Crushing of WSP 2

[Flotsam7018]

Continuation of this old thread: https://www.eng-tips.com/threads/crushing-of-plywood-really.371840/page-2#posts

I've been running into this issue a lot lately and having to block out the subfloor at columns. APA D510 provides a perpendicular to grain capacity of 360 psi for a 0.04" deformation. Any additional thoughts on this matter 10 years later?

 

[ChorasDen]

What precisely is the question that you are asking here? Fcperp is a unique attribute of wood that has values assigned based on a proportional limit approach. This differs from the approach used for other properties (fcparallel, Fb, Fv, etc). Be aware that OSB does not typically have uniform properties through the cross section. Binding and performance of the center fibers may not be identical to the face fibers, due to the method of pressing the product.

SDPWS et. al. make it very clear not to overdrive the nails when framing engineered shear walls and diaphragms using wood structural panels. I would consider fcperp within this same concept, in that we don't want to affect panel properties by causing excessive local damage by exceeding Fcperp, but then again, that's just one engineers opinion.... I also understand the frustration of the low value of 360psi, but such is the nature of a commodity product, and the way APA defines design values for this product line.

 

[Flotsam7018]

I was looking for some updated takes or insight on considering crushing of the sheathing as a failure mode at concentrated loads. Are folks out there looking at this and if so where’s the cutoff for you?

I generally only check crushing of the plates, but when I start using engineered lumber columns, especially over two stories, I will check this and often have to block out the sheathing for the column to pass through. I called Huber a few years back on this as I thought there’s no way Advantech only has 360 psi crushing strength, but was told they don’t have any test data to prove otherwise.