How to tell if there is water damage in a wall?

Author: Maudie Moore DVM  |  Last update: Tuesday, December 2, 2025

Signs of Water Leaks in Walls
  1. Damp or discolored drywall.
  2. Peeling paint or wallpaper on your wall.
  3. A warped or stained wall.
  4. A buckle, crack, or water stain on drywall ceiling or your floor.
  5. Pools of water on the floor near walls or drips from the ceiling.
  6. A musty smell.

How to check for water damage in a wall?

If the wall sinks inward or becomes depressed in some way, you likely have water damage on the inside, even if the exterior appears normal. Discoloration, often appearing in the form of streaks that can be short or quite long, running down the wall in affected areas. Water rings, usually a light brown color.

What does water damage on a wall look like?

Discoloration: One of the most obvious signs of water damage in walls is discoloration. If you notice any yellow, brown, or dark stains on your walls or ceiling, it could be a sign of water damage. Peeling or bubbling paint or wallpaper: Water damage can cause paint or wallpaper to bubble, peel, or become discolored.

How do you tell if there is moisture behind a wall?

You can often detect moisture issues by looking for water stains, discoloration, or visible mold. Other signs include peeling paint, bubbling wallpaper, and soft or warped drywall, which can signal moisture buildup.

How to tell if wet drywall needs to be replaced?

Mold or Bacterial Contamination: Any drywall exposed to contaminated water or showing signs of Mold must be replaced. Compromised Structural Integrity: If drywall starts to crack, crumble, or sag after drying, it is no longer structurally sound and should be removed.

Here's a Tip for Validating Moisture Within Walls

Will mold always grow on wet drywall?

No mold doesn't always grow after a leak. If the temperature isn't right or if the leak is properly dealt with quickly, there's a chance that mold spores won't be able to take root or grow.

How do you know if there is water behind drywall?

Signs of a Water Leak Behind Walls
  1. Peeling wallpaper or paint.
  2. Cracks on the ceiling or water stains on the walls.
  3. Cracked or bucked floors.
  4. Musty or moldy smell in the room. This usually persists even if you improve the ventilation in that room.
  5. Presence of mold and mildew, especially on walls, ceilings, and floors.

How to find a water leak inside a wall without?

These include:
  1. Discoloration on Walls. One of the more obvious signs that you may have a water leak in your wall is discoloration or staining on the walls. ...
  2. Peeling Paint or Wallpaper. ...
  3. Musty Odors. ...
  4. Rising Water Bills. ...
  5. Get a Moisture Meter. ...
  6. Use an Infrared Camera. ...
  7. Cut Into Your Drywall.

Will water in a wall dry out?

Yes, damp plaster can dry out, but the drying time depends on several factors, such as the extent of the dampness, the type of plaster, the temperature and humidity levels, and the amount of air circulation in the affected area.

Is there an app to detect moisture in walls?

The moisture mapping app records wall and concrete floor moisture reading details in all areas, making it easy for users to get the details they need quickly and easily from any mobile device.

Is water damage in walls covered by insurance?

Under most standard home insurance policies, if water damage occurs suddenly or accidentally from a source inside your home, such as a busted pipe, it will likely be covered by your homeowners insurance. If the water comes from outside your home, it will not be covered by your standard policy.

How to test for water damage?

Inspect for moist, damp areas on ceilings, walls and floors. Check for discoloration on ceilings and walls, as well as other irregularities (sagging, bubbling, peeling, blistering, bubbling, cracking). Search for signs of mold, which appears as clustered black or brown dots in its early stages.

How do I know if I need new drywall?

Sagging Or Warped Walls

Sagging or bulging drywall usually indicates water damage or structural issues. This situation clearly shows that your drywall needs replacement to keep your home safe.

What does water damage behind drywall look like?

Look for discoloration, which often shows up as streaks from the ceiling. These streaks are usually brown and mean water has gotten into the walls. Mold is another clear sign of damage. It looks like black, green, or white spots and loves damp places.

How do plumbers detect leaks in walls?

Thermal imaging can be used to detect moisture in ceilings, flat roofs, behind walls and under floors. Using thermal imaging cameras is an effective way to look at large areas quickly, and causes minimum disruption and no damage to your property.

How do they fix water damage in walls?

Steps To Repairing Water Damage
  1. Clean The Area. Before you start a project like this, give the water damaged area a good clean. ...
  2. Clear And Scrape Any Flaking In The Area. ...
  3. Cover Water Damaged Area With A Peel-Stop / Sealer Binder. ...
  4. Apply Filler. ...
  5. Sand Surface. ...
  6. Apply Water-based Primer / Sealer. ...
  7. Apply Paint.

How long does it take for mold to grow on wet drywall?

mildew and mold will develop within 24-48 hours of water exposure. Even worse, it will continue to grow until steps are taken to eliminate the source of moisture, and effectively deal with the mold problem. Use the diagram on the facing page to assess the extent of mold in your home.

What draws moisture out of walls?

Use fans to move air around the damp walls. Also use dehumidifiers, which can help remove moisture from the air and walls. Professionals use tools like moisture meters, infrared imaging devices, dehumidifiers and heavy-duty fans. That ensures the walls are truly dry before further repair, painting or refinishing.

What happens if water gets in your walls?

One of the biggest concerns when water gets in your walls is the potential for mold and microbial growth. These harmful microorganisms thrive in damp, dark environments, and your walls provide an ideal breeding ground. Mold can lead to health issues and extensive property damage if not addressed promptly.

How do you know if your water is leaking behind the wall?

Step 1: Look for Visible Signs of Water Damage

Some common signs include wet walls, wet spots on floors or ceilings, peeling or bubbling paint or wallpaper, sagging walls or ceilings, discolored patches on walls or ceilings, and a musty smell.

Who to call for water damage in a wall?

Interior Walls & Lower Ceilings – Plumber or HVAC Contractor.

How do you check for water pipes behind walls?

Pipe finders are designed to identify where electrical cables or gas and water pipes are located inside a wall. This is especially helpful if piping isn't visible or when doing building work on a property you're unfamiliar with.

How to test for water damage in walls?

Use an Infrared Camera

If you cannot see the more obvious signs like paint bubbling on the wall water damage can be difficult to confirm. An infrared camera offers a quick and non-intrusive solution to detect a water leak in your wall.

Does insurance cover water damage?

Most home insurance policies cover accidental and sudden damage caused by water. For example, a burst pipe that caused damage to a wall or floor would be covered. However, a gradual leak or seepage due to poor maintenance wouldn't be covered. Also, water damage insurance does not cover negligence.

How much does it cost to fix a leak behind a wall?

Fixing an exposed pipe in a crawl space or basement is $150 while repairing a leaky pipe inside a wall starts at $150 and can go up to $350 or more. A pipe in the wall behind a kitchen cabinet will cost $500; if the faulty pipe is in a ceiling, it can cost $700 to $2,500.

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