Waterproof new pipe penetration tru old concrete wall

[ajk1]

Has anyone had any experience with waterproofing below grade new pipe thru an exisitng reinforced concrete wall where cannot access the exterior face of the wall?

The new 2" diameter copper water supply pipe was installed today by "torpedoing the pipe thru the soil so there is no excavation on the outside face of the wall. The hole thru the wall was core drilled from the inside of the building. The pipe and some electrical wires for the remote reading water meter come thru the same hole as the pipe (see attached). I was thinking of filling the hole with a urethane foam, but I do not know if there might be any adverse reaction with the copper pipe or with the electrical wires. Anyone know? Any other ideas?

 

[ishvaaag]

It seems that silicone could well be the first against copper and pvc, maybe some pore sealant to concrete, then again silicone on all...

http://www.rectorseal.com/index.php?site_id=1&product_id=190

Searching for the words, as always, in google.

 

[Ron]

I would not use silicone. It contains a lot of acetic acid, which will attack the copper.

I would coat the copper as well as you can with asphalt mastic or wrap with butyl tape, then foam the annular space as you thought.

Coat the inside face of the foam with urethane, such as Vulkem 350 or similar.

 

[msquared48]

Okum?

Mike McCann
MMC Engineering

 

[ajk1]

My understanding is that if a "neutral" silicone is used it does not contain acetic acid, and that most silicones these days are neutral so there is no prpblem sourcing this material -- that was not the case 20 years ago where I saw a case where the silicone did cause corrosion of steel due to acetic acid in the silicone. But as you note, maybe better to stay away from silicone for this case, to be safe.