Built up wood beams - is live laod reduction permitted?
Built up wood beams - is live laod reduction permitted?
(OP)
The 2004 Span Book (and perhaps in the edition latest as well, but I do not have that) gives load reduction factors for 2-ply lintels supporting combined roof and floor loads.
Questions:
1. Would I be correct in assuming that this applies only to live loads? It seems strange that it does not say that it applies to live load only, either in Table 1 or in paragraph 7.30
2. Why is this limited to 2-ply lintels? Can the same factors be applied to 3-ply ground floor perimeter beams supporting the exterior bearing stud wall of a cottage?
Questions:
1. Would I be correct in assuming that this applies only to live loads? It seems strange that it does not say that it applies to live load only, either in Table 1 or in paragraph 7.30
2. Why is this limited to 2-ply lintels? Can the same factors be applied to 3-ply ground floor perimeter beams supporting the exterior bearing stud wall of a cottage?






RE: Built up wood beams - is live laod reduction permitted?
1. I would say yes on the reduction for live loads only, snow NOT being considered a live load.
2. I would say yes on the reduction allowance PROVIDED that the multiple member beams and headers are loaded uniformly across the top, i.e., equally to all the members of the beam/header. Should the member receive loading from the side, such as hung joists or beams, I would say no.
Mike McCann, PE, SE (WA)
RE: Built up wood beams - is live laod reduction permitted?