How to Find and Repair Water Leaking in the Wall

By: Diana Rodriguez-Zaba
Updated on: March 8, 2022

It doesn’t set off alarms. You can’t hear it or see it.

Left undetected, it can cause serious damage to sheetrock and even affect floors and ceilings. A slow water leak hidden inside the walls of your home creates a damp environment that breeds mold and rots wood.

As well as you stay ahead of repairs around the house, do you know how to detect water leakage in walls?

Through our water removal services here in Chicago, we see so many homeowner headaches caused by water leaks inside walls. When you know what to look for, it’s easier to spot a hidden water leakage problem and fix the problem. 

Let’s get started.

12 Warning Signs of Water Leakage Behind the Wall 

peeling paint water damage

When a frozen pipe bursts or a drain backs up, you know something’s wrong right away. You quickly identify the source, pinpoint the problem and take care of repairs.

When a slow leak starts inside your home’s walls, it doesn’t attract attention, but it does leave solid clues. If you know how to detect water leakage in walls, you can minimize potentially serious damage.

Be on the lookout for these 12 signs of water leaks behind your drywall.

1. Persistent Musty Odors

As water slowly drips from a leaky pipe inside the wall, flooring and sheetrock stay damp and develop an odor similar to wet cardboard. It generates a musty smell that can help you find hidden leaks.

Power Tip: Structural materials can retain water like a sponge, so peculiar smells may be your only sign of leaks behind the walls.

2. Mold in Unusual Areas

Mold usually grows in wet areas like kitchens, baths and laundry rooms. If you spot the stuff on walls or baseboards in other rooms of the house, it’s a good indicator of undetected water leaks.

Power Tip: Any patches of mold larger than a few square feet should always be taken care of by a restoration company that provides certified mold removal and remediation.

3. Stains That Grow

When mold thrives around a leaky pipe, it sometimes takes hold on the inside surface of the affected wall. A growing stain on otherwise clean sheetrock is often your sign of a hidden plumbing problem.

4. Peeling or Bubbling Wallpaper / Paint

This clue is easy to miss in rooms that don’t get much use. When you see wallpaper separating along seams or paint bubbling or flaking off the wall, blame sheetrock that stays wet because of an undetected leak.

5. Slowly Warping Sheetrock

Over time, sheetrock wicks up moisture from a slow leak, and that can cause the wall to develop bends and curves. Warped sheetrock is a sure sign of a slow water leak.

Power Tip: Wet walls that sag or curve outward indicate structural damage that can cause saturated drywall to buckle and collapse.

6. Buckled Ceilings and Stained Floors

If ceilings or floors in bathrooms, kitchens or laundry areas develop structural problems, don’t rule out constant damp inside the walls. Wet sheetrock can affect adjacent framing, flooring and ceilings.

7. Wet Blotches

Wet spots are sure signs of water damage in walls, but they don’t always pinpoint the problem’s location. Water can travel down a pipe and cause wet blotches on the wall below the leak.

8. Odd Discoloration

As a leak moves further down inside the wall, overlooked wet spots eventually dry. They leave behind splotches that appear lighter than surrounding drywall or wall paper.

9. Wet Floors

This sign is obvious on kitchen floors, but it’s not as noticeable in carpeted rooms. If an area of carpeting appears darker next to a wall, touch the fibers. If they’re damp, you probably have a wall leak.

Power Tip: Wet flooring that feels warm underfoot is often caused by hot water pipes leaking inside the walls.

10. Dripping Sounds

Water running down inside walls often makes a dripping sound. You’ll usually hear the plinking noise after turning off a faucet in the sink, tub or shower. You may also notice audible clues after flushing the toilet.

11. Damp Window Sills

Damp windows sills and frames may indicate leaking pipes inside the wall. As water from a leak moves downward, it collects on frame edges, sill surfaces and undersides.

12. Increased Water Bills

According to the EPA, a single person uses more than 80 gallons of water a day. Most families typically go through 300 gallons a day. A wall leak can quickly run those numbers up and cause a spike in your monthly water bill.

Keep in mind that leaks behind a wall can cause serious damages that you don’t see. For example:

  • Water-damaged drywall and wood framing become structurally unstable.
  • Mold inside wet walls releases unhealthy spores and compromises indoor air quality.
  • The damp creates a breeding ground for pests, such as cockroaches, silverfish and termites.

Testing Your Suspicions

water meter
A water meter test can help you determine if there’s a leak in your house.

Figuring out how to detect water leakage in walls takes a little investigative work. If the clues add up and you want more evidence of a hidden leak, use your home’s water meter to test your suspicions by following these simple steps.

  • Make sure all faucets and appliances in the house are turned off.
  • Take a look at your home’s water meter, and note the usage numbers.
  • Don’t run any water inside or out for at least three hours.
  • Check the usage numbers on the meter again for any changes.
  • An increase in the readout means you have a leak somewhere in the house.

Tools That Help Detect Water Leaks in Walls

water damage moisture reader

Cutting into drywall to locate a leak doesn’t always give you access to the problem. Water could be dripping from a pipe several feet above the wet spot. Reduce the guesswork with these leak-detection tools.

  • Moisture Meter – This device analyzes moisture content in all types of materials. Locate a leak by placing the meter directly against the wall. Move it around, checking four or five different points. The spot that gives you the highest reading is nearest to the hidden leak.
  • Infrared Camera – An infrared camera detects moisture inside walls through an optical system that measures infrared energy and surface temperature. As you move the camera around a suspected area, a cooler temperature reading helps pinpoint the location of the leak inside the wall.

You can buy or rent both tools at most home improvement centers.

Moisture meters and infrared cameras are just two examples of the advanced equipment used by restoration professionals like ServiceMaster Restoration by Zaba to detect hidden wall leaks.

How to Fix Water Leakage From the Wall in 8 Steps

Knowing what to do if your wall is leaking water saves cleanup time and reduces the chance of serious water damage.

1. Confirm the Wall Leak

Turn off your home’s main water supply, and make a note of the meter reading. Wait several hours, and check the meter again.

If the reading goes up, the leak is inside the house. If the numbers don’t change, the leak behind your home’s walls is probably caused by:

  • Clogged gutters or drain spouts

  • Loose shingles and roof flashing

  • Clogged window weep holes

  • Exterior wall damage or cracks

2. Leave the Water Off

Once you’re sure the plumbing leak is inside the walls, leave the water off while you work. Open up faucets inside the house to drain as much water as possible from pipes before you begin repairs.

3. Zero In on the Leak

Use your moisture meter or infrared camera to narrow down the wettest area on the wall. If you have access to both tools, use them together to fine-tune your inspection.

Power Tip: A headlamp can be a big help when you’re working in the attic, a closet or pantry.

4. Repair the Pipe

Stop the leak with a patch kit, but understand that the fix may be temporary. Double-check the area over the next few days to make sure you’ve stopped the wall leak.

5. Mop and Dry

Mop up as much water as possible. If you have a wet vac, use it to remove residual water. Start the drying process by setting up large fans and a dehumidifier. It may take several days to completely dry wet walls and floors.

6. Clean All Surfaces

Scrub affected areas with warm water and a low-sudsing dish soap. Disinfect non-porous surfaces with a mix of bleach and water. Speed up drying time by keeping the fans and dehumidifier running 24/7.

7. Take Care of Mold

Clean up mold on drywall and other affected surfaces right away. Otherwise, airborne mold spores quickly contaminate air ducts and spread through the house. Stay safe by wearing heavy gloves, disposable overalls, a respirator and wrap-around goggles.

Power Tip: Never risk your health by trying to clean up mold on areas measuring more than 3 square feet.

8. Let Pros Finish the Job

Let a water damage specialist like ServiceMaster by Zaba here in Chicago, IL take care of permanent repairs and drywall restoration.

When you call in a company that specializes in this kind of work, you:

  • Leave the entire job in the hands of certified technicians
  • Count on advanced repair, cleaning and restoration techniques
  • Greatly reduce cleanup and drying time
  • Know mold removal and remediation are taken care of
  • Don’t navigate insurance paperwork by yourself

How to Prevent Hidden Wall Leaks

While it’s always best to let a restoration professional handle repairs and remediation, here are important steps you should also take to minimize damage.

  • Keep Gutters Clear – Fixing a wall leaking from rain water might start with cleaning out the gutters. When they’re clogged, heavy rain spills down your home’s exterior and can seep into the walls inside.
  • Keep an Eye on the Roof – Water leaking in walls when it rains can indicate problems on the roof. Make regular roof inspections part of your water leak prevention plans. Immediately replace bad shingles or flashing.
  • Inspect Window Weep Holes – When these small holes along the bottom edges of storm window frames become clogged, they can push water into the walls. Use a toothpick or stiff toothbrush to keep them clear.
  • Replace Old Insulation – Insulation in the walls protects your home’s plumbing from freezing weather. Upgrading older insulation minimizes the chances of leaks from frozen burst pipes inside walls.
  • Check Washing Machine Connections – Over time, washing machine hose connections to supply pipes behind the walls begin to wear out. Check them regularly for signs of corrosion, and replace damaged parts as needed.
  • Have the Plumbing Inspected – Copper and iron plumbing systems tend to corrode and leak inside walls. Keep plumbing inspections on your list of annual maintenance routines. This is especially important if you live in an older home.
  • Maintain HVAC Equipment – Schedule professional HVAC maintenance twice a year. This service includes checking the condition of the drip pan and condensate lines. These biannual inspections help prevent serious ceiling and wall leaks.
  • Monitor Your Water Pressure – If the water pressure in your home is unnecessarily high, it puts additional stress on pipes and connections. Check the water pressure on a hose spigot near your home’s main water supply line several times a year.

How Much Does It Cost to Repair a Water Leak in the Wall?

water leakage expert

Depending on the extent of damage from a water leak in the wall, repair costs can run between $350 and $2,000 or more.

In addition to cleanup, water remediation and restoration, the cost can also include plumbing repairs and mold removal. A reputable water damage company will give you a detailed estimate that outlines the leak repair process.

Need Wall Leakage Repair in Chicago, IL or Suburbs? We Can Help!

Watching out for hidden leaks can help keep wall leakage repair jobs small and manageable. It also decreases the chances of unhealthy mold growth and pest infestations behind the walls of your home. Stay alert for the signs we’ve outlined above, and be ready to fix it yourself with our complete guide to DIY wall leak repair.

If the repairs are more than you want to take care of by yourself, give us a call right away. We’re ready to respond with a full line of water damage restoration services across Chicago and the suburbs.

When you need help solving homeowners’ headaches, you can count on ServiceMaster Restoration by Zaba. Call us now for help: 773-647-1985

Does a water leak behind a wall always mean there’s mold?

In most cases, yes. Once drywall and insulation become wet, mold sets in and begins to grow within 24 hours. Undetected, it quickly spreads through the dark, humid environment.

Why does water leak into walls when it rains?

Rain that leaks through a roof can seep down into framing and drywall. Overflowing gutters and bad seals around windows are also sources of rain water inside walls.

Where can I buy a wall water leak detector?

Look for moisture meters online or at the home improvement store. The tools are available in several models, and most can detect dampness in a range of building materials.