W shape loading? 1

[TonyES]

I have a large W shape as my beam with 6X14 timbers (rafters) every 2' on both sides of the beam, each timber has a 6k reaction. The owners want to place these rafters on the bottom flange of the beam. I've never done that, all I've ever seen is the rafters or joists bearing on top of the beam (top of the top flange). Are W shapes designed such that one can load it an any shape or form or do I need to do some other kind of check. the loading will be equal on both sides so the torsion will be small. Any advice would be great. Thanks

 

[xxpegasus11]

You asked whether you can load W shape on bottom flange - the answer is yes. For your joists, they may either bear directly on bottom flange or you may pack and bolt timber in web and hang joists with joist hangers for instance. In the latter case the joists may even then be lower than the bottom flange. This is a fairly common detail, for instance where beam is to be "hidden" within floor zone. Obviously, other checks may need to be made ( LTB if now different as already commented upon, adequate bearing, continuity if applicable....) but I think you were asking whether loading bottom instead of top flange is something thats done.

 

[TonyES]

Thanks to everyone for the references, advice and debate. I've found what I needed and better understand it all now.thanks