# Sealing concrete foundation around water pipe



## stadry (Jun 20, 2009)

dig down 6" BELOW the penetration, clean wall, then coat w/roofing cement,,, apply 6mil pvc sheet membrane press'd into the soft cement, then coat w/another layer of cement,,, be careful w/backfill that no rocks/sticks ruin your work,,, also realize the soft backfill will allow water to flow down.

if you don't do this right, you can always inject hydrophyllic polyurethane grout from the inside :furious:


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## Bondo (Dec 8, 2007)

Ayuh,... Pack it with Grout...


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## Termite (Apr 13, 2008)

Yeah, I think the roofing cement idea would work but I think it is gross overkill.

Hydraulic cement (hydroplug) is a waterstopping cement product you can buy in small dry mix buckets at home centers. Mix it to the consistency of peanut butter and pack it in the annulus around the pipe from both sides. It will make a very tight and watertight seal. This is how it is done in new construction as well as situations like yours. Basic cement mix will probably shrink as it dries and will not be as effective, so make sure you get hydraulic cement.


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## shtoink (May 7, 2008)

Thank you, gentlemen!


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## stadry (Jun 20, 2009)

ohmigawd, the moderator said ' annulus '  'mite, the reason i suggested that method's because we've seen too many hydraulic attempts fail,,, a supporting reason is we'd only want to do the job once,,, callbacks hurt your credibility & we saw too many jobs which didn't go ALL the way to resolve the leaks.

that's not to say there isn't a space for hydraulic cement - it would work outside but only maybe & that's not good enough for us,,, now go wash your mouth out w/soap :laughing:


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## shtoink (May 7, 2008)

I'm not sure I'd want a hydroplug anywhere near my annulus.

I have a little bit of leftover roofing cement and some poly so I might try that method first anyway.

Thanks again!


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## Daniel Holzman (Mar 10, 2009)

I used expanding foam (Great Stuff) with good success when I put a 2 inch pipe for a sump pump through my concrete basement wall. Its been 15 years with no problem. I also used silicone caulk on one penetration, ten years with no problem. I have never used hydraulic cement for sealing a penetration, not saying it wouldn't work, but I am not sure how easy it would be to pack it into a deep space, like a 6 inch thick concrete wall.


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## stadry (Jun 20, 2009)

forgot all about that ' stuff ', dan, but your discharge's only gravity & there's not a whole helluva lot of head pressure there - especially if your discharge's above grade as are most,,, as w/most waterproofers, we're VERY aware of our annulus, too :huh:.


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## Termite (Apr 13, 2008)

Try to give some sage advice and all I get is sarcasm. :no:

Maybe "gap" is more acceptable?


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