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Sealing a below-grade foundation wall penetration

What are the current acceptable approaches to sealing pipe penetrations through a below-grade foundation wall?

I've heard
1. high viscosity polyurethane
2. Low-expansion urethane foam + boot outside (fine homebuilding)
3. Other various boots

I will have a dimple membrane on the exterior.


Asked by rossn1
Posted Jul 13, 2018 12:55 AM ET


6 Answers

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The dimple mat (if it is properly installed and integrated with a good footing drain) will take care of the hydrostatic pressure. If you use a high-quality caulk or European tape, you should be fine.

Answered by Martin Holladay
Posted Jul 13, 2018 5:10 AM ET


Also slanting the pipe so water is channeled outward.

Generically, I'd favor seals that still seal with high movement - compressed foam gaskets, rubber, maybe bentonite in some special cases.

Answered by Jon R
Posted Jul 13, 2018 10:59 AM ET


Pouring a sleeve into the foundation for all penetrations is the way to go. schedule 40 PVC or ABS sized to accommodate the pipe and some sealant or a gasket. That way you aren't trying to seal the pipe to concrete.

Answered by Malcolm Taylor
Posted Jul 13, 2018 11:14 AM ET


Thanks, guys -- all good ideas and information. Sika recommended one two-part product, and Titebond recommended their weathermaster ultimate MP, which I'm finding to be a very versatile adhesive+sealant that isn't to toxic and they report bonds well to almost everything. Since I already have some, I think I'll use that. Good ideas on the slope, sleeve, and tapes.

Answered by rossn1
Posted Jul 13, 2018 9:00 PM ET


The best products I've seen so far . Have not had one issue with these .


Answered by Richard McGrath
Posted Jul 16, 2018 8:30 AM ET


If GBA readers don't want to be held in suspense as they watch a video, the product that Richard is talking about is called Link-Seal. It is manufactured by GPT Industries.

Here is a link to the relevant web page for this product: Link Seal modular seals.

Answered by Martin Holladay
Posted Jul 16, 2018 8:41 AM ET

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