I recently noticed that our outside wall has a wet looking spot around the faucet.


I tried looking in the wall at the pipe (from the unfinished basement), but

  1. I couldn’t see very far because the hole is small (maybe could see an inch into the wall) and
  2. I couldn’t see any condensation from what I could see.

Is there anyway to easily diagnose if there is a leak? There is a little bit of clearance around the pipe hole, but not much.

  • What do you mean from the inside? Is there a basement where you can easily access the inside of this concrete wall/foundation?
    – JPhi1618
    Commented Mar 14, 2019 at 15:25
  • @JPhi1618 yes, I'll update Commented Mar 14, 2019 at 15:26
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    Where are you located? I'm curious where there are common basements but no requirement for frost-free hose bibs.
    – JPhi1618
    Commented Mar 14, 2019 at 18:01
  • 1
    @Greg, well if freezes are ever a concern, you might as well replace it with one of these if it does end up needing replacement. They shut the water off inside the house so it's never exposed to the cold outside the walls.
    – JPhi1618
    Commented Mar 14, 2019 at 18:06
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    My first guess would be that someone recently used a hose on the spigot and it sprayed because it wasn't screwed on tightly or the hose washer was defective.
    – Hot Licks
    Commented Mar 15, 2019 at 0:51

4 Answers 4


I have seen copper pipe have small pin holes on several occasions. If your pipe is copper and in contact with the cement this may be the cause. The only way to repair is to replace that section of pipe. When I do this kind of repair I make sure to use thick wall copper because it will last longer than thinwall.

  • 1
    Maybe also due to freeze/thaw cycles of water in the pipe causing a crack? Commented Mar 14, 2019 at 16:26
  • Yes thicker wall and/or wrap it with tape.
    – Joe Fala
    Commented Mar 14, 2019 at 17:38
  • Thanks. We have a warranty that the seller paid for when we bought the house, so we have a plumber scheduled to come check it out. Commented Mar 14, 2019 at 18:05
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    A good time to add a frost proof spigot too.
    – Mazura
    Commented Mar 14, 2019 at 20:20

If you live in a colder weather climate (though your picture indicates that you probably don't due to plants showing at this time of year, and it's not a freeze-proof sillcock), you may have an inside shutoff valve to that outside faucet. If you do have an inside shutoff valve, you could turn that off for a couple days and see if the dampness reduces or disappears. If it does, that would indicate that the faucet plumbing is the culprit. If not, look elsewhere.

Though the dampness all the way up to your siding would indicate that the faucet itself may not be the culprit, especially if you don't see any direct signs of water either on the inside or outside, and dampness might not typically run against gravity that far unless it's really flowing. Is there any plumbing in the walls above that location that might be leaking down? Bathrooms or showers/tubs that may be leaking into the floor and running out? A window that might allow water to get behind the siding and drip down to the foundation? Roof or gutter issue allowing water to run down behind the siding in that location?

  • Hmmm... we are in the mid-Atlantic, USA, so (if it is the pipe that is the problem) we will have the pipe replaced with the frost-proof. Concerning your second paragraph - would there be any reason why the water would form (basically) a circle around the faucet if it were any of the above reasons? I'd have to confirm when I get home, but I do believe that the faucet is located somewhere underneath a set of three windows Commented Mar 15, 2019 at 10:56

If you have access to the inside of the wall put up some cling wrap on the wall. Relatively quickly you should see where water is leaking. You can do this above, under, and to the sides of this faucet. If you wait too long to look at said cling wrap, it could all be wet.

Also it wouldn't hurt to dig a foot or two down on the outside and create a temporary well. If you do this three foot across on the outside and 18" down you can then view what the wet concrete looks like in a week or so. If it looks the same you know that your wet concrete is from an indoor leak for sure. If the wet area keeps traveling down to the well line it could also be excessive water at that spot on the outside being trapped there and wicking upward.

  • Thanks. As I commented above, we scheduled a plumber to come look at it through our home warranty. If it wasn't (or, maybe, if it isn't) covered, I'll use your method and go from there. Commented Mar 14, 2019 at 18:06
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    If a plumber is coming out you might want to dig - takes 5 mins - to prove out the leak.
    – DMoore
    Commented Mar 14, 2019 at 18:09
  • Ahh. Good point! Commented Mar 14, 2019 at 18:11
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    Also you may get charged if there is water coming from outside and you ordered a plumber for something not plumbing related. I would treat anyone coming through a warranty service as someone that you are paying because these companies are very good at making you pay for anything - that is how they make money.
    – DMoore
    Commented Mar 14, 2019 at 18:14
  • Yes, fully expect to pay all of it. Depending on how the problem is diagnosed, the deductible could be high... Commented Mar 15, 2019 at 10:57

Water doesn't flow uphill so I would look in the wall directly above the sill cock

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    Capillary action in concrete can cause water to wick upwards against the force of gravity.
    – Sam
    Commented Mar 14, 2019 at 23:08
  • 1
    Have to down vote this answer as concrete , cement or whatever you call it will wick moisture and is very corrosive to copper. If a very fine spray from a copper pipe, I have seen that travel 2 to 3 times this distance, that's why I suggested thick wall copper. Others have said to wrap I agree , but some of the failures were because of high mineral content and galvanic corrosion.
    – Ed Beal
    Commented Mar 15, 2019 at 1:48

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