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Sealing Poly to Footing Wall

Cody Fischer| Posted inGeneral Questionson

I’m looking for product / technique guidance on how to best seal 10 mil poly to a concrete footing wall.

I have a slab on grade sitting on top of 5″ of EPS with 10 mil poly sandwiched between. There is also a 2″ thick vertical piece of EPS separating the edge of the concrete slab from the footing wall at the perimeter of the slab. The footing walls around the perimeter of the slab continue past the slab and make up ~12″ of the ground floor wall.

The poly under the slab is wraps up the interior side of the footing wall. In order to prevent radon leakage, I’m assuming we need to do a good job of sealing the poly to the footing wall, but we aren’t sure how best to do it.

Acoustical sealant?

Primer + one of the following tapes: Polyken Shadowlastic, Siga Wigluv, Siga Sicrall, Pro Clima Tescon No. 1, Venture 1585 HT/W, or Dow Weathermate.

I’m not sure Wigluv works on concrete (its not listed as one of the workable substrates).

Thanks for any guidance!

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Replies

  1. Expert Member
    Michael Maines||#1

    The stickiest tape I know of for this type of condition is Siga Fentrim. In most cases, no primer is needed.

  2. Cody Fischer||#2

    Thanks Michael - and you agree that the poly does need to be sealed to the concrete wall here? And you believe a tape would work better than acoustical caulk?

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