Specifying lumber sheathing boards?
Specifying lumber sheathing boards?
(OP)
I have a project where the Architect wants to use 1x12 lumber sheathing boards as the roof decking over rafters spaced at 24 inches on ceneter. However, I am having trouble finding information on how to spec this and check its strength for all loading conditions. The sawn lumber section of NDS only appears to apply to members 2" nominal or greater.
Any help would be greatly appreciated.
Any help would be greatly appreciated.






RE: Specifying lumber sheathing boards?
RE: Specifying lumber sheathing boards?
The Timber Construction Manual 4th ed on pages 6-400 to 6-402 includes a table (Figure 6.11) that shows spans c-c in. to total uniform load (for 1x, deflection = l/240, MoE = 1800000psi, Fb = 1200psi) that shows 34" c-c will support 60psf. So 24"oc rafters is 34'oc at 45 degrees.
How the Timber Construction Manual values would compare with the 2009/2012 IBC lumber I could not say.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Specifying lumber sheathing boards?
SDPWS doesn't give grading requirements.
RE: Specifying lumber sheathing boards?
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Specifying lumber sheathing boards?
I find it hard to believe you would have trouble with 1x boards spanning 24" o.c. in a roof application which may require a beam/span analysis. The diaphragm action is where you need to be attentive I would think.
______________
MAP
RE: Specifying lumber sheathing boards?
What type of board is the SDPWS referring to? They gave nailing options of 1x6 and 1x8 members, but do not mention a material grade requirement. I figured I could try to use 1x12 members with a equivalent nailing frequency and get the same diaphragm values.