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Community and Q&A

Installing Tongue-and-Groove Flooring Over Joists

Michael_Kalman | Posted in General Questions on

Is it acceptable to install 3/4” T+G flooring over joists? The joists would have 5.5” open cavity with nothing inside so they would sound hollow, but there would be 5” of spray foam just under the whole joists system, under the 2×6 joists that is insulating the top of the metal pan under the tiny house trailer.

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  1. Expert Member
    Akos | | #1

    This is pretty common in older houses. Tends to be very squeaky and bouncy. I've done 2x6 T&G without a subfloor, which is much more solid but still squeaky.

    I would stick to standard construction. If you want thin, go for an engineered or laminate floor over proper subfloor.

    1. Michael_Kalman | | #2

      Do you think 1/2” ply under the 3/4” t+g is better than nothing or should I go back to the original 3/4” I had before the water damage

      1. Expert Member
        BILL WICHERS | | #3

        I would go with 3/4” which is standard. I’d also screw it down (or use scrails), and probably glue too. Squeaky floors are annoying, and this is one of those things that you really want to do right the first time. Nails alone tend to lead to squeaky floors later.


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