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Roofing

How to Repair Roof Leaks

On this page:
  • Signs of a leaking roof
  • How to fix roof leaks

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How to Fix a Leaking Roof

A single roof leak in your home can cause irreparable damage if left unchecked. Knowing how to fix a leaking roof and how to regularly inspect for roof leaks can be incredibly beneficial in saving your home from extended damage. On this page, you will learn how to spot telltale signs of a leaking roof, and what to do to fix the problem after finding a roof leak.

Spotting Signs of a Leaky Roof

It is important that you know what to look for to identify a leaky roof. When you know the warning signs, you should have no trouble not determining that your roof is in fact leaking, and also pinpointing the general area of the leak. Below you will find the most common signs that you have a roof leak that needs to be fixed as soon as possible.

Water Stains

If you see any brown, gray or yellow stains on surfaces or ceilings in your home, these are typically caused by water damage. Look out for the stains on the walls and ceiling sections, and pay close attention to see if they worsen.

Inside a home with a roof leak.

If you spot a stain in one of these areas, you should immediately start looking for the cause of the leak in the area. The sooner you spot the reason the roof is leaking, the sooner it can be repaired. Water stains on the ceiling are common with leaking roofs, or leaks from the bathroom on the upper floor.

It is best that you call in the professionals to assess the damage and determine where the leak is coming from.

Curling, Broken, or Missing Roofing Shingles

If you see any shingles that are cracked or broken, curling up away from the roof, or missing, that is a problem. These are sections that can and will allow water into your home. Visually inspect the roof of your home regularly for these problems so you can resolve them before they lead to water getting into your home.

A roof with a shingle missing causes roof leaks

Home Mold Formation

If you notice mold forming on sections in your home near the roof, there is a good chance you are suffering from a minor roof leak. Major leaks are most often accompanied by larger water stains.

If there are no water stains, but clearly some mold in a section of the roof, moisture is getting through enough to keep things damp, but not enough to really cause staining. Look outside your home near the spot you saw the mold for obvious signs of a roof leak.

Roof Blisters or Wrinkles

On a flat roof, the most common sign of a leak is blistering or wrinkling. You will notice serious creases or curled and wrinkled sections on your roof. These are signs that water is getting in under some of the layers of the roofing and then heating up and expanding. The issue needs to be resolved quickly, or water will make it all the way through your roofing.

Damp or Musty Smell

Check your attic regularly to see if it is developing a moldy or damp smell. While this could simply mean that you don’t have enough ventilation in the space, it is also a sign of a leaking roof that is allowing moisture in. You will likely notice damp and spongy plywood around the site of a leak, and possibly water stains.

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6 Ways to Repair a Roof Leak

There are several common causes of roof leaks. It is important to learn these causes and understand how to fix them, so you can solve the issue quickly and ensure your roof is watertight moving forward. Below you will find 6 common causes of roof leaks and how to fix them.

Repairing missing roof shingles

One of the most common causes of roof leaks on an asphalt shingle roof are from shingles that blew off the roof. This could be because they were not secured properly during strong winds. Fortunately, replacing missing shingles is a simple process.

  • Tap down all the existing nails so that they are out of the way. Pull out the nails from all the shingles above the row of missing shingles, at least one shingle to the side of the section on either side.
  • Pull out the nails from two rows above the opening. With the nails removed, you can now slip the replacement shingles into place. Nail them down by lifting the next shingle row up, and nailing underneath the shingles below the tar strip.
  • Finish by replacing all the nails that you removed on the undamaged shingles. You should not have a roof leak through that section of your roof any longer.

Fixing metal roofing fasteners

On metal roofing, the major weak point of the roof is at each of the fasteners screwed in place to hold it down. Fasteners are added at the upper portion of the folds of the roof to keep them away from sections where water would flow and pool generally. However, they can still allow water in if they wear away or begin to come up and stop holding tight.

The best way to fix worn out roof fasteners is to replace them with a longer and more durable product, preferably one with a larger rubber washer. The fasteners with a larger washer provide more comprehensive protection and can fill in old screw holes if you have to fasten the panel in a spot that’s slight over from the original hole.

A roof with shingles starting to curl causing a leaky roof

Fixing lifting shingles

Your roof can begin leaking if the shingles are not adhering properly. The little tar strips on all the shingles are designed to serve as glue to hold the shingles together. If the shingles were installed in cold weather, they may not have ever adhered properly.

The simple fix to this problem is to apply a layer of roofing cement underneath the shingles where they seem to be lifting up. Do this on a warm day so the cement comes out easily. Be sure to press the shingles down into place after applying the cement. After a few days, you should see that the shingles are no longer lifting up like they were.

Fixing a roof leak around a drain or vent

Drains and vents are typically sealed using a rubber boot on your roof. Rubber does not last forever. Most of the time, when you notice a roof leak beginning to develop in this area of your home, you simply have to replace that rubber boot.

To do this, inspect the boot for signs of a tear or cracking. If there is an obvious problem, purchase a new boot designed to fit the diameter of the pipe or vent. Lift up the roofing around the boot, and pull out all the nails holding the flashing in place. Slip the boot up and out of the way and slip the new one down.

Be careful to slip the flashing surrounding the boot back into place properly, or new leaks will occur. The flashing should be under the roofing around its sides, and on top of the roofing at its bottom to let water flow freely.

This application only works properly on shingle roofing, and you’ll have to secure the boot in a different manner on panel roofing. Instead of putting the flashing underneath the roofing, you simply lay it down flat against the roofing and seal underneath it heavily using roofing caulk. After it is sealed, screw it in place with screws that have rubber gaskets to keep water out.

This installation method is not quite as durable and will need retouching more often. However, it is necessary with larger sections of roofing.

Fixing a roof leak around a skylight

Leaking around a skylight, especially an older one, is very common. To fix the roof leak, you typically have to remove all the waterproofing and the layer of shingles over top of the edges of the skylight windows so that you can waterproof it properly.

Cut off the shingles, the flashing, and anything else that is covering up the skylight and the area 6″ around the skylight. With the section cleared all the way down to the OSB decking, it is time to get started waterproofing your skylight.

  • Install an ice and water barrier up to the nailing flange of the skylight along the bottom, with the barrier going underneath the row of shingles just below, but over the next row of shingles down. This will allow water to run down the ice and water shield and back over top of the shingles once again.
  • Install the barrier along the sides. Make sure that it runs under the shingles and over top of the bottom row of the barrier.
  • Finally, run the top row of the barrier up to the flange so that it covers the sides and runs underneath the row of shingles up above. This creates an effective water barrier for the skylight.

To make the skylight even more water resistant, install step flashing along the side edges of the skylight in between the rows of the new shingles that you install. Top the skylight with a wide piece of metal flashing that comes out over top of the nailing flange and the ice and water barrier. Top that with new shingles to complete your waterproofing. Your skylight will no longer leak.

Fixing a chimney roof leak

Chimneys are a common problem area for a water roof leak. Common sections of a chimney that lead to roof leaks are the cricket and the counter flashing.

The cricket is a small peaked section on the chimney’s high side designed to divert water around it. The cricket should be sealed into the grout of the chimney itself firmly. If it has come off, reapply it using a waterproof roofing sealant.

There is also the counter flashing. This is installed at the sides and base of the chimney. It’s the vertical portion of the flashing designed to keep water from running down and underneath the chimney. Counter flashing should also be sealed right into the mortar of the chimney. You can use roofing sealant or mortar to lock the flashing back in place if it slipped off.

Hiring a Roofing Professional

Roof leaks are serious problems that can lead to very costly water and structural damage in your home. If you suspect your roof is leaking, your best bet is to talk to a professional roofer. A qualified local roofing contractor will be able to visit your home, inspect the roof damage, and recommend a solution.