GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X 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

What product to use when filling the gap left after the slab has shrunk?

user-985898 | Posted in General Questions on

I went to the big box store and purchased Sika polyurethane foam for concrete and masonry. Will this work or should I use another product? I plan on using a Sika concrete caulk sealant made for sealing cracks in foundations for the narrow areas. Oh by the way, I want to thank GBA for all of the advice I got when building our house in PA.

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.


  1. GBA Editor
    Martin Holladay | | #1

    It sounds like you have the right products. The sealant or caulk is good for the narrower cracks, and either grout or polyurethane foam is appropriate for the wider cracks.

  2. user-2310254 | | #2

    I think you should use the polyurethane sealant, which is intended for filling cracks and control joints. It's likely to do a better job than the foam, which Sika's literature indicates will not adhere to any release agents that might be present in the concrete. It also will be easier to work the sealant and create a smooth joint.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |