How to Repair a Leaky Roof

Every roof has a limited lifespan. After many years, shingles can blow away and roof sealants and roof coatings can begin to break down and leak. If your roof is past its prime, visit the Lowe’s Roofing Installation page to have one installed by a trusted contractor.

Roofing requires some occasional upkeep such as cleaning your gutters, replacing missing shingles and removing heavy snow and ice buildup. Failing to perform regular maintenance can cause damage to your roof, which can lead to leaks.

Roof flashing is sealed with tar or another type of sealant to keep water from penetrating the structure. Over time, seals can break down, resulting in a leak. Severe weather or strong winds can also cause the flashing to warp or crack.

A roof valley is a portion of a roof where two slopes connect. Pooling rainwater and accumulated ice can compromise the sealant in valleys over time.

Roof boots are a special type of flashing used to seal around pipe vents that exit onto your roof. If this flashing is missing or damaged, it can allow water to seep down into your attic, creating wet spots in your ceilings or on walls.

Your chimney is built of masonry materials and mortar that can corrode and crack over time just like other roofing components, which is why it’s important to perform regular chimney inspections.

Skylights that aren’t installed correctly or that were installed many years ago and may have leaky seals are another common source of roof leaks. This type of problem is usually easy to diagnose as you’ll simply notice water dripping into your home around skylights.

Gutters perform an important function around your home, namely channeling water off your roof and away from your home’s foundation. However, if your gutters are clogged, this can cause water to pool on your rooftop and soak in over time.

Inclement weather such as storms and high winds can cause missing shingles and fragile tree limps to fall on your roof, leading to holes or warping of the roof’s structure. Also, as winter snow collects in roof joints and melts and refreezes over time, it can form what are known as ice dams. The extra weight created by the ice can weaken roofs, plus ice dams prevent melt water from rolling off roof shingles, causing it to back up under the shingles and creating the potential for leaks.

Even if rainwater isn’t penetrating your roof, moisture can accumulate in your attic due to condensation from extreme temperature differences and drip down into your ceilings. If this occurs, you may notice large, stained portions of your ceiling, moldy spots or a musty smell lingering in your home.

Inspect around ceilings and walls in your home to see if you notice any stains, discolored spots or visible drips. Next, enter your attic with a flashlight to see if you can easily see the source of the roof leak. If you can’t, grab a garden hose and enlist a couple of helpers.

Use a tall ladder to safely go up on your roof and spray water over the area you suspect may be leaking while one of your helpers watches for leaks in the attic. Have your other helper nearby to steady the ladder and assist with the garden hose. This technique will give you a general idea of what area(s) of the roof you’ll need to focus on. Follow the remaining steps for additional tips and solutions.

Step flashing components are thin, L-shaped metal pieces that cover roofing joints and spaces around chimneys and dormer windows to keep water out. These metal pieces are typically covered with a rubberized coating which can break down over time. Any loose or exposed flashing will need to be secured with roofing cement and resealed.

Locate any roof vents and vent boots on your roof and check the flashing and seals around these structures. Look for any missing components, weak or broken seams, cracked or decaying rubber gaskets around vent pipes or missing nails or screws. Replace anything that requires it and reseal as needed. If the roof vents or vent pipes themselves are damaged, they will need to be replaced as well.

Mounting holes left over from satellite dish brackets, old vents or anything else that may have may been installed on your roof in the past can create a prime location for water to seep through. Inspect any previous mounting areas and seal off any holes left by screws or nails using a commercial sealant or by covering the area with a piece of roof flashing.

Falling tree branches due to inclement weather is a major cause of roof damage. While small cracks can be treated with a rubberized wet patch, holes and other serious damage will require the services of a professional. Once the issue has been mitigated, it’s important to guard against future damage. If you have trees close to your home, prune nearby branches —especially ones that are old and diseased — to prevent them from falling onto the roof in the future. If the entire tree is diseased or unstable, you’ll want to have it removed by a professional.

Functional, free-flowing gutters will allow water from rain and snow and ice melt to properly drain away from your roof, preventing water damage. To keep your gutter drains clear, you’ll need to clean them regularly. To learn more about how to keep your gutters in top shape, including how and when to clear away debris, see How to Clean and Repair Gutters.

It’s important to keep your chimney in good working order both to prevent it from smoking up your house and to protect your home from fires. Regularly cleaning and inspecting your chimney, or hiring a professional to do the job, is paramount. Plus, a clean chimney is much easier to inspect for cracks and damage that could cause leaks in your home. For more information on proper chimney maintenance, including help on whether it’s best to complete the task yourself or hire pro help, see How to Clean a Chimney: DIY or Call a Professional?

Drastic differences between the air temperature in your home and in your attic can cause excess humidity and lead to heavy condensation. Water droplets can then form on ceilings and drip down into walls and insulation, leading to mold. If you notice this problem, talk to a professional about moisture remediation solutions for your attic.

Common Causes of Roof Leaks:

• Roof age and deteriorated shingles or sealants
• Lack of maintenance (clogged gutters, ice or snow buildup)
• Cracked or exposed flashing
• Poorly sealed roof valleys
• Damaged vent booting, chimneys or skylights
• Storm damage, ice dams or falling branches
• Excess attic humidity or condensation

Steps to Fix Roof Leaks

• Locate leaks using attic inspection and garden hose test
• Check dormer windows and skylights for worn caulking or flashing issues
• Inspect and reseal step flashing around chimneys and joints
• Examine roof vents and vent boot and repair or replace damaged parts
• Seal old mounting holes from past installations
• Trim or remove nearby trees to prevent branch damage
• Clean gutters to maintain water flow
• Inspect and maintain chimneys regularly
• Address attic moisture problems to prevent mold

Safety and Prevention Tips

• Mold from leaks can be hazardous — consult professionals if detected
• Use proper ladders and safety practices when working on roofs
• Regular inspection and maintenance are key to preventing costly damage

It’s easy to take on a simple roof repair yourself with step-by-step instructions and the right tools and materials from Lowe’s. Here are some of the most popular roofing categories our customers depend on.