Repairing A Roof Leak [DIY Guide]

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​As a roofing contractor in Phoenix, Arizona we’ve completed our share of roof repair projects. Since we don’t experience rain year-round, when storms hit, homeowners are left scrambling trying to find an available professional to repair a leak.  During these times, here at the office, we are flooded with calls from homes and businesses alike – the more rain we get, the more the phone rings off the hook. While this is good for us, it’s frustrating for homeowners who are in need of a quick repair.

Here’s everything you need to know about roof leaks and DIY step-by-step repair methods.

Table of Contents

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4 Common Causes of a Leaking Roof

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Leaking roofs can be attributed to any number of different causes. We’ll cover all the most common reasons roofs leak.  While some repairs are best left to the professionals, many of these repairs can be completed with a basic level of handymanness.

1. Cracked Flashings:

Flashing are the thin pieces and strips of metal that are installed under your roof shingles. They serve as a barrier between the shingles and the roof itself, generally around seams and joints on the roof, and keep water from slipping between the cracks. They sometimes have rubber overcoatings, as well.

Flashings crack because the tar and rubber used to seal them gets worn down over time, due to exposure to the elements like rain and sun, as well as just due to age and drying out over time.

2. Broken Shingles:

asphalt shinglesThis is one of the most common causes of roof leaks. Shingles – especially asphalt shingles – will wear down, crack, curl and break over time…leaving parts of the roof exposed. While underlayment and flashing will help, cracked, broken or even missing shingles will eventually lead to leak – no matter what.

Sun, rain, wind, snow, hail and heat all causes asphalt shingles to break, crack or curl over time. You’ll be able to see broken shingles when they look like missing patches of roof.

3. Improperly Installed Vents or Skylights:

poorly installed skylightSkylights, vents and other unique parts of the roof must be carefully and properly installed, or leaks will spring up around the seams. Proper installation of windows and vents usually means plenty of flashing and rubber overcoating around all seams and edges. When these leaks do occur, however, they are usually pretty easy to spot; you’ll notice water dripping around your skylights or parts of the ceiling or attic directly underneath vents.

4. Problems with Your Valleys:

Valleys – the V-shaped region where two sloped parts of the roof meet – are common places for leaks and other problems to occur. Water sometimes builds up in these regions, as does debris. Over time, this can wear the shingles down or even damage them, and water can begin to seep through any cracks or breaks in the flashing or underlayment.

How to Repair a Roof Leak

It’s important to fix a leaking roof as soon as possible — for the obvious reason (water destroying your home)— water will breakdown the integrity of your roofs rafters, joists, and even framing of your home’s architecture.

guy catching water in a bucket

Buckets do not fix roof leaks . I know it sounds funny, but in locations like California homeowners try to get away with this method for a summer or two. It may only rain hard enough once or twice a year to actually cause a leak…and sticking a bucket underneath the leak is obviously the easiest “fix.”

Some of the more basic roof repairs can easily be done on your own, provided you’re familiar and comfortable with some DIY tasks and a bit of elbow for help

Locating the Leak

You should have a general idea of where the roof is leaking based on where the water is seeping through the ceiling. But once you get on the roof, look for cracked, broken or -out-of-place shingles. Don’t just look at the shingles that cover your roof. Look at the sections where they connect at, including- roof vents, dormers, skylights, chimneys, and corner overhangs.

You may even need to spray the roof down with your hose to pinpoint exactly where the problem is.

In Phoenix, many of our homes provide access into the home’s attic. Inspecting the attic is the easy way to assess the extent of the damage to the homes’ interior.

Repairing Shiners

nail penetrating roof     

Shiners are nails that missed the framing member and are popular spots for moisture and condensation to collect in a cold, damp attic. The water can then drip off onto your ceiling and drip right through. Here’s what to do:

  1.  Have a decent end-cutting nipper that is meant for snipping-off piano wire. Roofing nails are galvanized steel and are pretty tough. They’ll frost-over but if they start to rust, that’s a problem.
  2. Place the very end of the nipper as far against the protruding nail coming out of the wood beam. Snip it off as cleanly as possible without leaving much that is sticking out. If you can use an angle grinder to sand off the excess nail sticking-out is helpful. Use a handheld Dremel tool if space is restricted but watch out for sparks and use safety eye protection.
  3. Use a universal silicone adhesive. It needs to say silicone glue and not silicone caulking. There is a big difference. A brand such as Shin-Etsu’ is a good brand that comes from Japan but there are cheaper brands at your local Home Depot. Use a generous gumball-sized amount squeezed over the nail. Then smooth it out using a popsicle or coffee stir stick.

Replacing Leaking Asphalt Shingles

If missing or cracked shingles are the cause of your problems, you’re in luck. Replacing shingles by yourself is actually pretty easy. Just find shingles that match your roof in color, size and style, and replace the shingles in the area around your leak.

If the shingles were laid more than 10-20 years ago, chances are it might have wear-n-tear issues. Take a look at areas where there is a joint or dormer that asphalt shingles are placed. Where these are placed, they might have dried-up or cracked along the edges. Pay special attention to sections that butt-up against overhanging dormers and window frame outcrops.

If there is water damage that’s noticed by lightly lifting the leading edge with a paint scraper, then it needs attention.

lifting shingle to check for water damage

  1. See if there’s room to slide in some 45 degree angled shims alongside the dormer. You’ll need to have tin snips to make these ‘L-shaped’ pieces fit better. Then they can slide under the existing roof shingle and edge of the dormer. If nails are in the way, you’ll need to remove these shingles that run along that dormer edge.


  1. Place the shims that are laid in a pattern starting at the bottom edges first. Each shim will overlap the next and allow water to flow over these corners instead of draining into them. Use shingle nails to attach the shims in place 1-inch from the edges of their top corners. Use silicone glue to seal off open edges where moisture or ice might settle.


  1. Replace the shingles starting at the bottom and working upward. The last pieces put into place are the trickiest since these will need to slide under the existing shingles that are above the repair area. You might need to use silicone adhesive to keep these final pieces in place since these cannot be nailed.

To get more on information on replacing shingles see our full article on this by clicking here.

Vent Boot Leak Repairs

Some rooftops have vents that are built-in for kitchen ventilation. These vent boots are made to cover pipes with a metal covering, while others are just for venting air hot from your attic. The pipe version has a rubber gasket that slips over the pipe. These tend to rot faster and can leak as a result.  You’ll probably need to buy a new rubber boot, and then work the shingles around the old vent free (very carefully). From there, you can pry the old vent boot off and place the new one in (putting new shingles down or carefully putting the old shingles back) and seal it tight.

  1. Remove the old rubber gasket and inspect the metal plate that goes around the pipe. If the metal plate is not damaged proceed with fixing the pipe gasket. Replace or repair a plate if it’s rusting and attach new screws using stainless steel screws with rubber washers. These washers act as a gasket and keep metal against metal rust issues limited.


  1. The rubber pipe gasket needs to slide into place and should be snug but not overly tight-fitting. A great way to slide this over the pipe easier is using 1 part dishwashing soap to 5 parts water. This 1:5 mixing ratio wipes up with a washcloth or rag and leaves very little soap behind.


  1. Use more of the silicone adhesive around the lower bottom edge of the gasket to seal it better on the metal roof plate. Using a bit of silicone adhesive over the entire rubber gasket surface on the outside will help preserve the rubber for longer periods. You can use your finger to smooth it out and seal off the exposed edges. If you can find a UV protected silicone, this is even better. An excellent choice is Loctite 5910 gasket sealant.

Skylight Leak Repair

The edges of a skylight are always problematic since the best weatherproof caulking will eventually crack from the sun.

  1. Remove any cracked caulking and inspect all the edges for water damage. Use new silicone adhesive inside any gaps that are alongside the skylight that is obvious. There may also be enough room to attach angled shims that can be placed along the edges of a skylight frame. Use tin snips to carefully snip away sections that fit under the skylight edge. The rest of the shim should slide underneath existing shingles. These will need to be held in place with silicone adhesive of the skylight is made from metal. lifting shingles near skylight areaSmall screws can also be used along the skylight edge if the frame is wooden or plastic. Metal frames are harder to drill, but caution is used here since these screw holes may get in the way if it’s designed to open.
  2. Be sure to use weatherproof caulking or silicone adhesive along the upper edges where shims attach to a skylight.

Repairing Damage from Antenna Mounts

Many people have satellite TV dishes on their roof. It’s not the job of the guy who changes your satellite dish to plug-up holes left-over from a previous installation. And, if they do, it’s plugged with cheap household caulking that cracks and rots in the sun. This can lead to leaks that will cause problems later.repairing hole in roof

  1. Look at how many anchor bolts were used and remove any blocked holes that have been filled with caulking or filler material that is old or cracking. If these are the source of a roof leak, these need to be sealed-off correctly. It’s important to catch and repair leak problems like this before they damage your interior ceiling.


  1. Using flat roofing shims, the areas where anchor bolts can be covered should have these shims slid under existing shingles. Use silicone adhesive under the leading edge of a shim that slides over an anchor (or many anchors) holes. Make sure that the bottom of your shim hides underneath a shingle flap. This is so it cannot be seen so add some extra adhesive under edges where the bottom of the shim is placed. Press it down firmly so these shims are sealed in.

Fixing Flashing or Underlayment

Oftentimes, your shingles are totally fine…it’s the flashing or underlayment underneath the shingles that’s causing problems and needs to be repaired. This is a bit more labor intensive than just replacing some shingles, as you’ll need to remove ALL the old shingles, put in the new underlayment, and then put the shingles back.

Any time you reroof or partially reroof, you should replace the flashing in areas around the chimney, skylights or other vents.

Final DIY Roof Leak Repair Tips

  • You can flatten out curled asphalt shingles and then stick them back on the roof using caulk or roofing glue. It’s a good idea to gently heat up and soften shingles using a heat gun before handling them…to avoid breaking them.
  • Be sure to fill any joints around your flashing with roof cement…to make sure they are completely filled and sealed and won’t let any moisture drip in.
  • If any seam on the roof appears to be cracked or worn, go ahead and apply an extra layer of roofing cement or putty and prevent problems from popping up further down the road.
  • Be Safe. A wet roof is a dangerous roof. Don’t climb onto your roof if it is wet…and always wear rubber-soled shoes to give yourself maximum traction and stay as safe as possible when up on the roof.

When to Call The Roof Repair Pros

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While the handier and DIY-experienced among us are certainly able to tackle some of those DIY roof repairs above…there are times when you need to call in the pros.

Anytime you’re not comfortable with the repairs that need to be done, or the project requires lots of flashing, sealing and underlayment around vents and skylights, you’ll probably want to call in the pros.

Likewise, if your roof uses metal or ceramic tiles or shingles, repairing and replacing them likely isn’t something you can do on your own. You’re better off leaving serious repairs like those to the experienced pros who have the know-how and equipment to handle those tasks.

If you do decide to call in the pros, remember: the worst time to have your roof repaired is right after a big storm. This is for a couple reasons.

First, you might find that every single roofing company is slammed with repairs and hard to pin down to come do work for you. Good roofing companies may need to schedule your project out upwards of a month or two.

Second…right after a big rainstorm might be a little too late. By then, the damage may already be done – and a small leak may have turned into a much bigger problem. If you start to see small leaks pop up, you want to get them fixed as soon as possible…before monsoon season comes and a single big rainstorm turns those small leaks into big, wet problems.

As an additional note…If you schedule your roof repair BEFORE monsoon season, you not only get your choice of legitimate roofing companies and competitive pricing, but it’s more likely that the owner of the company will be supervising your project.

That can make a big difference when you’re undergoing an entire re-roofing project. You are making a large investment in that new roof….and you want the job to be done right. A good roof can last upwards of 20-30 years…while one cheaply done may only make it 5-10 years.

How to get the best service for your next repair or re-roofing project

To obtain the best service, it is always wise to schedule your repairs or roofing projects before the monsoon season, or before storms are upon us. You get your choice of legitimate roofing companies, they are willing to provide good customer service, and best of all, you will get a competitive price. During slower times contractors are willing to give fast and free bids; giving your the luxury of comparing deliverables vs. cost.

Moreover, when roofing companies are slow, it is likely that the owner of the company (or someone higher-up) will be supervising your project. This makes a big difference, especially when you’re undergoing a re-roofing project: You are paying a good amount of money for your new roof, you want the job to be done right. A roof that lasts for 20 years, like it should, is much different than a roof that begins showing problems after 5 – 10 years.

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Juan del Leon is the owner of Estrella Roofing Company in Phoenix, Arizona. He has severed Arizona since 1997 with repair and installation services. Throughout the years he has gained knowledge of of the industry and utilizes his website as a place to blog about his experiences and share his expertise.

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