Chimney Repair – 4 causes of leaking chimney flashing

leaking chimney flashing

We recently were contacted by a customer in Silver Spring, MD who had a chimney that was leaking through the flashing.  This is a serious problem.  When water leaks into your home from your chimney, this can cause all kinds of problems. From water damage that seeps into your walls to shorting out appliances, chimney leaks are a problem for many homeowners.  Flashing is one of the most common sources of chimney leaks. There are many reasons that chimney flashing leaks, and it’s important to get this problem by a chimney repair company like ours right away before more significant damage occurs in your home. 

The Wrong Flashing Techniques Are Used

Incorrect flashing installation is a big culprit of roof leaks. We recently completed a chimney repair project in Silver Spring, MD that was caused by this problem.  Step flashing is necessary where the roof meets the wall, and beneath the flashing, an underlayment is needed that goes partially up the wall and along the roof.  This creates a solid barrier so that water can’t get through. The step flashing needs to be nailed onto the roof, and not against the wall. The counter-flashing has to be attached to the wall to account for wall expansion and contraction during weather extremes. Flashing that isn’t installed correctly isn’t going to work.

Old Flashing Needs to be Replaced

Over time, roof shingles and flashing can crack and break, requiring that the flashing gets replaced.  This is a common problem that we see when repairing chimneys in Washington DC.  While you may notice a small leak at first, flashing that is deteriorating will eventually lead to bigger leaks if it is left alone. Flashing gets ruined over time because of harsh weather conditions, and the expanding and contracting required during the weather extremes. While it is often made of galvanized steel, even steel can’t withstand harsh weather conditions forever.

The Seal Between the Flashing and Chimney is Cracked

Sealants are used to block water from entering your home between the flashing and the chimney. Sealants get dry and brittle over time, and they are prone to cracking. When a sealant is damaged, water will enter the home through the damaged sealant. If you don’t know how to replace the sealant on your chimney flashing, it’s time to call in a professional to repair the problem.

Water Damming at the Chimney

Sometimes shingles are not placed on the roof correctly, and this can cause water to dam up behind the chimney and seep into the roof of the home in this area. Even when the flashing is installed properly and not damaged, if water is not flowing off of the roof properly, water can dam up and cause problems with leakage.  We recently repaired this type of problem in a home in Ellicott City, MD.

When you have leaks in your ceiling that you can’t identify, it’s important to call in a professional to handle the situation. If you are unable to go on your roof to check for leaks, you need to hire someone to do this for you. When you ignore water leaks,


Chimney leak repair. Others failed. We Fixed It!

On May 18th, 2016 I went to Mrs. Irshad’s home in Silver Spring, MD to give her an estimate to fix a brick chimney that was leaking.  Her wood burning fireplace was working fine.  However, the brick chimney was leaking.  Before my visit, she had two other companies attempt to repair the chimney who were unsuccessful.  As she tried to contact the other companies to tell them that the chimney was still leaking, they brushed her off and never came back to address her issues.  As a result, she had paid for repairs and her chimney still leaks every time it rains.  When I arrived that day, she was very skeptical and didn’t think I would be able to help her, and I don’t blame her for feeling that since two other companies burned her before my visit. This job reminded me of a chimney repair job that we did in Potomac, MD earlier this year. 

After introducing myself I asked where the leak was coming in, and she showed me that the water would leak in her garage from the ceiling. Then I asked what the previous companies had done to try to fix the problem and let me just say that some people have no business doing this type of work. I feel bad for Mrs. Irshad because she spent her money with these companies to fix a problem and once they got paid to do the repairs which weren’t even proper fixes they never came back to help her address the leak.

The first thing I did to evaluate the leak was pulling out my hose and perform a water test on the flashing. I was already pretty sure that the flashing was the issue based on where the leak was coming from.  Leaking flashing is one of the common causes of chimney leaks. Based on the water test I was able to confirm that the leak was coming from the flashing. At that point I was 100% confident that the job required chimney flashing repair.  This also reassured Mrs. Irshad that the flashing was indeed the source of the problem and made her feel a lot more comfortable about the repairs I recommended. Here are some pictures of the job from start to finish. 

This is during the site visit where I water tested the flashing and found out it was the source of the leak. 

leaking chimney flashing

The other companies tried to fix the problem by applying silicone over the old seals on the counter flashing. 

bad chimney repair job

They also decided to put painters tape on the roof and siding and tar over it. This is just a horrible attempt at fixing the problem. It shows that this person had no idea what he was doing. The issue was actually where the arrow is, for some reason it was missing flashing in that area.  

missing chimney flashing

Once I removed the tar and blue tape, I found that the inside corner was missing flashing.  The customer told me that when they applied the tar, it slowed the leak down a little bit which makes sense since it was missing flashing. 

tar paper and base flashing installed on chimney

We removed the shingles and both the counter and base flashing. We then installed tar paper and new base flashing and shingles. 

base flashing and shingles installed

Here we have the base flashing and shingles installed. 

after chimney leak repair

This is the finished product we installed the counter flashing into the mortar joints and then sealed it. We’ve had some heavy rains since the repairs were made and Mrs. Irshad has had no leaks since!

Completed Gas Fireplace Installation

We were contacted by Mr. & Mrs. Vincent because they wanted to install a gas fireplace insert into the existing fireplace of their home. The existing fireplace is original to the house which dates back to 1900-1920’s and is no longer functional as a wood burning fireplace.  After considering how easy it is to maintain a gas fireplace and these additional benefits of gas, they decided not to install another wood burning fireplace. One of the requests made by the homeowners was to use the existing mantel with the new fireplace, which is why we ended up with the Enviro Q1 gas fireplace insert. We had recently installed the same unit in a home in Silver Spring, MD.  This unit can be used as a gas fireplace or an insert…, this was perfect for this situation.

Let’s take a look at how the fireplace was installed.

Before we started the fireplace installation

open fireplace

The first thing we did was clear the work area, set our drop cloths, then removed the mantel and set it aside.

 fireplace installation

This is what was underneath the Durock and marble.

fireplace repair

We took out the bricks to make room for the new hearth support.

fireplace hearth repair 

We installed the new hearth support by securing it to the existing floor joists.

hearth support installation

We then installed 1/2″ sheathing and had the gas line and electric ran on the back left of the fireplace.

 fireplace gas line installation

On top of the sheathing, we installed two pieces of 1/2″ Micore and Hardibacker to meet the required 2.27 minimum R value for the hearth. This is the first layer of Micore.

 fireplace hearth installation

This is the 2nd layer of Micore.

micore layer fireplace

This is the layer of Hardibacker.

 2nd layer of micore

This is the new slate hearth on top. The floor on the house was level left to right, but it was slightly off level front to back (not bad for a house that’s nearly 100 years old!)

slate fireplace hearth installation

Here we have cut back the drywall and are dry fitting the slate surround to go around the fireplace.

 fitting slate for fireplace install

Slate surround installed and ready for the mantel to go back on!

slate fireplace surround installed

Finished Fireplace Installation

finished gas fireplace installation

Here is the finished product! We reinstalled the mantel and installed trim around the slate hearth.  *The flame is blue because this picture was taken within the first few seconds that the fireplace was turned on, it turns orange after a  few minutes.  

You can see images of other fireplace installation and chimney repair projects here.  

Related Articles about Fireplace Installation

4 Significant reasons to install a gas fireplace

Amazing Baltimore, MD fireplace installation

Recent fireplace installation in Germantown, MD


9 Common Causes of Chimney Leaks

We recently provided chimney repair services in Silver Spring, MD on a home with a chimney leak.  This time of year we encounter more chimney leaks than during the drier season.  It’s common to have your chimney develop some leaks.  The scariest part of it is that you can have a chimney leak without realizing it.  Unknown leaks can lead to potential hazards and costly repairs if left untreated, so it’s important to have a regular chimney sweep and inspection done by a certified chimney repair company. Some types of chimney leaks are not as dangerous, but they still cause damage to your home because moisture gets where it should not be. Here is a short list of the most common causes of chimney leaks:

 No cap or cover on the chimney

 repair missing chimney cap

 A chimney that is open to the sky lets rain and snow fall inside and cause that wet campfire smell to permeate the room. It also gives animals and birds opportunities to build nests. Things pile up, and your chimney could be blocked, leaking carbon monoxide into the ho

Damage to the chimney crown

chimney crown damage

That sloped layer of concrete, the chimney crown, is what keeps water from damaging the mortar in the bricks beneath it. It also seals the gap between the liner and the outside chimney. When it has little cracks, the freeze-thaw effect makes those cracks grow bigger. It’s like losing shingles on the roof.  If your crown is damaged, there will be leaks.  We witnessed this problem with a chimney repair project in Ellicott City, MD Be sure to read this article on repairing chimney crown cement

 Deteriorated or improperly build chimney shoulder

chimney repair

 The shoulder of the stack, the sloped area on the stack where it transitions from a broad base to narrow, is a common area where the masonry deteriorates and is the cause of leaks, or it is just not constructed well enough to hold off rain and snow.  Here is an example of a chimney in Columbia, MD that was poorly constructed resulting in leaks.  Often it is built without a proper pitch to allow the water to run off, and as a result, it soaks and leaks its way into the chimney.  

 Deteriorating mortar & masonry

damaged chimney

The Chimney Safety Institute of America says water and your masonry chimney is a dangerous mix. The result of prolonged water contact rusts metals in the stack structure, and the porous masonry holds water that allows mold in warm situations and the freeze-thaw effect when it’s cold breaks down the integrity of your building.  We frequently see this problem when doing chimney repairs in Washington DC. 

 Inadequate flashing

chimney flashing repair
The flashing is supposed to be the flexible connection between your chimney and roof that lets each side expand or contract without making a gap between them. If the flashing needs to be repaired or replaced, you will see leaks around the chimney.  This is a common problem in Washington DC.

 Rusted chase cover

chimney leak silver spring, md

 Often when the builders install prefabricated fireplaces, they will install a galvanized chase cover which sits flat on top of the chase. When snow sits on top of it, it weighs it down and allows water to puddle up causing the galvanize chase cover to rust out and allow water to leak into the house. A certified chimney repair company can install a new stainless steel chase cover which won’t rust and is pitched to allow the water to run off.

 The wrong chimney liner


 Your chimney liner must be sized based on the appliance it’s serving, if the flue is too big for the device(s), the flue gasses will condensate. For wood burning appliances, this means excessive creosote build up which can lead to chimney fires and for gas appliances this means moisture build up in the flue system which can cause the masonry to deteriorate and cause the moisture to leak out into the house. A certified chimney repair company can reline your chimney with the right size liner.

 You need a chimney cricket
chimney cricket installation

“Cricket” is the term for a water deflector that is installed where the roof rises from the chimney. It is an excellent idea for a steep roof or chimneys more than 30 inches wide. As the rain runs down the roof toward the chimney, the cricket moves the water to the sides and on down to the gutter.

 There’s a clog in your chimney


 Leaky chimneys can cause moisture damage to the point that bricks fall into the chimney and clog it up (commonly seen in older homes that are not lined) or an animal builds a nest in the chimney clogging it up. Whatever the case maybe, if the chimney is clogged there is a problem with the airflow, which could result in no heat and hot water or a more severe type of leak — carbon monoxide.

So how do you keep these causes of chimney leakage from causing trouble? By making sure, you have a regular chimney inspection by a reputable chimney repair company. That way, the source of the leak is identified by the people who know what the problem is and can fix it. No matter what kind of leak you have in your chimney, letting it continue to be there guarantees your problem will get worse.