Leaky water main sleeve

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by tripletdad, Mar 4, 2011.

  1. tripletdad

    tripletdad New Member

    A copper water main line enters my basement below grade. At the point where the line enters the concrete block, it is surrounded by a 3" PVC pipe. The space between the copper line and the PVC pipe is "sealed" with what appears to be some sort of hardened white foam. There are some visible cracks in the foam.

    Water is trickling into my basement from the PVC sleeve. Not all the time. Only when there is a sudden thaw from 50 degree weather in the middle of winter (I live in Pennsylvania) or when there is a torrential downpour of rain. That is to say, it doesn't happen when there is a normal rain or drizzle, nor does it happen when there is a slow thaw, i.e., 35-40 degrees.

    Indeed, about a month ago, we had unseasonably warm weather (50 degrees) and a rapid thaw, and water trickled in for about 2 -3 hours. Then the temperatures went back down, and the leak stopped. For the last 2 weeks, the temperature has gone up to 40 during the day and back down to 30 at night (a gradual thaw), and it has been bone dry. But then we had a torrential downpour of rain a week ago, and about 2-3 gallons trickled in.

    The water authority "sounded" the line and confirmed that the cooper supply line is not leaking.

    During the winter months, ice damming and freezing of the downspouts occurs directly above the side of the house where the water main enters the basement.

    Plumber #1 said it is necessary to excavate the ground outside, and to re-seal the supply line from the outside, and fix any drainage issues. He gave me an estimate of $4,000.

    Plumber #2 said it is not necessary to dig from the outside. He said that he could re-seal the sleeve from the inside. He also said that the source of the water was the ice damming in the gutter above, and that if the ice dams were eliminated, and the sleeve were re-sealed from the inside, the problem would be fixed. Plumber #2 gave an estimate of $800 to re-seal the sleeve from the inside.

    Whom do I believe if I want to fix the problem correctly and permanently???

    Plumber #2 is at least partially wrong, since the gutters are now clear of all ice and snow, and conducted the recent rainwater perfectly -- without any overflow. That leads me to believe that something more is necessary, than simply re-sealing the sleeve from the inside.

    On the other hand, I certainly don't want to dig up my entire front yard, and pay $4,000, unless it's absolutely necessary.

    Two additional facts that may be helpful. First, the water authority technician, who has absolutely no financial interest in the matter, told me that if it was his house, he would dig outside. Secondly, no other part of the concrete block or floor is wet -- the water is coming in solely from the sleeve. If there truly was an excess amount of water pooling against the outside of the basement, wouldn't the walls and the floor be saturated, too? Of course, the walls were painted by the prior owner. I don't think it was Dry-Lok, but it could still be masking dampness on the block.

  2. Basement_Lurker

    Basement_Lurker One who lurks

    Victoria, BC
    You have a supply line entering your home and a 3" sleeve was used? Wow...I don't even know what to say to that.

    If you have a cinder block wall, then yes sealing it from the outside would be a good idea. If you have a solid concrete footing, then sealing it from outside is not necessary.

    However in either case, you probably need to address your perimeter drainage and landscaping to ensure storm water is being drained off away from your home like it should be.
  3. cacher_chick

    cacher_chick Test, Don't Guess!

    Land of Cheese
    The first question I would want answered is "how deep is it"?

    Many water supply lines are only 4-5 feet below grade and could be hand dug next to a foundation in a couple of hours.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona
    The sleeve is "waterproof" so sealing it on the inside would be almost the same as sealing the outside. One way the water could not get into it, the other way the water could get in, but could not get out, which would be the same thing.
  5. tripletdad

    tripletdad New Member

    Thanks to all who replied.

    The basement is cinder block.
    The main line is about 4 feet below grade, but it's underneath a sidewalk, so a simple hand-dig won't work.
  6. Gary Swart

    Gary Swart In the Trades

    Yakima WA
    Get a can of hydraulic cement. This is a powder that you mix with water. It will harden and stop even running water. Clean out as much of the foam as you can. I would even break that PVC pipe back a bit. Now, read the label carefully on the cement. This stuff has a very short open time. You will wet the area then pack in the cement mixture. You will need rubber gloves as this stuff is heavy with lime and will burn your bare hands. You will not have to fill the entire hole to the outside, but try to get as much depth as possible. I had a similar problem about 15 years ago when I had a new supply line put in. The plumber packed the hole with some kind of silicone product and it leaked. I did the hydraulic cement trick and after 15 years, it's still holding just fine. I've also used this stuff to seal cracks in concrete walls. You have to work fast, probably several small batches will be easier to use than one big one because it sets really fast. I think the brand name I used was Water Plug, and it came in a quart can as I recall.
  7. Ian Gills

    Ian Gills Senior Robin Hood Guy

    I agree with Gary. It's not great to have hydraulic cement in contact with copper but it is probably the best you can do.

    For a slow trickle, which it sounds like you have, it should work wonders.

    If there was a lot of water behind that wall, and a serious drainage problem, tens of gallons would be coming in with a heavy rain, not 2-3. So i'm feeling optimistic.

    Wait for a dry day. And careful not to damage your water pipe as you do any removal of the PVC / white stuff. This is your biggest risk.
    Last edited: Mar 7, 2011
  8. tripletdad

    tripletdad New Member

    Many thanks!
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