How to apply caulk to seal water pipe through basement wall

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by goshenplumber, Jul 8, 2013.

  1. goshenplumber

    goshenplumber New Member

    Messages:
    27
    Location:
    WV
    My 1 inch plastic water pipe from the utility comes through the basement wall inside a 10 foot long plastic sleeve which runs underneath the front porch. The sleeve runs downhill from the front of the porch to where it enters the basement wall. In the basement, the installers caulked the space between the inside of the sleeve and the outside of the plastic water pipe to prevent any water in the plastic sleeve from leaking into the basement. I do not know what type of caulk was used. The caulk seal lasted for 10 years without any problem.

    Recently I had plumbing work done in the basement and I had to re-caulk the space between sleeve and plastic water pipe. Apparently my caulking job was not good enough because after 6 weeks, the seal started to leak - water in the sleeve was dripping into the basement. I used GE Silicone II 100% silicone caulk that I put on in thin layers. See the attached photo.

    Questions:
    (1) Is GE Silicone II 100% silicone caulk the proper material to seal between the sleeve and plastic water pipe?
    (2) Is there some technique I should use when applying the caulk to ensure that the caulk adheres to the plastic water pipe so that the seal does not break over time?

    Thank you.

    How to seal water pipe through basement wall - #2.jpg
  2. Smooky

    Smooky Member

    Messages:
    598
    Location:
    NC
    Was the pipe caulked on the outside where the plastic pipe enters the PVC sleeve? Sealing that end up good may prevent water from getting in there in the first place. If it is sealed good on the outside the problem should stop. … If that is not the problem you might have a slow leak where the pack joint attaches to the plastic pipe.
  3. goshenplumber

    goshenplumber New Member

    Messages:
    27
    Location:
    WV
    Thank you for responding!!

    Unfortunately the pipe was not caulked on the outside. I could dig down and seal it, but for reasons that I can't go into in this post, I'd rather not. Since the previous caulking job lasted for 10 years (!!), I should also be able to seal the PVC sleeve from the inside. I don't know why my work does not last. My guess is that using silicone caulk is not the proper material.

    Also I was able to confirm that the leak is from the PVC seal and not from the plastic to copper connector. Is this what you meant by "pack joint attaches to the plastic pipe"?
  4. Smooky

    Smooky Member

    Messages:
    598
    Location:
    NC
    If the pipe is sloped down to the basement, The rain water will follow the pipe and fill the PVC sleeve. Then you may have several foot of head pressure on your caulk joint in the basement. You could dig out the caulk and re-do it. This time use more and pack it up into the sleeve as far as possible. Wedge the plastic pipe so it is not touching the sleeve in the center of the pipe or use some type of spacer to create an annular space around the plastic pipe. Caulk the annular space thoroughly.
    A pack Joint fitting is what you call a Plastic pipe to copper pipe connector.

    http://www.fordmeterbox.com/documents/flyers/pack_joints.pdf
  5. seekeruno

    seekeruno New Member

    Messages:
    1
    Location:
    Michigan
    What I would do.

    Remove all the silicone that I could by cutting it out. Sand the plastic and pipe clean of all other materials to get a good bonding surface. Purchase Titebond weathermaster sealant. There is one for metal that bonds to most other surfaces. But the general one should work for what you have( bonds to plastic and metal). Has UV protection, good flex, will not crack, just have to make sure you get a good bond. Can be purchased at grainers , some Lowe's, I would go to their web site and look at their products I have use the metal sealant line and have had great results with it. I buy from my metal roofing company. Large selection of colors too.
    Good Luck

  6. JHZR2

    JHZR2 New Member

    Messages:
    20
    Location:
    NJ
    Interesting. My gas pipe into the house is sloped upwards, and has a concentric profile like that. It leaked last night under the heavy downpours - had never seen that before. Mine is metal in metal. No idea what is clogged in the gap, but surely it is quite old.
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