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  • Seal cracks in concrete slab?

    Posted by Matt on April 8, 2021 at 10:11 am

    Our house was built in 1975 and has, of course, settled a little bit. There are several cracks in the slab. They are very thin and there’s no big displacement. Should I seal the cracks before laying the floor. My planks call for a 6mil poly sheet and I am also using the optional underlayment pad made by the same manufacturer (Corelux). Any recommendations as to which sealant (e.g. Bluestar, Quikcrete, Crackweld)? Thanx!

    Keith replied 1 year, 11 months ago 3 Members · 2 Replies
  • 2 Replies
  • Joe

    April 8, 2021 at 3:10 pm

    Yes, if they are open an 1\8 inch or more and you can use henry’s 549 feather finish. Anything less you will be good to go.

  • Keith

    June 26, 2021 at 3:35 pm

    Hi Matt… Sorry if this is way too late but perhaps for the benefit of others… Independent of any floor installation concerns, I would seal it just to reduce radon gas. I use to live in an area of the country where it as heavy and years ago we replaced carpet on a slab and did radon readings before and after but we sealed all cracks, even hairline ones and actually sealed the surface as well. It made a significant difference in the gas level afterward. Of course, if radon readings are very high there is venting equipment people can get installed.