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Main feed water pipe corrosion through basement wall

T. J.
T. J. Member Posts: 47
I have what looks like the sign of a leak at the first elbow of my main city water line coming into my house through the cinder block basement wall. My first question is how serious is this (do I need a plumber over here now)? Secondly, how did this happen, i.e., is it rotting from the inside or from the outside (wet inside the basement wall)? Finally, how intensive (nee, expensive) would the fix be?

The first pic is a close-up of the pipe, the second is after some cleaning. Thanks for any advice.


  • ratio
    ratio Member Posts: 3,544
    It's only going to get worse, not better. Time to get estimates from a few plumbers on replacing it.

    I had something similar (old galvanized line) that started leaking. I made the mistake of calling the water department to ask them what to do. They came out, looked at it & said 'Yup, you got a leak, here's your 48 hour disconnect notice, unless you get it repaired before then.' In case you're wondering, I'm still a little salty about that.

  • Intplm.
    Intplm. Member Posts: 1,603
    After the cleaning shown in your second pic, things look a bit better. It also looks like the there is insulation around the pipe. If there is insulation then that's a real good thing.
    Masonry and copper do not always go well together. When they are in contact for a long period of time the concrete can eat away at the copper.

    However, It does not look like you have that problem. At least not in the "emergency" scents. The insulation around the pipe should be protecting the water main.
    The green color is at the end of the pipe and where the insulation ends. So a little chemical reaction has taken place there.

    Have seen many like this (in my own home right now even)
    I would not worry much about it unless you see more green and white coloring that starts to look like a combination of broccoli and cauliflower growing on the pipe. That is a sign of a very slow growth leak.

    To me, your pipe looks good to the point that you give it a look now and again as you would in your weekly care of your home.
    As a common precaution, you should know how to turn the water off to your home both inside and at the the streets curb box. Knowing the streets curb box location is great to help your water company shut the water off incase of a street to home emergency.

    As for pricing. We do not discuss pricing on this sight. There are to many variables to consider.
    EBEBRATT-Ed Member Posts: 14,495
    @T. J. It looks ok. Looks like they insulated around the pipe to protect it from the concrete
    JUGHNE Member Posts: 10,898
    Intplm's suggestion is good.
    It varies with water suppliers but some allow the HO to operate the curb stop. Here the curb stop is property of the HO. The tools are inexpensive. I would test it now to insure it is operable.....and locatable. The access cover could be below ground maybe 1 foot.
    I try to describe the location and even a simple map info is drawn on the main breaker panel. For example, from the NE corner of house 20' east and 5' north. It could be visible now, but now when covered with snow.
  • Fred
    Fred Member Posts: 8,541
    Doesn't look like corrosion to me. The green color may be the result of condensation from a temp change from inside to outside? It's too even across the elbow and I don't see any point where it is concentrated or where a pinhole may be developing. That elbow looks like it may even be brass???
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,137
    Hello, Any chance the moisture came through the wall from the outside? The insulation might have given water a path to take.
    Yours, Larry
  • T. J.
    T. J. Member Posts: 47
    Thanks all for your comments. I feel a bit better about this, and will watch it, but I'm still leaning toward calling a plumber to confirm as while it looks like there's insulation around the pipe, it's rock hard. Could it be they cemented around the pipe and cinder block?

    As for the city water shut-off, I believe there is a small iron disc in the sidewalk in front of my house that is the water shut-off. However, I'm afraid to contact the city to ask if I'm allowed to shut it off myself after hearing ratio's comments above.

    Finally, as for Larry's comment regarding moisture, I'm sure there is a ton in the wall. As you can see in the pics, when I moved in the house in '05, I had a perimeter drain installed to deal with the wet basement.
  • Intplm.
    Intplm. Member Posts: 1,603
    Don't be afraid to call the water department.
    Just ask them what they need from you concerning when you would need the water shut off to your home. They should explain the policy as to who is and is not allowed to turn the water off.
    If this is that much of a worry, certainly get a in person, second opinion. If nothing else that opinion should offer some peace of mind.
  • T. J.
    T. J. Member Posts: 47
    I'm just posting an update now that a few months have past. In June I had cleaned up the green stains on the city water feed coming out of my foundation wall (above) and attached are pics of what it looks like today, four months later....

    Regarding shutting off the water, my curb stop is visible on my driveway apron and I did contact my water department asking if I'm able to shut it off myself in case of emergency, but they replied that they are the only ones who are allowed to access it.

    Thanks for your replies,
    T. J.
  • mattmia2
    mattmia2 Member Posts: 8,834
    So the moisture could be a leak in the pipe or a leak through the wall or condensation on the pipe which is likely to be below the dewpoint from the cold water.

    Moisture from sweating combined with the salts in the concrete could be making the green colored copper salt.
  • mattmia2
    mattmia2 Member Posts: 8,834
    I don't see anything isolating it from the masonry but it is unclear from the picture. It appears to just have mortar or concrete around it and some old yellow paint or something.
  • T. J.
    T. J. Member Posts: 47
    Mattmia, there's some sort of patch work around the pipe. Not sure if it's mortar or some sort of insulation (the reason for the yellow?), But it's not foam because it's hard.

    So, I'm hoping it's not a leak and just some surface copper corrosion from condensation in the wall.