I ripped out the carpets and foam underlayment from the living room of my 1975 oceanside New England townhouse. I’m trying to figure out if this is homasote/ hardboard/fiber board or plywood. I don’t think it’s the latter, because I can basically scratch the surface with my hand, and pieces of paper-like substance come off easily.

Based on some posts I read, this could be fiber board used as underlayment, and there might be plywood underneath. Just wanted to get people’s feedback before I rip out a plank to see.

Floor image Floor image 2

  • 1
    I would get it checked for asbestos before removing it. Sep 26, 2022 at 18:24
  • 3
    Good photos, and very unlikely to be asbestos. Cellulose fibers, glued and compressed.
    – Ecnerwal
    Sep 26, 2022 at 18:46

1 Answer 1


Looks like Homasote® - fibrous with that waffle-weave surface, structure more or less like 1/2" thick paper. Natively gray/grey but aged and carpet underlayment stained, at a guess.

Suitable (I guess) for under carpet. Not suitable for much else on top, I think. We mostly used it for cheap bulletin boards or "better than nothing" insulating layer. Under carpet you'd get some sound isolation as well as the whopping R 0.5 thermal, or whatever it actually is. Functionally (sort of) equivalent to a (non-show) cork layer, but cheap.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.