Do you have a water leak that you think might be coming from inside a wall? Stick around because this short guide here will tell you how to find a water leak inside a wall and give you some advice on how to fix it.

Signs of a water leak inside your wall

Water leaks are serious. If they aren’t fixed right away they can damage both your property and your health because moisture helps mold grow.

Unfortunately, you sometimes won’t know you have a water leak until it has already done thousands of dollars worth of damage. So, it’s wise to pay close attention. Here’s how to find a water leak inside a wall:

Signs of a water leak include…

Discolored areas – Leaky water pipes inside walls can cause spots of discoloration to appear.

Mold in areas where you didn’t expect to find it – Mold in damp areas like bathrooms isn’t that surprising. We’ve probably all seen it at some point in our lives. However, black or brown mold elsewhere in your house could be the sign a leaky pipe.

Wet areas – Obviously, a wet wall could mean a leaking pipe. However, keep in mind that the leak might not be directly behind the damp area. The water from leaking pipes can emerge and travel down the pipe before it eventually comes into contact with your drywall.

Peeling paint or wallpaper

Warped or discolored floor or ceiling – Is your drywall, ceiling, or floor warped? Does your floor feel spongy when you walk on it? These are signs of a water leak.

A Musty smell – Just because you don’t see any water damage doesn’t mean it’s not there. Sometimes just the smell is enough to alert you.

Pools of water – Have you determined they aren’t coming from appliances? If so, you might have a leaky water pipe.

Dripping sounds – Do you hear the sound of dripping water when you turn off the faucet or shower? You might have a pipe that’s leaking water.

High water bill – This won’t tell you where a leak is located. However, it’s a strong indication you probably have one.

What you should do if you have a water leak inside a wall

The first thing to do is find out if your plumbing is to blame. (It usually is. However, sometimes it isn’t.)

Here’s how you do that…

Step 1: Turn off all water-using devices in your home.
Step 2: Record the number on your water meter.

How to find your home’s water meter

The most common location for the water meter is in front of your house near the curb. However, if you live in a cold climate it might be located inside your home.

If your meter is outside it will usually be in a concrete box with a cast iron lid that reads ‘’WATER’’. Use a screwdriver or similar tool to carefully remove the lid. As you do this watch out for insects, reptiles, or rodents that might have taken up residence inside.

How to read your water meter

Water meters will either have an analog or a digital display.

An analog water meter will have a sweep hand and the numbers clearly displayed. The water use is measured either in gallons or cubic feet.

A digital water meter needs light in order to work (shine a flashlight on it) and the display switches back and forth between the rate of flow (how many gallons per minute are flowing through the meter) and the meter read (how many gallons or cubic feet have been used). Make sure you record the meter read number.

Step 3: Wait at least 3 hours. Do not use any water during this time.

Step 4: Check the number on the water meter and compare it to the number you wrote down in Step 2. If it has moved, you have a leak somewhere in your plumbing. If it hasn’t, the water could be coming from a leak in your roof or walls.

In that case…

Check to make sure your gutters and downspouts aren’t clogged with leaves. If water gets in and can’t find a way out it will eventually start seeping into your home.

If you’ve performed the water meter test and your gutters and downspouts are free from debris…

Call a professional to come out and check for leaks in your foundation or foundation walls.

Tests that will pinpoint a water leak inside a wall

Moisture meter – You can buy or rent a moisture meter at a hardware store and use it to pinpoint the area of the leak. Point it at various areas of the wall until you find the spot that produces the highest reading. That’s the one nearest the leak. If you call a professional to come out and check for leaks they will bring along one of these devices.

Infrared camera – You can also use an infrared camera to detect cold areas in a wall. The wettest areas of a wall will be the coldest and will show up as blue or purple on the camera. This is another device commonly used by plumbing professionals to detect water leaks inside walls.

Cut into your drywall – Because this test is invasive, it’s definitely the last resort option. Basically, it involves cutting into your drywall in order to take a look around. When deciding where to cut keep in mind that the area of visible water damage might not be where the leak is located. Water can drip down the side of a pipe for some distance before it eventually starts coming into contact with your drywall.

Before you take the drastic step of cutting into your drywall, we advise you to contact a plumbing professional. A qualified and competent contractor will only do this as a last resort.

We’re Sewer Pros, a licensed and insured sewer repair and replacement contractor serving customers in both Los Angeles and Orange counties. Get in touch today by calling (310) 208-0525 and find out how trenchless repair methods can save you both time and money!