Chimney leaks are a hot topic during the spring and summer months.
Most of the time, they happen during the colder months and you’ll start noticing you have a leak a few months later.
Since they’re so common, I wanted to put together this resource page to help you understand why your chimney leaks.
And also to help you understand things you can do to help keep your chimney from leaking in the future.
How Do I Know My Chimney Is Leaking?
Chimney leaks are actually a pretty common occurrence.
That is likely because there are so many of the problems that can arise from a leaky chimney.
You probably suspect that the only way to tell if your chimney is leaking is by seeing or hearing water dripping.
That one is a pretty obvious indication that your chimney is leaking.
Unfortunately, seeing or hearing water leaking means that the water has penetrated through and there are some extra problems with your chimney that need to be repaired.
Because of the size and complexity of your chimney system, leaks often go unnoticed until they’ve caused significant damage.
Here are a few signs that may indicate your chimney is leaking:
- Water or condensation in the firebox
- Sound of dripping water
- Moisture, leak, or water staining on the walls or ceilings around your chimney
- Musty dank odors, especially after it rains
- Cracked or spalling interior or exterior masonry
What Causes Chimney Leaks?
Your chimney could be leaking from any number of things. Luckily, it can be narrowed down to five reasons.
If your leak isn’t from any of these five items, then your leak probably isn’t from your chimney.
#1 – No Cap
Chimneys without caps or something to cover the opening at the top, will have water falling straight down into the flue.
#2 – Crown is Cracked
Your chimney’s crown is the cement part on top of your chimney.
Bricks go around the flue, and the cement on top is used to help keep water, snow, and other debris from penetrating the bricks.
Cracks in the crown can occur from shifting the structure or from shrinkage that dates back to the day the crown was put on.
Or cracks can come from freeze/thaw cycles during the colder months. As water penetrates, it freezes and creates cracks in the crown.
No matter how the cracks get there, the water can easily go right through the cracks to leaking into your chimney.
#3 – Condensation
When it’s cold outside and warm inside (or even the other way around), you’ve probably noticed your windows fogging up.
That condensation can easily occur inside your chimney.
This is pretty common with unlined chimneys or chimneys without an insulated liner. Or even when the chimney isn’t lined with a properly-sized liner.
#4 – Flashing
The flashing is what is used to keep water from going into the spot where the brick on your chimney meets the shingles on your roof.
If the flashing isn’t sealed, there will be a decent hole that will allow the water to leak into the chimney.
#5 – Leaking Bricks
Bricks and mortar are porous. That means water can easily penetrate.
This seems like a huge design flaw, considering how weak bricks can become when faced with water.
The problem is the same as with mortar.
If water penetrates, it will go through freeze/thaw cycles, which will cause the bricks to crack. Those cracks will allow even more water to penetrate, causing even bigger leaks.
How to Prevent Chimney Leaks?
The best way to prevent chimney leaks is to have regularly scheduled maintenance.
That means you need to have your chimney inspected and cleaned every year by a CSIA trained and certified professional.
Since chimney leaks don’t just happen all of a sudden, they’re usually caused by a few problems that build up to a leak.
In other words, they usually don’t just happen overnight.
Having an inspection and a sweep will allow you to identify any new chimney or masonry damage, allowing you to repair anything before it leads to a bigger chimney leak.
Another way to prevent a chimney leak is by waterproofing your chimney.
At Patriot Chimney, we use a water-based waterproofing agent that coats the bricks. Since bricks are porous, they allow water to seep into them.
Since our waterproofing agent is water-based, that means the bricks will allow the agent to seep in as if it were water.
Then it coats the inside of the bricks and protects them from any more water penetration.
What’s cool about the material we use is that it keeps water from getting into the bricks as well as allowing any water already in the bricks to evaporate out.
How Much Does it Cost to Fix a Chimney Leak?
The most unfortunate answer is “It Depends.”
And when determining the costs to fix a chimney leak, the answer must be “It Depends.”
There are so many different things that can cause a chimney leak, and so many different solutions to fix them.
The best way to go about this to use a HomeAdvisor study from 2020 that compiled information from over 4,000 homeowners to give the average prices for leaky chimney repair work.
The average chimney repair costs between $160 to $750, but you could pay as much as $1800.
Even though this gives a pretty decent overview of the expected costs, it should be noted that these are just averages.
And every repair job is different. The amount of damage, the size of your chimney, the location of damage, and plenty of other factors will affect the overall price of your leak repairs.
At Patriot Chimney, we offer a “Leaky Chimney Bundle” that allows us to put on a new cap, repair the flashing, waterproof your chimney, inspect your chimney (with a camera view inside your flue), and repair your crown for $1000.
There are some terms that apply to qualify for this bundle, but that’s our most common solution to fixing chimney leaks.
Learn more here: Leaky Chimney Bundle
How to Find Chimney Leaks?
Sometimes finding a chimney leak can be very difficult. They can come from nearly anywhere on your chimney and are very tedious to find.
Finding a leak requires you to have at least two people. If you’re able to have more, then that’s better. The more, the merrier.
Be warned: this takes a long time.
- Cell phones or walkie talkies to communicate between each other
- Water hoses with shut-off nozzles on the roof
- A roll of clear plastic that is long enough to wrap around the chimney 2 or 3 times.
- Good shoes that can grip the roof and a safety harness (Safety first!)
- A yellow lumber crayon
Once you have all the materials and a few friends to help, simply follow these steps:
#1 – Wrap the Plastic
Start at about 1/2 inch above where your chimney meets your roof. Wrap your chimney with the clear plastic all the way around to a point that’s about 18 inches up.
Cover the chimney bricks while leaving the flashing around the base exposed.
#2 – Run the Water
Have someone inside the attic or just inside the house if the attic is inaccessible. Have this person watch the ceiling.
Run water from the hose down the roof along the lowest side of your chimney. Keep the water running for two minutes in the same spot before moving it.
Don’t splash water on the chimney or direct it up under the base flashing.
Have the person in the attic report the first drop of water seen.
As soon as the water is reported, use the yellow lumber crayon to mark the spot where the hose was pointing at this time.
If there is no leak on the front or low side of the chimney, move the water down one shingle at a time.
Pause at least one minute at each shingle as you move up the roof shingles on that side of the chimney, but be sure not to let the water go behind the chimney just yet!
Keep repeating this process one shingle at a time.
#3 – Repeat
Once you’ve completed all the water testing on the front side of the house, repeat the whole process on the other side of the house.
I told you this is a tedious process!
#4 – Remove the plastic
At this point, if you haven’t found any leaks, then it’s likely the leak is higher than the base flashing or nearby roofing shingles.
Remove the plastic wrap and reapply it so that the bottom edge is just above the uppermost piece of flashing, which is the vertical pieces of metal.
The plastic at this point is simply to make sure the water is not accidentally sprayed higher than it should be.
Starting at the front and working your way to the back section, run the water around the chimney with the observer keeps watch for the leak.
If there’s no sign of leakage just yet, the leak must be confined to the crown, mortar joints, bricks, or cap.
#5 – Check the Crown, Mortar Joints, Bricks, and Cap
All you need to do at this point is to move the plastic and hose down the chimney, following the same pattern of water application on each brick until you find the leak.
If you haven’t found a leak at this point then it has to be the mortar cap. Apply water there to make sure.
Are Chimney Leaks Covered by Homeowners Insurance?
If you have a leak anywhere on your roof, including your chimney, your homeowner’s insurance should cover any damage inside your house.
But getting the insurance company to fix a leaky chimney may be a long shot.
If water leaks through your chimney and rusts your fireplace irons or floods into your living room, the interior damage is covered.
But since it takes a while for chimney leaks to occur, and is pretty easy to prevent, your insurance isn’t likely to cover anything.
This, of course, doesn’t include sudden damage from a storm or if a tree blew against it.
For more information on homeowner’s insurance and chimneys, check out this guide: Ultimate Guide to Homeowners Insurance and Chimney Repairs
How Can I Hire a Chimney Company
Chimney leaks can be a pain.
They can wreak havoc on your chimney if you’re not careful. Luckily, all of this can be avoided if you make sure you have regular maintenance on your chimney.
A regular inspection, at least, will allow a chimney professional the ability to gauge how well your chimney is holding up.
You can easily reach out to your local chimney company and have a done-for-you solution in no time!
But navigating through all of the chimney companies in your city can be a chore all on its own. And it makes sense, too.
Hiring anyone to come into your home to fix something like your chimney shouldn’t be a task you take lightly. So I created a list that you can use to make sure you make the right decision when you need someone to help you in your home.
Questions to Ask
When you’re hiring a chimney company, you should always ask the following questions before allowing them to come into your home:
- Can the company provide references?
- Does the company carry a valid business liability insurance policy?
- Does the company ensure that a certified chimney technician will be on the job?
If they guarantee all three of those, then you are in a good spot. The technicians don’t necessarily need to be certified by the CSIA, but I do recommend putting in a bit more due diligence before accepting a certification that’s not by the CSIA.
This is because certifications are a tricky thing, especially in an unlicensed industry like ours. Any company can craft a list of job-related questions and sell them as an exam and certify those who pass.
I recommend you take a few extra minutes in your research before making your hiring decision to learn more about the certification the company has. Here are a few tips to make sure the certification is reputable:
- Is the word “certified” just part of the business name or is it an earned designation?
- Is the certifying body a for-profit business or non-profit?
- Does the certification need to be maintained and renewed through continuing education as the industry evolves, or is it well enough to be certified through a one-time exam?
- Is the certifying body well-established or are they relatively new to the scene? New doesn’t mean “bad” but you should make sure the requirements for certification are more or at least equally stringent as those of more established certifications
- Is the mission statement of the certifying body focused on educating and protecting homeowners or is it more focused on making it easier to earn a certification?
- Does holding the certification require following a code of ethics?
If you can answer all of these questions, then I think it will be safe to allow the company in your home to work on your chimney.
Please note that If you are hiring a chimney company to install a cap for you, most of the time, they will need to buy the cap themselves. This is primarily for liability and insurance purposes.
Besides, it’s probably cheaper for them to buy a cap at the dealer discount than for you to buy one at retail cost.
It doesn’t matter if you are in Roanoke, Lynchburg, Blacksburg, or some other city anywhere in the USA — if you have any questions about the safety of hiring a chimney company, please don’t hesitate to email me at firstname.lastname@example.org or call me at 540-225-2626. I’m happy to help!