15 Signs of a Water Leak and What to Do About It

April 29, 2024

Many homeowners fail to spot water leaks until it’s too late and the water buildup has caused structural issues, mold growth, or costly water bills. Knowing the signs of a water leak can help you catch problems early and avoid major repairs.

This guide will walk you through the common signs of a water leak in your home, how to pinpoint the source, and when to call a professional. 

Need expert help? Brothers provides trusted leak detection and plumbing repair services.

15 Signs of a Water Leak in Your Home

Some water leaks are obvious, like a dripping faucet or a burst pipe. Others are hidden, slowly causing damage behind walls, under the floor, or in your foundation. Knowing how to find a water leak before it’s too late can help prevent costly repairs and high water bills.

1. An Unexplained Increase in Your Water Bill

If your water bill suddenly spikes but your water habits haven’t changed, you could have a hidden leak in your plumbing system. Signs of a water leak aren’t always obvious—water may escape behind walls, under floors, or underground. If you can’t find the source, our professional plumbers use advanced leak detection tools to pinpoint the issue and prevent costly damage.

2. Mold or Mildew Growth

Mold and mildew thrive in damp, humid environments, making them one of the most common signs of a water leak somewhere in your pipe system. A professional plumbing check is the best way to find the source of the leak and get it taken care of quickly.

3. Water Stains on Walls, Ceilings, or Floors

Water stains often signal a water leak in your home, whether from a plumbing or roof leak. If you see discoloration or dark spots on ceilings, floors, or walls, don’t ignore them. A professional inspection can confirm if the leak is active and needs repair.

4. Peeling or Bubbling Paint and Wallpaper

Moisture buildup behind walls can cause paint to peel or wallpaper to bubble. This is often a sign of a water leak in your home. If you notice unexplained blemishes on your walls, it’s best to have a professional check for leaks before the problem worsens.

5. Musty Odors in Certain Areas

A persistent musty or mildew-like smell could mean hidden moisture from a water leak in your home. Leaks that go unnoticed can lead to mold growth behind walls or under floors. If the smell lingers, it’s time to have a professional locate and fix the issue.

6. Sounds of Running Water

If you hear water running when no taps, appliances, or toilets are in use, you may have a hidden leak. Listen for dripping, hissing, or rushing water behind walls or under floors. If you hear something, turn off the water and check your meter for movement. 

7. Low Water Pressure

A sudden drop in water pressure, especially in multiple fixtures, could indicate a water leak, blockage, or other issue. Leaks divert water away from your pipes, reducing flow to faucets and showers. If you notice weaker pressure, call a Brothers plumber to check your plumbing for issues.

8. Warm or Damp Spots on Floors

If you feel unexpected warmth or dampness on your floors, it could be a sign of a water leak. Hot water line leaks can create warm spots, while hidden pipe leaks may cause damp or spongy flooring. A professional inspection can pinpoint the source.

9. Soft Spots of Warping in Wood Floors

Wood flooring that buckles, warps, or feels soft underfoot may indicate prolonged water exposure. Hidden leaks can seep into the subflooring, causing structural damage over time. Finding a water leak is important to prevent extensive repairs if you notice changes in your floors.

10. Cracks in the Foundation or Walls

While small cracks can appear over time, sudden or widening cracks in your foundation or walls may indicate a hidden water leak in your home. Leaking pipes can weaken structural materials, leading to shifting and cracks. If you notice worsening damage, it’s best to investigate the cause.

11. Pooling Water Around Appliances

You may have a slow leak if you find water collecting around your washing machine, dishwasher, or water heater. Even small drips can lead to bigger problems over time. Regularly checking these appliances can help ensure you spot a water leak before it causes major damage.

12. Soggy Patches in the Yard

Unexpected wet or muddy spots in your yard—especially when it hasn’t rained—could indicate an underground pipe leak. A sudden increase in plant growth in one area can also be a clue. If you suspect an issue, a plumber can check for leaks in your outdoor plumbing.

13. Water Meter Running When No Water Is in Use

One of the easiest ways to find a water leak is by checking your water meter. Turn off all faucets and water-dependent appliances, then see if the meter is still moving. If it is, you likely have a hidden leak that needs professional attention.

14. Increased Humidity Inside the Home

A hidden water leak in your home can raise indoor humidity levels, making rooms feel damp or stuffy. Excess moisture can also lead to mold, mildew, and window condensation. It’s worth checking for leaks behind walls or under floors if you notice persistent humidity.

15. Rust or Corrosion on Pipes

Visible rust or corrosion on exposed pipes can signal a slow leak. Over time, moisture buildup weakens pipes, increasing the risk of leaks or bursts. If you see discoloration, flaking, or rust, have a professional inspect your plumbing system before it worsens.

If you think you might have a water leak, call us now before it gets worse!

How to Find the Source of a Water Leak

If you suspect a leak but aren’t sure where it’s coming from, follow these steps to find a water leak before it causes further damage:

1. Check the Water Meter:

• Turn off all water inside and outside your home.

• Watch the meter—if it continues running, you likely have a leak.

2. Inspect Common Leak Areas:

• Look under sinks, around toilets, and near appliances like the dishwasher and water heater.

• Check visible pipes for rust, corrosion, or moisture.

3. Listen and Look for Clues:

• Pay attention to dripping sounds, hissing, or running water behind walls.

• Look for wet spots, water stains, or mold growth.

4. Use the Food Coloring Test for Toilets:

• Add a few drops of food dye to the toilet tank.

• Wait 10–15 minutes—the toilet flapper is leaking if color appears in the bowl.

5. Check Outdoor Plumbing:

• Inspect hoses, irrigation systems, and outdoor spigots for pooling water.

• Look for unusually green or soggy patches in your yard.

Brothers can help with expert leak detection and repair services if you can’t locate the leak. You can give us a call at 704-620-6252 for fast, reliable assistance. 

Potential Problems with Undetected Leaks 

Ignoring signs of a water leak can lead to serious and costly damage to your home. Here’s what can happen if a leak goes unnoticed:

• Water Damage: Prolonged exposure weakens drywall, causes stains, and leads to wood rot. Excess moisture may also cause flooring to warp, bubble, or become soft.
• Structural Damage and Foundation Issues: Leaks can erode the foundation, causing cracks and shifts, and compromising the home’s stability.
• Mold and Mildew Growth: Persistent moisture creates the perfect environment for mold and mildew, which can trigger allergies, respiratory issues, and expensive remediation costs.
• Higher Water Bills and Wasted Resources: Even a slow drip can waste hundreds of gallons of water, increasing your bill and strain your plumbing system.

The longer a leak goes undetected, the more damage it can cause. Addressing signs of a water leak early can help you avoid major repairs and unnecessary expenses. 

When Is a Water Leak an Emergency?

Not all leaks require immediate action, but some situations demand urgent attention. Here’s when a water leak in your home becomes an emergency:

• A Major Visible Leak Causes Flooding: Large amounts of water can quickly damage floors, walls, and valuables. Shut off the main water supply and call a professional immediately.
• A Leak Near Electrical Systems: Water and electricity are a dangerous combination. If you see moisture near outlets, wiring, or your breaker box, turn off the power and seek help.
• Persistent Moisture Causes Mold Growth: If a leak allows mold to spread, it can pose serious health risks and should be addressed immediately.
• A Hidden Leak Causes Structural Damage: Leaks behind walls or under floors can weaken your home’s foundation and lead to expensive repairs if left unchecked.

If you’re facing any of these issues, don’t wait. Call us now at 704-620-6252 for emergency plumbing services! 

Preventing Water Leaks with Regular Maintenance

Routine maintenance, such as pipe and appliance inspection, is key to avoiding costly leaks. With Brothers' Pro Service Plan, we’ll conduct thorough inspections to catch problems before they start—helping protect your home and plumbing system year-round.

When to Call Your Local Brothers Experts 

If you suspect a water leak in your home, don’t wait to call. Brothers offers expert leak detection, plumbing repairs, fixture installations, and more, with specials to help you save. Serving homeowners across the North and South Carolina region, we’re here when you need us. 

Call 704-620-6252 today to schedule service!