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11/32" T1-11 siding

11/32" T1-11 siding

11/32" T1-11 siding

I am using 11/32" thick T1-11 plywood panel from Homedepot (4'x8'x11/32") on exterior walls of one story house. The plywood is nailed to the wood studs of the exterior wall directly. The inspector feels that the plywood is skinny. APA has shear values for 5/16" plywood and my shear loads are below that. I have not seen anybody installing g OSB under the T1-11.
Any idea will be appreciated.

RE: 11/32" T1-11 siding

Ask the inspector to prove to you it doesn't work.

It is skinny but the that doesn't mean it isn't capable. I typically use 7/16" OSB on the walls. Plenty of capacity, readily available, and cheap like borscht.

RE: 11/32" T1-11 siding

What is it rated for?
All the T1-11 we use is 5/8".

RE: 11/32" T1-11 siding

So, what are the calculated shear loads with this specific situation and wind and snow loads with this specific 11/32 plywood? Don't let him guess by reading a manual or code blindly using worst-case tolerances and assumed nailing positions!

Do the calc for this specific situation and prove to him (and your future customer) that the plywood is acceptable.

If needed, add more nails. (Too late now to use glue behind the wood, right?) Add shear and reinforced screwed plates at the corners so you don'y have to remove and replace plywood if the current pieces are actually too small. Add inside plywood shear plates.

First, find out if you actually have a problem - then solve it if you do..

RE: 11/32" T1-11 siding

Assert your own authority. From a framing standpoint I have never run into a City Inspector who tries to overrule the engineer. Show him it works

RE: 11/32" T1-11 siding

You have to remember that it is not that thick as the lap joint and the grooves are thinner, maybe 1/2 the nominal thickness. You can use drywall on the inside wall to help with shear using a combined SWS. Or metal brace strapping.
He might be right!

Inspector Jeff

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