Why You Should Consider Waterproofing Your Masonry Chimney

It no longer matters where you live; there is bad weather going on everywhere, unusually high heat, torrential downpours, tornadoes, fires, etc. If you have a masonry chimney there are few things that can be more damaging and annoying than a leak. That drip, drip, drip pinging from the top of the chimney to the firebox can resonate through the halls of your home and cause you to be extremely frustrated. Prevention is the best solution to this problem. That’s right, you can virtually stop the rain in its tracks by simply having your chimney waterproofed. But first, let’s learn a little bit about what water in your chimney can do and how it gets there.

The Bad News

Water alone causes over 1 billion dollars in damages to homes, businesses and other structures each and every year according to the latest insurance data. If you include the latest NOAA information to include floods it reaches in the 5 to 8 billion dollars per year! Now that we know how dangerous and devastating water can be, let’s look at what it can do to your chimney.

The first thing to understand is that the chimney extends far above the roof line, so it is totally exposed to the elements. This includes the bricks and the mortar joints and sometimes the crown on a masonry chimney or the chase and chase cover on a prefab. What many people fail to realize is most of this material is porous and can saturate over time. Add to this the freeze-thaw damage and natural deterioration and over time, you will have some type of structural failure.

Brick Chimney with damaged mortar joints
Damaged ceiling from leaky brick chimney
Efflorescence on brick inside house

The Good News

The good news is there are things that can be done to make sure your chimney is well taken care of and will function as needed in a safe and efficient way no matter what the season. The absolute best thing to do is waterproof your chimney. There are several ways to waterproof your chimney.  Installing a chimney cap is the first way.  It keeps water from directly entering the flue.  In addition to installing a cap, applying a water repellent to the bricks helps prevent excess water from penetrating through them.

Firesafe tech at work on roof waterproofing with two chimney flues and woods in background

What Type Of Waterproofing And Sealers

We recommend and apply Chimney Saver©. It is the product most certified chimney companies use out in the field. It’s important to know the difference between a product that waterproofs and one that seals. The ChimneySaver product is a water repellent, not a sealer. Sealers and silicone coatings create a water resistant coating that actually traps the water vapor. The trapped water vapor actually adds to the deterioration of your brick. Remember, the brick on your chimney needs to breathe. The ChimneySaver product we use is 100% vapor-permeable, thus allowing the masonry to breathe still.  This is very important for your unit to function properly.  ChimneySaver® has a 10-year warranty.  You can learn more about ChimneySaver® here.

Make Sure To Repair Before Waterproofing

The one thing you don’t want to do is waterproof the chimney before any needed repairs are done to the brick and mortar joints. This can easily be done in most cases. Spalled bricks can be taken out individually or in groups with new bricks laid. There is a technique called tuckpointing that is used to repair cracked mortar joints. There are some products on the market that can also be used if the cracks are not as bad. Discuss the options with your chimney professional first. They can help you make that decision. Contact us today!

Dampers are another way to keep water and debris out of your chimney system. Just another installation we do here at Fire Safe Chimney Sweep.