Home Articles

Roof Leak Repair: How to Find and How to Fix Step-By-Step

Jack Wisniewski

Published on February 23, 2021


Roof Leak Repair: How to Find and How to Fix Step-By-Step

Prompt roof leak repairs can save you hundreds, if not thousands of dollars in water damage. Learn what to do step-by-step when a leak springs up.

To provide you with the most accurate and up-to-date information, we consult a number of sources when producing each article, including licensed contractors and industry experts.

Read about our editorial process here. Want to use our cost data? Click here.

So you just noticed water stains on your walls, a bulge in your ceiling, or a puddle on the floor leading towards a roof leak.

Not ideal, but also not the end of the world.

Assuming you act quickly, fixing a leak can save you hundreds upon thousands of dollars in roof repair costs. The fact that you sought out this article means you are well on your way to restoring your leaky roof and preventing any further water damage!

To get you started, we'll provide you with a couple of methods to help you spot the problem area. With the leak source identified, you can then implement a quick fix to avoid more damage before making permanent repairs.

Those seeking to save money with DIY roof repairs can find one simple method to restore their leaking roof to its former impenetrable glory.

Homeowners looking to gauge quotes from roofing contractors straight away can skip to our section on typical roof leak repair costs.

How can I tell where my roof is leaking?

Image source: Whitehall Carpet Cleaners

You can't fix the leak until you know where it's coming from.

Although leaks usually spring up near penetrations and fixtures, like skylights, roof vents, and chimneys, they can strike anywhere.

Determining the exact location of the leak is usually the most difficult part of the process. Even though you can easily spot stains and mold from the inside, the water could have worked its way there from a distant point in your roof.

Find local pros to inspect your roof for leaks today

Image source: Lundberg Specialty Services

If you have an attic, the most straightforward way to identify the leaking portion of your roof is to venture up there with a flashlight and seek it out.

Watch your step. Many attics don't have solid flooring, which means you will need to walk on the joists. Stepping between joists could send you through the ceiling and into the room below.

Up in your attic, inspect the underside of your roof and pay attention to dark spots, water stains, and mold. These tell-tale signs should point towards the origin of the leak!

Leak detection method no. 2: recruit a helper and get the garden hose

Image source: DIY Network

If you don't have an attic, or couldn't zero in on the trouble area during your visual inspection, you and a trusty helper can simulate rainfall on your roof to detect where water gets through.

One person should head up to the roof with a garden hose while the other stands in the house where they can see directly beneath the roof, ideally the attic.

Starting towards the eave (bottom), hose one section of the roof and slowly work up. This approach aims to demonstrate how your roof handles a true rainstorm, so you should douse each area of the roof for several minutes to let water make its way through the leak.

The person in the house should eventually notice water seeping through and alert you to stop hosing. At this point, you've passed over the leaky part of your roof!

If you plan on making a home insurance claim, now is a good opportunity to snap photos for evidence.

What to do if your roof is leaking

The answer to that is obviously to fix it permanently, but that might not be possible at the moment, whether the rain is still coming down or you can’t get a professional team out in the aftermath of the storm.

Unless you can hire a 24-hour roofing company or plan to make your own lasting repairs right away, a temporary fix will prevent any further damage to your home.

Contain the leak

Image source: O’Neill and Brown Plumbing

First, contain actively leaking water. If possible, move any belongings out of the way and place a bucket or garbage can down to capture the water.

You may notice your ceiling sagging around the leak. To slowly drain the water, puncture the bulge with a screwdriver. It might seem counterproductive, but relieving the pressure will prevent your ceiling from collapsing under the weight.

Cover the leak

As far as stopping more water from entering your home, we outline two ways to go about it.

The first approach entails a tarp and is suited for covering large areas over pitched shingle roofs. The second involves sealing small leaks around roof penetrations or on flat roofs.

A note on safety: do not walk on a pitched roof during a storm. Roofs are slippery when wet. Either perform these fixes after your roof dries or stay on a ladder.

How to tarp your roof

Image source: Preman Roofing Solar

Required tools and materials:

  • Tarp
  • Six two-by-fours
  • Hammer
  • Cap nails
  • Screws
  • Screw gun


  • A partner

Before getting out these materials, measure the dimensions of the leaking area. The tarp will need to stretch over the entire area as well as overhang the ridge and eave of your roof by at least four feet. You should have enough two-by-fours to line the perimeter of the tarp.

With all of the materials ready:

  • Remove any debris and loose shingles from the area so the tarp can sit flush along the roof.
  • Starting behind the ridge, unroll the tarp all the way down to the opposite eave to cover the damaged area. The tarp should hang over the eave by at least four feet.
  • Nail the top-end of the tarp to a two-by-four parallel to the eaves.
  • With a few rotations, wrap the nailed-down tarp with the two-by-four.
  • Screw the two-by-four to the roof to anchor it down.
  • Nail the opposite edge of the tarp to a two-by-four.
  • Off your roof, roll that end of the tarp a few times like step four. Make it taught enough so the tarp won't flutter in the wind.
  • Screw the two-by-four to the wall beneath the eave.
  • Reinforce the tarp by screwing two-by-fours along the edges.

Voila – a temporary roof covering!

Note that screwing the boards into your roof will create more holes in your shingles and underlayment, which can lead to more leaks. Try to keep screws to a minimum and prepare to have those shingles replaced when making your permanent repairs.

How to seal a roof leak

Image source: Roofer 911

Required tools and materials:

  • Roofing cement/sealant/caulk
  • Trowel

For small leaks or leaks around a roof fixture, using roof cement or sealant might be your best bet. Bear in mind that you must use sealants above the leak. Using it on the inside will only divert the water elsewhere beneath your roof deck.

  • Apply caulking beneath the shingles or on top of the damaged area.
  • Overlap the coating of sealant with surrounding shingles.
  • Recoat for extra protection.

How to fix the leak in your roof

To put the leak to bed, you'll need a permanent fix. Fortunately, replacing damaged or missing shingles only requires a few tools and materials. We outline the steps to perform a shingle replacement below.

However, if fixing your leak entails addressing structural roof damage, complex fixtures like dormers, or flashing systems, repairs should best be left to a professional.

Now would be the perfect time to check whether you have an ongoing roof warranty – this could help save you the cost of replacing materials and paying for labor.

How to replace roofing shingles

Image source: IKO

Required tools and materials:

  • Pry bar
  • Replacement shingles
  • Hammer
  • Roofing nails
  • Roofing cement/sealant/caulk

How to replace shingles step-by-step:

  • Gently, lift shingles surrounding the missing/damaged shingle with a pry bar to break their seal. Pulling too fast or too high can tear the shingle.
  • Pull out the nails of the missing/damaged shingle, including those set through the course above.
  • Now that it's loose, remove the damaged shingle.
  • Slide the new shingle into position making sure it fits exactly like the old one.
  • Nail the new shingle and renail the overlying shingles.
  • Reseal the shingles by placing beads of roof cement on their corners and pressing them into the deck.

Roof leak repairs: the bottom line

Get your roof leak fixed as soon as possible. It may seem insignificant now, but the damage will only worsen over time.

Stemming the flow and making prompt repairs maximize the value of your roof and save you from the hefty costs of getting a full roof replacement.

If you can't repair the leak yourself, consider hiring a vetted, local professional with the help of Fixr.com.

Get free estimates from trusted roofing companies

Written by

Jack Wisniewski Author

Jack Wisniewski is a writer and researcher at Fixr.com. When he is not guiding readers toward their optimal home improvement decisions, you can find him working out or watching professional soccer.