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How to seal water line on outside to prevent leak into basement

23K views 14 replies 8 participants last post by  alexjoe 
#1 ·
This post is similar to a question I posted a few months ago. However I have some new questions with which I would appreciate help.
See attached drawing for reference.

My 1 inch plastic water pipe from the utility comes through the basement wall inside an 8 foot PVC sleeve which runs underneath the front porch. The sleeve runs **downhill** (unfortunately!!) from the front of the porch to where it enters the basement wall. In the basement, there is GE Silicone II caulk in the space between the inside of the sleeve & the outside of the plastic water pipe to prevent any water in the plastic sleeve from leaking into the basement.

NOTE: The caulk seal originally lasted for 10 years without any leakage of water into the basement.

Recently I had plumbing work done in the basement & I had to re-caulk the space between sleeve & plastic water pipe with GE Silicone II caulk. This caulking job only lasted 3 months when it started to leak drops of water. I was able to confirm that the caulk was no longer properly adhering to the plastic water pipe & water was leaking where the caulk met the plastic water pipe. Thus the silicone caulk was no longer adhering to the plastic water pipe.

NOTE: There is very little space between PVC sleeve & plastic water pipe, probably not enough space into which to inject expandable foam? Also note that the plastic water pipe is **not** centered in the middle of the PVC sleeve when it enters the basement. There is a 1/32 inch clearance between the bottom of the plastic water pipe & PVC sleeve.

I want to fix this problem by one of two methods:
(1) Inside the basement: Re-caulk the space between PVC sleeve & plastic water pipe.

(2) Outside the basement, seal the space between PVC sleeve & plastic water pipe. This would require digging approx. 3 feet down to the water piping.

I realize that method #2 is a more permanent solution. But method #1 worked for 10 years before I had to re-caulk, so I would first like to try method #1.

QUESTIONS :
(1) For method #1: Is there a better material besides GE Silicone II 100% caulk that can be used to seal between the sleeve & plastic water pipe? Would "Plumbers GOOP" be better? A plumber mentioned that there is some type of rubberized cement that has the consistency of putty that can be used (he will be getting back to me on the actual name of this material) - any thought on this?

(2) For method #2: How can I permanently seal the space between PVC sleeve & plastic water pipe outside the house? If I caulk this space, won't I have the same problem that I am having in the basement?

Thank you for your help!!!!
 

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#2 ·
How to seal water line on outside...
You need to dig.
That might mean a shovel...
it might mean a back hoe and trench shoring.

You may find that the problem is limited to one spot..
You may find that the whole length warrants replacing.

The contractors around you (who do this every day) can probably look at it, then "guess", and be right 8 out of 9 times.
 
#6 ·
Dig on the outside and then fix it from there. Sure the thing functioned perfectly fine without a leak for 10 years before the caulk on the inside got disturbed, but this doesn't mean re-doing the inside caulk will get everything back to A-OK. What I am betting is whatever work that was done on the inside moved the pipe around enough to disturb the seal where it enters the wall. If water is entering from outside the wall, caulking the pipe on the inside won't keep the water out. It will let it in part way and then trap it and build up pressure until the seal breaks and it comes in again. This is why your first attempt didn't work. Water entering from outside the wall build up pressure and eventually forced its way through the new caulk.

I have had water intrusion around a pipe before. 3 different contractors told me the same thing: No inside repair would be permanent. The only way they would want to attack it would be to dig, then clean the area around the leak, then use mortar or hydraulic cement to patch the wall. Then they would go over that with an asphalt type substance and finish it off with a plastic water-proofing membrane. They would also re-caulk or put hydraulic cement around the pipe on the inside to re-seal it, but that was mainly for aesthetic purposes and to prevent spiders or other insects from coming in around the pipe. Even without doing anything on the inside, the leak would stop permanently because of the outside patch.

Depending on how severe yours is you may not necessarily need to use so many redundant layers to patch the wall. But at minimum you will want to get some sealant, caulk, hydraulic cement, or mortar in there from the outside wherever the water is getting in. Then consider laying a plastic membrane over that and calling it a day. It is hard to know the best way to attack it until you dig down and see exactly how the pipe goes in and what the problem is, but at least two layers of protection will probably be needed.
 
#9 ·
I don't think your caulking fix failed because of a great build-up of water pressure. Your caulking job likely failed because your new silicone caulk did not stick very well. A problem with silicone is that nothing sticks to it very well, and you likely left a film of old silicone on the components.
Visit this thread and scroll down to Nestor's method for re-applying silicone caulk :http://www.diychatroom.com/f80/recaulking-previously-silicone-caulked-shower-door-frame-15069/
Not saying you need to follow the shower procedure for your situation --- just saying its not as simple as slapping more silicone over top. In your case, if you can manage to clean everything with fine emerycloth you might get a good bond. For myself, my first choice for high performance caulking is polyurethane.
 
#11 ·
I agree that if the pipe was sealed on the other side, there would be no problem and I would not have had to post for help. But also important to remember that there were no leaks for 10 years!! Silicone caulk held back the water for 10 years. Only when I had to re-caulk the space between PVC sleeve and plastic water pipe did I have a problem. So if it worked for 10 years in the past, it should work now?
 
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