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7 Reasons Why Your Roof Leaks in Heavy Rain and the Cost to Fix Them

Written by Adam Graham

Published on March 6, 2023


7 Reasons Why Your Roof Leaks in Heavy Rain and the Cost to Fix Them

Does your roof leak in heavy rain? Check out these 7 possible reasons why and how much it costs to fix them.

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If you have noticed that your roof leaks, you need to address the issue as soon as possible. While you may think the problem is minor because it only leaks in heavy rain, your roof should always be completely watertight. 

There are a few common reasons you might have a roof leak and others you might not expect. While this article may help you figure out why you have a leak, it is essential that you hire a professional roof inspector to identify issues and be entirely sure your roof is in good health. Once you have identified the cause, fixing it as soon as possible is crucial to avoid the issue worsening. Below, we share how much it will cost to repair a roof leak, depending on the problem.

Here are 7 possible reasons why your roof leaks in heavy rain and the cost to fix them:

1. Chimney Leaks

If your home has a chimney, it is more likely to suffer leaks as they are a prevalent cause. One of the main reasons is the flashing around the chimney. Flashing is a metal sheet that covers the area where the chimney meets the roof. Water can seep in when the angle flashing is damaged or has come loose. It could also be because it wasn’t installed properly in the first place. 

After a big downpour, water is often retained in the material of the chimney itself, including mortar. If saturated, water could begin to seep through. Also, in heavy rain, water can sometimes enter directly through the chimney itself, which means there could be issues with the masonry chase top. 

Cost to fix a leaking chimney: $500 - $4,500

Hire a local roof contractor to fix a leak

2. Skylight Leaks

A skylight is designed to allow for more light to enter. While it is not intended to let rainwater leak through, it is sometimes the cause of leaks. Similar to flashing surrounding the chimney, this could be because it has not been installed properly. The skylight needs to be correctly insulated, ensuring there are no gaps around the frame or flashing. Poor insulation can lead to condensation, meaning water will drip inside. 

If your skylight is reaching the end of its lifespan, then you may find the seal has worn down. Another common reason for leaks through the skylight is that it hasn’t been closed properly. 

Cost to fix a leaking skylight: $500 - $750

3. Degraded or Damaged Shingles

Shingles may not be the cause of leaks whenever it rains, but when they begin to near the end of their lifespan, you may notice leaks starting to occur during heavy or prolonged rainfall and snowfall. This is because the shingles, which are designed to protect your home from the elements, have worn down and dried out. Shingles can also suffer damage, especially when there are storms, which is why you might notice a leak. 

Cost to fix damaged or missing shingles: $200 - $700

4. Clogged Gutters

Gutters are crucial in protecting your roof and home from water damage. Their purpose is to direct water away from the home so as not to seep through the roof or walls. If not properly and routinely cleaned, a build-up of leaves and debris can occur, which will stop the functioning of the gutters. Water can back up on the roof which, in heavy rain, causes leaks, especially in roof valleys. 

You should have your gutters cleaned at least twice a year to avoid this issue. The best times to have your gutters cleaned are around spring and fall. 

Cost to clean gutters: $200 - $400

5. Roof Vent Leaks

If your home has a vent that protrudes through the top of your roof, it could be one of the causes of roof leaks in heavy rain. It is possible that there is an issue with the vent cap, but the most common cause is usually the roof boot. The roof boot is the rubber seal around the base of the vent stopping water from entering the home. This rubber can dry and crack, which can then let water in. It is a relatively simple and affordable fix. 

Cost to repair roof vent: $250 - $400

6. Metal Roof Leaks

Depending on the material your roof is made from will determine which potential issues are causing leaks in heavy rain. If your roof is made from metal, then there is the possibility that the metal is corroding or cracked. It is essential that you keep your metal roof well-maintained to avoid this from happening. 

Cost to repair metal roof leak: $500 - $2,000

7. Roof Flashing Issues

As mentioned, flashing is used around the chimney and roof pipe vent but is also found in other important parts of the roof, sealing protrusions and edges. If cracked, rusted, or with holes in the metal, leaks can seep through. Make sure your roof is inspected regularly to ensure that the flashing, and the roof in general, is in good health. 

Cost to repair cracked or missing roof flashing: $300 - $1,000

Get in touch with a local roofing contractor

Author: Adam Graham is an industry analyst at Fixr.com. He analyzes and writes about the real estate and home construction industries, covering a range of associated topics. He has been featured in publications such as Better Homes and Gardens and The Boston Globe, and written for various outlets including the National Association of Realtors, and Insurance News Net Magazine.