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How Much Does It Cost to Repair a Roof Leak?

July 28th, 2020 | 8 min. read

How Much Does It Cost to Repair a Roof Leak?

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A roof leak is a stressful situation. You have to worry about the damage it's causing to your home and how to get it taken care of as quickly as possible. 

But you're biggest concern is probably how much it's going to cost you. 

Here at Bill Ragan Roofing, we answer tough questions other roofing companies don't want to. That's why we're going to give you an idea of much you'll have to pay to repair your roof. 

The prices below are rough estimates to give you a general idea of how much it’ll cost to repair your roof. The cost of roof repairs is ultimately based on your contractor’s overhead, roof complexity, roof accessibility, roof pitch, and more.

Let's get to the 6 most common causes of roof leaks, what the repair entails, and a ballpark estimate for the cost. And at the very end, grab the checklist of Questions to Ask a Roofing Contractor to help you find a great roofer to repair your roof leak.  

Improperly driven nails 

If a nail isn’t driven in far enough or driven in sideways, it will cause the head of the nail to work its way back up through the shingle. When it rains, water catches the head as it comes down your roof and follows the nail right inside.

roof leak from improperly driven nail

How is the roof leak repaired? 

To repair this leak, the roofer will have to break the seal on the shingle, lift the shingle up, pull the nail out, and move it. 

If the nail wasn’t driven in straight, they’ll have to pull the nail out, drive it in properly, and then lay some ice and water shield on top of it. If the nail worked its way through the shingle, then they’ll reseal the shingle as well. 

If the decking nail didn’t hit wood, then it's just a matter of moving the nail over to catch the rafter. Then they’ll fill the nail hole with some type of cement and reseal the shingle back down.

How much does it cost to repair the roof leak? 

This is one of the repairs that fall under the minimum service charge category. As long as there are not many backed out nails (5-10), you can expect to pay around $325 to repair this leak. 

Pipe boot failure

A boot is a type of roof flashing that goes around the base of the pipes coming out of your roof and waterproofs them. There are different kinds of boots a roofer could use, such as lead, plastic, copper, etc. 

The most common boot I see fail most frequently is a synthetic rubber neoprene pipe boot. Once it cracks over time from UV light, water will run down into a closet, kitchen, bathroom, or wherever you have the pipe coming out of your roof.

roof leak from cracked pipe boot

How is the roof leak repaired? 

The simplest way to repair this leak is to install a little rubber collar over the top of the old cracked neoprene pipe boot. The collar will encase the existing flange (the flat rectangular flashing that's around the bottom of the pipe) and last you another 10-15 years.   

How much does it cost to repair the roof leak?

Depending on the house and type of roof you have, it could be done for a minimum service charge, around $325. If your roof is steep and hard to access, it could be up to $400 or more to repair this leak.  

Debris in gutters that stop above a roof-line under a valley

A valley is where two roof slopes meet in a V-shape that allows water to flow down a roof freely. When a valley stops in the middle of a roof, it will have a gutter that runs into it so the water can continue flowing down. 

debris roof leak from debris in gutter that goes into a roof valley

The problem is with the fascia, which is the board that runs along the lower edge of the roof that carries all the gutters. When there’s improperly installed flashing or no flashing at all applied to the fascia board, a leak will happen. 

How is the roof leak repaired? 

To repair this leak, your roofing contractor has to pop the gutter loose and install 3 pieces of flashing. The flashing is brought behind the gutter, onto the roof, and then the last piece is tucked under the valley. 

How much does it cost to repair the roof leak?

To repair this leak you can expect to pay around $500 per gutter that goes into a roof valley. Be aware, if your roof has one gutter in the middle of a roof valley, then it’s most likely going to have more. 

Collar failure around a gas vent

Gas vents are incredibly important because they make sure any carbon monoxide coming from gas appliances vents out through the roof. 

Most of the time, these vents are installed by HVAC workers who slide a collar over an unsealed pipe and flange thinking it will shed the rain right off of it. Under normal circumstances, this works.

roof leak from collar failure around a gas vent

However, with a torrential downpour, water can splash under the collar and lead to water running down the pipe.

How is the roof leak repaired? 

To repair this leak, your roofing contractor will have to raise the collar up very carefully, seal it with a dark color caulk, and then slide the metal collar back down into the sealer.

Because of the importance of these pipes, roofers have to be very careful when trying to repair this leak so that carbon monoxide doesn’t go inside the house.

How much does it cost to repair the roof leak?

Depending on how steep and hard to access the roof is, this repair will start around $400 per gas vent. Because of how careful your contractor has to be when fixing this leak, the more time it takes, the more the price rises. 

Chimney wear and tear 

There are several ways a chimney can leak. It could be the metal flashing that goes under the shingles surrounding the chimney.

If it’s brick, it could be the mortar joints. It can also be water coming down through the top of the chimney. 

roof leak from water in mortar joints on a chimney

If it’s the chimney siding, water can get in the corners where the siding butts into the corner boards. Not only can those boards rot out, but so can the boards behind the chimney that you can’t see.

roof leak from chimney siding damage

How is the roof leak repaired? 

If the leak is from the flashing around the chimney, a roofer will just go in and reflash the area around it. If it’s from the mortar joints, they’ll have to apply a masonry water repellent to seal it. 

To repair the leaks in chimney siding, you'll need to hire a competent carpenter or siding man. For the chase top of the chimney, you’ll need to hire a licensed chimney sweep company for repairs because most roofers won’t have the proper licenses and, more importantly, the insurance to perform this kind of work on a chimney. 

How much does it cost to repair the roof leak?

No two chimneys are the same. The bigger the chimney, the more these repairs will cost. Reflashing around the chimney starts around $500. 

Sealing the mortar joints with a high-quality masonry water repellent starts at $500 and could go up to $2,500. To repair rotten siding, the price can be anywhere from $500-$4,000.  

If you do hire a roofing contractor that has the license and right insurance to replace a chase top, you can expect to pay around $500. Remember, I recommend hiring a licensed chimney sweep to handle this kind of repair. 

Improperly installed skylight

Skylights have gotten a bad rap over the years. Everybody thinks they all leak. However, for example, a VELUX skylight comes with a 10-year no-leak guarantee and could possibly have no problems for up to 25 years. 

Sometimes it’s a component or piece of the skylight, but the main cause of a leaking skylight is an installer not reading and following the manufacturer’s installation instructions. 

If you don’t have a skylight, are you thinking about getting one? If so, read this article on the 6 things to know about getting a skylight

How is the roof leak repaired? 

Repairing a skylight leak is a matter of taking the cladding (exterior aluminum armor around the glass that offers protection from the elements) and flashing kit off, putting an ice and water shield around it, and then putting the flashing kit back on.

That will give it the watertight seal needed to keep water out.

If you have multiple skylights, I recommend reflashing all of them at the same time. If one wasn’t installed properly, chances are the other weren’t either. 

If a skylight has reached the end of its lifespan you may only have to change out the factory seals, but usually, you’ll have to get a skylight replacement. 

How much does it cost to repair the roof leak?

To change out the factory seals, it’s going to cost around $500 per skylight. To reflash the skylight, it’s going to start at $750 and go up depending on size and roof complexity. 

To learn how much your new or replacement skylight is going to cost, read this article on how much your new skylight will cost

Find a great roofing contractor for repairs by asking the right questions

Now you have an idea how much it’ll cost to repair your leaky roof. Remember, these are rough estimates to fix the most common roof leaks. 

These repairs can extend your roof’s life and get you through until you need a roof replacement. But if you hire the wrong roofing contractor, these repairs will mean nothing and can even cause more damage to your roof and home. 

That's why we developed a checklist to help homeowners like you make the right hiring decision. The checklist gives you the 16 questions every homeowner needs to ask a roofing contractor and the right answers you should get back. 

The last thing you want is to be taken advantage and throw your money away, get the checklist now. 

The team at Bill Ragan Roofing has helped extend the lives of roofs all over Nashville with high-quality roof repairs since 1990. If you're local to Nashville, don't hesitate to contact us to help with any of your roofing needs. 

Get your Checklist of Questions to Ask a Roofing Contractor

checklist of questions to ask a roofing contractor

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