7 Signs Your Roof Has a Leak and What to Do About It

A leaking roof can cause serious damage to your home—leading to costly repairs. That's why it's important to spot potential issues early and fix them right away. Here are the key signs that your roof has a leak, along with common causes and how to address them.

The Most Common Signs You Have a Roof Leak 

Watch for these telltale signs of a roof leak to minimize damage, repair costs, and potential health issues.

1. Water Stains on Walls and Ceilings

Do you see yellow, brown, or faint stains on your ceiling and walls? It’s likely due to a leaky roof. These water spots are often located in the center of the room, but may be in the corners or along an exterior wall. 

If water has reached your walls and ceilings, it's time to repair the issue to prevent mold, rotted framing, and damaged ceilings. Contact a local roof repair pro to find the trouble spot and repair it thoroughly.

"Water generally will flow across the top of the sheetrock or plaster until it finds the lowest point, and that is where the water will appear," says Ami Feller, owner of Roofer Chicks in New Braunfels, TX. "Often that means the water comes into light fixtures, because the weight of the fixture slightly pulls down the drywall. If this happens, no need to panic. Just turn off the fixture to stop the flow of electricity and call a professional."

2. Mold on Exterior Walls

If you have mold growing on an exterior wall, you probably have a roof leak. Use a measuring tape to determine how far the mold spot is from the corner or a door. Measure the same distance on the outside of the wall to look for the culprit. If the ground slopes toward the house or a downspout is emptying near the wall, you’ve likely found the root of the problem. A roofer can help you make a plan to fix the issue.

3. Dripping

If you see or hear dripping in your attic or anywhere else in your house, a roof leak is likely to blame. Even if the leak isn't always present, you should check it out to ensure it doesn't get worse. You may have an ice dam that formed when ice and snow froze and thawed. Even intermittent leaks can cause big damage.

Common Culprits of a Roof Leak

Beyond the giveaway signs of a leaky roof, watch for other possible causes of roof leaks. If you spot these issues, it’s time to investigate further and repair your roof. 

4. Cracked, Damaged, or Missing Shingles 

If your shingles are compromised, water can enter your home. If you notice any missing or broken shingles on your roof, ensure you repair or replace them as quickly as possible.

5. Damaged or Missing Flashing

If you spot damaged or missing metal flashing around the edges of your vents, roof, or chimney, water can leak into your home. If your step flashing rusts or becomes loose, water seeps inside. 

Damaged flashing is often due to drying and cracking, storms, and high winds. You can sometimes do a roof repair on these spots without replacing your entire roof, but you'll want an expert to take a look.

"Chimneys are a very common source for roof leaks; I would definitely recommend hiring a professional to redo the flashing if that is the leak source," says Feller. "Ensure the contractor you choose is knowledgeable on flashing repairs and provides a warranty for the work."

6. Puddle of Water

If you notice pools of water on your roof, it’s worth having a roofing expert check it out. If you have a flat roof especially, water can sometimes create puddles in certain areas.

Watch for leaks by looking inside your home near where the puddle of water is located. Take a close look around the potential problem area, as the leak might not occur directly below the pool of water.

7. Damaged Plumbing Vent Boots

If your plumbing vent (usually a white pipe sticking out of your roof) is torn or rotted, water can travel down the outside of the pipe and into your house. Replace your roof boot if it's damaged. If nails are missing at the base, but the boot looks fine, replace the nails.

Pro Tip: Be sure to cover any exposed nails with roofing sealant to prevent them from oxidizing, which will eventually lead to a leak when the faster rusts out.

Other Signs of Roof Issues

Beyond roof damage, there can be other issues causing water damage or condensation in your home. Keep an eye out for these problems and take care of them as soon as you spot them. 

• Clogged Soffit Vents: If the soffit vents in your attic are dirty or clogged, moisture can build up and mold can grow in your roof’s framing. 

• Shiners: Shiners are nails on the underside of your roof that missed a framing member. If these nails look frosty or white (best to check on a cold evening), it means moisture is condensing on the nails.

• Rusted Gutters: Leaks can form if your gutters have rusty spots or seams. You can repair the gutter by removing rust with a wire brush, scraping the tar out with a putty knife, and resealing with repair tape. 

• Debris in Downspouts: If you notice dirt and debris in your downspouts, you may have issues higher up in your roofing or flashing. 

Pro Tip: If you do find a roof leak that’s caused interior repairs, and you have the leak fixed, you should wait for another heavy rain (or two). That way, you can make sure that the leak is completely fixed before making any costly interior repairs.