NFPA 220-1999 Standard on Types of Building Construction

NFPA 220-1999 Standard on Types of Building Construction. 3-4.2 Wood columns supporting floor loads shall be not less than 8 in. (203 mm) in any dimension; wood columns support- ing roof loads only shall be not less than 6 in. (152 mm) in the smallest dimension and not less than 8 in. (203 mm) in depth. 3-4.3 Wood beams and girders supporting floor loads shall be not less than 6 in. (152 mm) in width and not less than 10 in. (254 mm) in depth; wood beams and girders and other roof framing supporting roof loads only shall be not less than 4 in. (102 mm) in width and not less than 6 in. (152 mm) in depth. 3-4.4 Framed or glued laminated arches that spring from grade or the floor line and timber trusses that support floor loads shall be not less than 8 in. (203 mm) in width or depth. Framed or glued laminated arches for roof construction that spring from grade or the floor line and do not support floor loads shall have members not less than 6 in. (152 mm) in width and not less than 8 in. (203 mm) in depth for the lower half of the member height and not less than 6 in. (152 mm) in depth for the upper half of the member height. Framed or glued laminated arches for roof construction that spring from the top of walls or wall abutments and timber trusses that do not support floor loads shall have members not less than 4 in. (102 mm) in width and not less than 6 in. (152 mm) in depth. Exception: Spaced members shall be permitted to be composed of two or more pieces not less than 3 in. (76 mm) in thickness where blocked sol- idly throughout their intervening spaces or where such spaces are tight- ly closed by a continuous wood cover plate not less than 2 in. (51 mm) in thickness, secured to the underside of the members. Splice plates shall be not less than 3 in. (76 mm) in thickness. 3-4.5 Floors shall be constructed of spline or tongue-and- groove plank not less than 3 in. (76 mm) in thickness that is covered with 1-in. (25-mm) tongue-and-groove flooring, laid crosswise or diagonally to the plank, or with 1 / 2 -in. (12.7-mm) plywood; or they shall be constructed of laminated planks not less than 4...