Roof Diaphragm for Solar Array

[jt0716]

In order to determine the load a roof can handle, I typically analyze one of the rafters, and convert the uniform roof load to a distributed load on each rafter. Long story short, I check up to deflection criteria. My question is, how do I account for roof sheathing as a diaphragm which in turn reduces deflection to one rafter and transfers load to adjacent rafters. Is there a code reference?

 

[hokie66]

IRstuff,
The load of the sheathing, tile, snow load, etc is shared by each rafter, but the sheathing can't be assumed to assist in redistributing point loads on an individual rafter.

 

[a2mfk]

Not to be pushy, but a sketch of the exact rack or a picture of the installed set up may get you a lot of quality suggestions. Or go tell the contractor the seemingly inevitable bad news...

 

[IRstuff]

Was that sheathing stiffness in the analysis?

TTFN

FAQ731-376

 

[hokie66]

IRstuff,
Stressed skin analysis is just not used in design of residential structures.

 

[IRstuff]

OK, sounds like it's time to get out the crowbars...

Or, can additional supports be inserted on the intervening rafters?





TTFN

FAQ731-376
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