end of a trimmer, beam or joist that is supported by a girder, shall be secured or tied in an approved manner to such girder or to a trimmer, beam or joist correspond- ingly supported from the opposite side of such girder. Anchors and ties shall be so arranged as to form continuous ties between opposite masonry walls. (b). Where floor or roof joists or beams run parallel to ma- sonry walls such walls. shall be secured to 4 or more joists of the floor or roof construction by approved metal anchors at maximum intervals of 8 feet for dwellings, and 6 feet in other buildings. (c). Wall plates and roof construction shall be anchored to the walls at least every 6 feet. (d). Wooden girders shall be anchorec;l to the walls and fas- tened to each other with suitable steel straps placed near the bottom of the girder. . :t ~ . (d). Joists shall be dO~d under partitions which run over and parallel to the joists, or shall be designed for the load.. (e). The ends of wooden beams and joists resting on masonry shall be cut to a bevel of 3 inches in their depth. (f). Wooden joists, beams and girders resting on opposite sides of a masonry wall shall be separated from one another by at least 6 inches of solid masonry. (g). When a wooden girder rests on masonry an air space of o inch shall be provided on the sides and end of such girder for ventilation, and each wall bearing end of a girder shall be cut on a bevel. Anchorage. . . 7. Firestopping. (a). When the walls are furred, the space created by the fur- ring shall be firestopped with noncombustible material at floors, ceilings and roofs. The firestopping shall be the full thickness of the furring and extend from the ceiling to the underside of the flooring or roof. (b). When joists run parallel to the wall the space between the wall and nearest joist shall be not less than 1 inch and shall be solidly filled with masonry or approved noncombustible material. (c). Interior stud partitions shall be firestopped at the floors and ceiling of each story by a 2-inch nominal dimension, wood plate, the width of the stud, or the equivalent. (d). When sliding doors are pocketed in partitions, such pockets shall be completely firestopped at the top, bottom and ends, with noncombustible material or with wood not less than 2 inches in thickness nominal dimension. (e). Joists shall b.e firestopped at the ends and over supports for the full depth of the joists with noncombustible material or with wood not less than 2 inches in thickness, nominal dimension. (f). No firestopping shall be covered or concealed .until in- spected by the building official. 8. Bay windows and show windows. Bay windows and show windows that extend beyond exterior walls shall be constructed of noncombustible materials; except that show windows that do not extend above the second story floor level and bay windows on dwellings may be constructed of wood; when such bay windows of wood are more than 10 feet in width they shall be covered on the exterior surfaces with metal or other approved noncombustible, weatherproof materials. e e (c). Wooden columns shall no~st directly on floor joists. (d). When supported by masonry, suitable stone or metal bases shall be set between the column and the masonry.