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Hardwood floors on above slab insulated basement floor?

JP_in_NY | Posted in General Questions on


I have read a lot of documentation from this awesome website and used some of the info to insulate my basement gluing directly over the concrete a first layer of 0.75″ of XPS followed by another layer of 0.5″ of XPS in the other direction. I then tapcon’ed a layer of OSB 23/32″ above it. I do not know what’s under my slab besides a dimple mat that goes to a sump pump.
I’ve been in that house in Upstate NY for almost 3 years now and the sump pump container has always been dry. Likewise for the walls, everything dry.

I have added 2″ of XPS on the walls and then framed 2×4 with R15 Rockwool but my question is not for the walls 🙂

It is now time to add floors and would love hardwood ones, but everywhere I go they tell me, no hardwood for below grade.
I haven’t checked the relative humidity in my basement but would a high humidity be the only reason why folks don’t install hardwood floors in basements (they only buy engineered hardwood)?
Based on my explanation, can anyone see an issue putting hardwood floors?


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  1. Expert Member
    Akos | | #1

    Generally the problem with bellow grade wood floors is when installed directly over a concrete slab.

    In your case, installed in a dry basement over foam+plywood, I doubt you'll have any issues. You should still keep an eye the RH in the basement, hardwood plus high humidity is asking for trouble.

    Basement are the one spot in the house where you are guaranteed the inevitable water leak/flood from upper floors. Because of this, vinyl click might be a better option.

  2. user-7687827 | | #2

    Great answer Akos. Would you recommend any particular type of glue for hardwood floors in this situation?

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