The “Invisible” Plumbing Leaks

water damage on home's ceiling. "Finding the invisible leaks"

Some plumbing leaks are easy to find. If you have a leaking faucet or fractured pipe, you’ll be able to see it. Unfortunately, these aren’t the only leaks your home plumbing can spring. Sometimes, it can be hard to know you have a leak at all.

These “invisible” leaks waste money and water, but because you can’t see them, you won’t even know they’re there. Worse, if a leak goes unrepaired, it could spread or even rupture. Not only would that totally compromise your plumbing, it could make for a really expensive repair.

It can pay to know a thing or two about invisible plumbing leaks, which is why we’ve put together this quick primer. Here’s everything you should know about the leaks you can’t see:


leaking faucet

What Are Invisible Leaks?

You can’t see or easily access most of the plumbing in and around your house. All the plumbing pipes in your home run from appliances like sinks and toilets into a single main drain. Then, this drain runs under and out of your home to either a septic tank or public sewer.

Depending on your home’s particular setup, your plumbing might run through walls, floors, yards, or ceilings. Pipes connected to the sewer even run underground. You can’t see that piping the way you can see the pipes in your basement or directly beneath your sink, but it can leak just the same.

“Invisible” leaks are hard to notice, because their effects are often not as apparent as leaking in visible areas. If the main drain under your house springs a hairline fracture, for instance, how would you be able to tell? You’d have to wait until the problem was much more significant before you’d start seeing physical signs.


Water damage on ceiling

Where Are They?

Invisible leaks can occur anywhere where piping can get worn down. Sediment build up, acidic water, overuse, poor construction, water that’s too hot, and just the passage of time can all eventually cause leaks. As the inner walls of your piping wear away, eventually the rush of water through them will find an easier way out than the intended passage through the pipe. The water will rush to and out of this path, leaking out of the pipe. As more water flows, the pipe will widen and the leak will get worse.

Valves, filters, drain lines, joints, and hydrants can all spring “invisible” leaks. Joints where two or more pipes meet are at a particular risk because of the centrifugal force required to guide water from one pipe to another. A lot of invisible leaks tend to occur where a vestigial pipe connects with the main drain leading out of the house. Tree roots can even grow into the main line in your yard, where water is guided into the sewer.


Plumbing technician fixing leak in basement

How Can I Tell If I Have One?

First, wait 20 minutes without using water. Then, find your water meter. It will probably be in front of your house outside, in a covered box. Water meters have a leak indicator built into them. Different kinds of meters have different leak indicators, so look up your brand to find out how yours works.

Your indicator is probably a dial that moves when water is flowing. If the indicator is moving and water isn’t in use, it’s probably because you have a leak. Write down the numbers listed on your leak indicator. Don’t use water for another hour, then check again. If the numbers have changed, you definitely have a leak.

After you confirm you have a leak, turn your water off entirely. Check the leak indicator again. If the leak indicator has stopped moving, the leaking stopped when the water was turned off, and the leak is inside the house. If the indicator is moving or the readings have changed, then the leak is outside of your house.


plumbing detective

How Do I Find Them?

First, check areas where leaking is common. If the leak is inside the house, check the toilets, sinks, faucets, and showerheads. It’s possible the leak is minor enough that you didn’t notice it. Leaking toilets are the most common and most unnoticed leaks.

Even if you can’t see a leak in your pipes, you might be able to hear it. Walk through each room of your house, starting from the lowest level and working your way up. Listen for pressurized whining or dripping. Look for puddles or water staining under the floor or up on the ceiling. Water damage on wood panelling, cabinets, drawers, or wallpaper can all be signs of an “invisible” leak too.

If your leak is outside, check the spigots. Double check to make sure they’re fully tightened. Listen for the sound of dripping or running water. Walk your yard feeling for moist or soft patches, which may have been made by an underground leak.


If you think you’ve found the leak and you can get to it, you could try to fix the problem yourself. Most toilet and faucet leaks can easily be fixed by replacing the O-ring or tightening the fixtures. If you can reach a fractured pipe, you could apply plumber’s tape as a temporary solution until you have the chance to replace the pipe.

If you can’t reach your leak, or if you couldn’t find it, remember that you can always give us a call. We’ve got the experience and the tools to find and fix any plumbing leak, no matter how hidden.

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2 Responses to “The “Invisible” Plumbing Leaks”

  1. Becca Holton

    I can totally believe that leaking toilets are the most unnoticed leaks. My husband and I came across some water damage in our house. It’s pretty bad, so we figure that the leak has been around for a while. Hopefully, a plumber can fix the problem soon.

  2. Emery Jean Chambers

    It sure got my attention when you suggested checking the water meter outside the home to see if there are leaks as it usually has a built-in indicator. Of course, I can give that a try since I know where the water meter is. However, that is as far as I can get since I am always busy with my job. Now that I feel like we have a leak, I think the only thing I can do is check the meter, then hire a professional to look for it. Thank you for sharing.


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