GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

How long do I need to wait before installing flooring over fresh concrete?

Tim Mullen | Posted in General Questions on

We are removing and replacing an existing basement slab for a residential project in Silver Spring Maryland. It is a split level, half the basement is slab, the other half is on a dirt crawl space. We are planning either a bamboo, glue down hardwood floor (prefinished), or a Bruce engineered prefinished floor. Is there any benifit in terms of waiting time, if we use a high early cure concrete mix? Bruce is saying 30 days per inch of slab. I don’t want to compromise the finish product, so I will wait if need be.

Any advice, or opinion?

Thanks,
Tim

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. GBA Editor
    Martin Holladay | | #1

    Tim,
    First of all, I hope that you are including continuous rigid foam insulation under your new slab, with a layer of poly between the foam and the concrete.

    It's very important to allow the concrete to cure fully before installing finish flooring. Either follow the waiting period suggested by the flooring manufacturer, or else perform a calcium chloride test to verify that the slab’s moisture level has dropped to within the specifications of the flooring manufacturer.

  2. Mike Collignon | | #2

    Concrete is never truly done curing, but the minimum wait time should be 28 days. A slab typically cures at least 80% during that time.

    I suspect the manufacturer is asking you to proceed cautiously to avoid a lawsuit. If you (or your client) can wait that long, then wait the 120 (or more) days. But I wouldn't put any flooring on it inside a month.

    To double check with a legit concrete expert, I would suggest calling Terry Collins at PCA. Their main number is (847) 966-6200, and they can transfer you to him.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |