How to Find a Roof Leak (2023)

By Amanda Lutz

Nov 24, 2023
Repairman in helmet holding a hammer while repairing a roof leak.

A leaky roof requires immediate action to prevent extensive damage to your home. Before you fix the leak, you need to find the source of the problem. This is no easy feat, especially on flat or low-pitch roofs.

Below, we offer step-by-step guidance on how to find a roof leak and the process of securing quick repairs. If you ignore a leak for too long, you could wind up paying thousands of dollars for mold remediation, total roof replacement, and water damage repair.

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The Importance of Finding and Repairing Leaks Quickly

A roof leaf can work its way down from the top of your roof down to your home’s foundation. Water leaks can cause significant damage to your roof and other areas of your home, leading to structural damage such as rot and decay.

The first place water will travel if there is a leak is into your attic and ceilings. Attics often contain important home systems, such as heating or air conditioning equipment, and exposure to water or moisture could lead to system failure or the makings of a fire hazard. Water can also make its way into your home’s insulation and drywall, causing mold and mildew growth, and can weaken rafters and ceiling joists. Even worse, it could damage your flooring, wall framing, paint and plaster on walls, furniture, and personal belongings.

Signs of a Roof Leak

Not every roof leak is immediately noticeable, but there are telltale signs to watch out for. Check your attic first for signs of damage. This is the area where roof leaks show the soonest. Look at the flooring and the bottom of the rafters for water stains. Walk through your home and look for water stains on the ceilings or mold growth on your home’s exterior walls. Listen for dripping sounds coming from the attic or elsewhere in your house.

Here are some other common signs of a roof leak:

Inspecting the Roof Exterior

Once you find signs of interior water damage from a leaking room, it’s time to inspect the roof from the outside. After it rains, use a ladder to get an eye-level view of the roof and look for signs of damage, such as missing or damaged shingles, flashing issues, or debris buildup. You can also use binoculars from the ground or a drone to get close-up photographs and video footage if you’re uncomfortable with heights.

Moss could be a sign of consistent moisture on your roof, which can lead to rot and deterioration. If you notice pooling water on a flat or low-pitch roof, look inside your home near the puddle’s location. A leak may not occur directly below, so search closely around the suspected area.

Inspecting the Roof Interior

Go into your attic and inspect every rafter for evidence of moisture, especially the bottoms of rafters and any points at which two planes meet. Examine the flooring for water stains, peeling paints, patches of mold growth, wet insulation or drywall, and other common signs.

Remember that not all signs of water damage in the attic are the product of roof leaks. Condensation, broken pipes, and AC leaks can cause foggy windows, high humidity, musty odors, and structural damage.

If you don’t have an attic, check your ceilings for water stains or parts of your ceilings or walls that have warped. Watch and listen for drops after it rains, as this could be a sign that water has penetrated the area.

Locating the Source of the Leak

Once you’ve found evidence of a leak, you’ll need to pinpoint the leak’s exact location. Only then can you set the repair process into motion. Go into the attic on a rainy day and look or listen for dripping water.

If you can’t locate the leak’s entry point in the attic, get onto your roof and use a flashlight to closely examine areas prone to leaks, such as skylights, valleys, and vents. You can also try removing shingles around the suspected area to inspect the roof deck, looking for discolored paper, water stains, and rotted wood.

Another option is the water spray test. Use a garden hose and start soaking around suspected areas one by one. Start on the lower section of your roof first and work your way up. Have another person inside the home listen for dripping. Spend several minutes at each location before moving to subsequent areas.

Finding Difficult-to-Locate Leaks

If you’re still unable to find the cause of the roof leak, enlist the help of tools such as infrared cameras, conductive moisture meters, smoke pencils, or professional leak detection services. These will help you to find hidden water and moisture problems without intrusive or destructive testing.

DIY Roof Leak Repairs

Homeowners can make minor roof leak DIY repairs, such as resealing roof flashing, applying sealant, patching shingles, and clearing debris from drains and gutters. If you see patches of moss, you can remove them while equipped with the necessary safety gear and cleaning solutions. Read our guide on how to remove moss from a roof for more details.

We don’t recommend making extensive repairs unless you have professional roofing experience. Roof work is dangerous, and if you don’t seal everything correctly, you could set yourself up for bigger and more expensive problems.

Fixing Leaks from Recent Storm Damage

Homeowners can perform temporary DIY repairs after major storms. Consider tarping damaged areas to prevent water penetration, clearing debris from gutters and drains, sealing vents, and patching small holes or tears. The first thing you should do is contact your homeowners insurance company to report any damage a storm has caused your roof.

If there’s leaking due to damage from a covered peril, such as windstorms, hail, snow, sleet, ice, lightning, fire, and falling objects, your insurance company may pay to repair or replace your roof up to the coverage limit, minus your deductible. If there’s a leak because of negligence or wear and tear, your insurance policy will probably not cover the repair cost.

Professional Roof Leak Repair

Professional services such as inspections, preventative measures, and roof leak repair will help keep your roofing system in working order.

Most homeowners spend between $125 and $350 on a roof inspection.* If the inspector spots potential problem areas, you can hire a roofing company to install preventative measures, such as drip edges, which costs $150 to $1,000 on average. The average roof repair cost is $150 to $2,000 to fix a leak.

If your roof experiences extensive damage or damages compound because they haven’t been addressed quickly enough, you may require a new roof. The average new roof cost ranges from $5,700 to $12,500.

*Cost data in this article was sourced from HomeAdvisor and Angi.

Preventing Future Roof Leaks

Homeowners can take proactive steps to prevent leaks, such as cleaning gutters, checking flashing, sealing joints, pruning overhanging trees, and getting regular inspections. 

The National Roofing Contractors Association recommends homeowners inspect their roof systems at least twice per year in the spring and fall and after severe weather. Check the flashing around leak-prone areas and seal joints if necessary. Cut back overhanging tree branches and keep your roof and gutters clear of branches, leaves, and other debris.

Our Recommendation

Homeowners with experience performing DIY home improvement projects can learn how to successfully locate roof leaks and start necessary repairs. If you feel uncomfortable doing the work on your own or if there’s extensive damage, we recommend hiring professional roofers to make necessary repairs.

Never ignore roof leaks, no matter how innocuous they may seem at first. Leaving an unresolved leak for too long can lead to additional structural damage to your home.

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How to Find a Roof Leak FAQ

What are the most common causes of roof leaks?

The primary cause of a leaking roof is the roof’s age. Other common causes of roof leaks are poor maintenance, clogged gutters and ice dams, damaged or missing shingles, damaged flashing and roof vents, and cracks around chimneys or skylights.

What areas of the roof are most prone to leaking?

The areas most prone to leaking are flashing, skylights, roof valleys, chimneys, vents, and other protrusions. If you suspect a roof leak, check around these areas first when making your exterior inspection.

How can I tell if the leak is coming from the roof or plumbing?

Roof leaks and plumbing issues can look similar and can both cause mold or mildew growth and damp spots on your walls and ceilings. A sign that you have a plumbing leak is an unexpectedly high water bill. If your water meter is running even when everything that uses water is turned off, you probably have a plumbing leak.

What is the best way to find the exact location of a leak?

It’s not always easy to find the exact location of a leak. Start by looking in the attic and your home’s interior before performing an exterior inspection. The best way to find the location of a leak is to look for signs of water damage, such as peeling paint or wallpaper, water stains on the ceiling or in the attic, and mold growth on your exterior walls.

How much does it typically cost to repair a roof leak?

The average cost to fix a leaking roof is between $150 and $2,000. Some homeowners can make minor repairs for less, but extensive damage can cost significantly more and require the help of a professional roofing company.