Wood Design Values

[DCEngr1]

Wood Engineers,

I need to know the design values for wood, specifically, SYP, for components that are nominally 1x. Design value tables specify 2x as being the smallest dimensional lumber having tabulated and published values, as I have seen anyway. A link to information that could assist me would be appreciated.

Thanks.

 

[Guastavino]

I don't have a link, but intuitively I would think using the values for 2x lumber would be reasonable. Think about Timbers which are bigger sizes, design values are smaller than 2x, etc.

With that said, using 1x lumber for a structural application raises a red flag in my mind.

 

[DCEngr1]

Considering using a 1x on each side of a web of a mfgr'd. roof truss for repair. The load is less than 200 pounds tension.

 

[XR250]

1x4 with 200/2 lbs tension = 38 psi axial stress. I think that is reasonable :>
A 2x is probably up around 800 psi.

 

[Triangled]

I've seen 1.125" net thickness lvl materials around

 

[jayrod12]

Why not just use plywood. Then you have tabulated values you can fall back on. As XR noted, the stress is so low that member strength likely shouldn't be a problem. My question would be in regards to the connection strength for screws and nails. I don't think those would be proportional.

 

[mike20793]

I agree with jayrod. Just spec 3/4" plywood and be done with it.

 

[XR250]

…..or just spec 2x4's so nobody has to spend the time to rip plywood.
2x4's are probably actually cheaper than 1x4's and definitely cheaper than a sheet of 3/4" plywood