Helpful? 1

Rigid foam sandwiched in wood subfloor?


I'm re-doing my living room floor.

When I strip it down to the T&G subfloor, I will have about 1" to make up, since it will be lower than the kitchen floor it butts up against.

Below is an unfinished. basement.

Originally I was going to do OSB as a base with a layer of thinner plywood to get up to the proper height. But I have seen a lot of people doing rigid foam in their basement floors - Foam, then ply or OSB, with flooring on top.

Can I do this here, to get a little extra insulation between my living room and the basement? I was thinking 3/8 or 1/2 rigid foam, followed by 5/8 or 1/2 plywood.

Is this acceptable? Is there a reason foam would be OK over a slab, but not over a T&G subfloor?

Thanks for any help! And let me know if you need to know more

Asked by Sean Cunningham
Posted Fri, 03/07/2014 - 12:42
Edited Fri, 03/07/2014 - 13:26


1 Answer

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Helpful? 0

Yes, you can do that.

It's even possible to leave the 1-inch height difference between rooms, and to simply make a custom tapered threshold at the doorway. Of course, some homeowners hate that idea; others don't mind. Such tapered thresholds are common in older homes, where flooring is replaced in one room at a time, on different schedules.

Answered by Martin Holladay, GBA Advisor
Posted Fri, 03/07/2014 - 13:09

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