English Sweep’s Chimney Waterproofing Services Will Save Your Chimney & Won’t Affect the Look of Your Masonry

The rain taps at your kitchen window while the first pot of coffee brews. It’s quiet and peaceful, save for the thunder cracks booming in the distance. You go to light a fire in your fireplace – confident that, because you were proactive with your maintenance and system upkeep, everything is well-protected and running smoothly.

After all, would you rather wait for a problem to pop up and then deal with the costly aftereffects, or take action ahead of time to prevent the problem altogether? The answer may seem obvious – who wouldn’t want to stop a problem before it occurs?

That said, not all homeowners use this same logic when weighing the benefits vs. the costs of waterproofing their chimney.

What Is Chimney Waterproofing?

Waterproofing is the process of protecting your masonry chimney against damaging moisture, so that rain, ice, sleet, and snow don’t ever get a chance to cause widespread deterioration. It’s easily the most effective way to prevent chimney leaks and water damage altogether – potentially saving homeowners hundreds, even thousands, of dollars on repairs. And fortunately, if you live in the general St. Louis, MO area, English Sweep, Inc. is just the team to call to ensure your chimney can weather any condition – no matter how severe.

Need help with something else hearth-related, like scheduling your annual chimney sweep service or comprehensive inspection? We can help with that too.

Get in touch with someone from our team by filling out this appointment request form right here on our website or by giving us a call at 636-225-3340. We look forward to working with you!

Water Repellent Spray on red bricks with applicator

Water-Repellent Spray on Bricks

Water beading on bricks after application of sealant

Water Beading on Bricks

How Does Chimney Waterproofing Work?

So, how does chimney waterproofing work, exactly? We apply chimney-specific waterproofing products to your masonry that ensure water pools up and rolls off, rather than soaking into the brickwork.

One of the biggest ways waterproofing helps is by preventing the freeze/thaw process. The freeze/thaw process is what happens when water soaks into the cracks in your bricks, freezes, and then expands and makes those cracks even bigger. This leaves room for even more water to enter when things heat up again. And thus, the cycle continues.

Here in St. Louis, we’re no strangers to freezing weather, so this process usually occurs many times a season for chimneys that aren’t protected. And the more it happens, the more your system is at risk for further damage and deterioration.

How Long Does Chimney Waterproofing Last?

Well, it depends. It’s a bit tricky because waterproofing is one of those things that many homeowners believe they can handle themselves. Sure, there are a variety of waterproofing products available for purchase at local hardware or home improvement stores, but that doesn’t mean they’re high-quality and long-lasting.

The results of these waterproofing products might provide a few years of semi-decent weather protection, but will pale in comparison to what you get from a professional product applied by a professional, certified technician.

Generally speaking, most professional chimney waterproofing agents have a built-in warranty for anywhere between 5-10 years…as long as the product has been applied by a professional, certified technician. Remember to keep track of this service, though, and stay on top of scheduling a re-application when you near the end of your warranty period, so there is no lapse in full-coverage weather protection.

Questions? Want to know more about proper maintenance or what the waterproofing process looks like? Worried about your structure and its current state? We can ease your mind and answer it all, all you have to do is reach out! You can set up an appointment with us online, or give us a call at 636-225-3340; we’re happy to help in any way we can.

Tackling Waterproofing Myths

Myth: Bricks need to breathe, and therefore shouldn’t be waterproofed.

This is partly true. Bricks do need to breathe so that any pre-absorbed moisture can effectively get out, along with any fireplace-related fumes and vapors. The great thing about the products we use is that they’re vapor-permeable, which means no stressing about moisture that’s already in your masonry – it will be able to escape, no problem. And perhaps the best part about these sealants is that they’re known for protecting your brickwork without affecting the look of your system at all.

Myth: My chimney’s been fine for years without waterproofing.

Bricks are strong and sturdy, yes. But that doesn’t mean they won’t face wear and tear with time. Water is one of the more harmful substances they can interact with. Just because your system looks fine doesn’t mean everything is A-okay. In fact, we’re guessing some cracking and deterioration is already present – just hidden away – and this will only worsen over time. If you’re looking to keep your chimney strong for the long haul, waterproofing is a must.

Myth: I have enough preventive measures in place already.

There are a lot of things out there that help to keep your chimney system protected against water. Chimney caps play a big part in this, as do well-built chimney crowns and properly installed flashing. If you already have all of these things in place, you may think your chimney is protected enough. Will one more service really make that big of a difference?

The fact is that all of these things are important, and they all work together to protect different areas of your chimney and masonry. But waterproofing is equally as important as all of the rest! Nothing protects your masonry against moisture and the dangers of close contact with water like waterproofing.

Myth: If I waterproof my bricks, repairs aren’t necessary.

If your brickwork or mortar is damaged at all, you’ll need to make repairs before you waterproof your structure. This is because water damage doesn’t just affect the appearance of your chimney – it also causes structural concerns.

What Happens if I Don’t Have My Chimney Professionally Waterproofed?

If you don’t have your chimney properly weatherproofed by an experienced and knowledgeable expert, there are a couple different scenarios that could occur, neither of which is great.

Scenario 1: You don’t have your chimney waterproofed at all. 

We’ve already debunked the myths of chimney waterproofing and gone over why this specific service is so vital. Without some kind of waterproofing solution for your chimney, it simply doesn’t stand the test of time.

As one of the more porous and permeable building materials available, bricks can hold onto a lot of moisture. Did you know that a single brick can absorb up to a cup and a half of water if allowed to be fully saturated? This means that an average sized chimney for a one-and-a-half story home could retain roughly 1000 pounds of trapped water weight. Just for reference, that poundage is equivalent to a full grown bull…distributed only throughout the brick of your chimney, which naturally could cause some serious foundational problems to your entire home should the structure begin to pull away.

Which would you rather do: invest in the professional waterproofing services from the get-go or risk your entire structure collapsing or detaching from your home? We’ll give you a hint which one is more affordable…and it’s not the reactive approach.

Scenario 2: You purchase your own waterproofing products and do it yourself. 

Okay, in comparison to the former situation, this one is obviously preferred. However, like we went over earlier, the products that you can find online or in your favorite nearby stores simply are not to the same caliber as the ones we use in the industry.

It takes a very specific blend and ratio of the right materials, components, and an awareness of their individual properties as well as how they interact with each other to create a product that works and stands the test of time and a variety of weather conditions. A good chimney waterproofing product must not only preserve the look, feel, and overall natural integrity of the brick, but it also must effectively protect without completely sealing it all off.

The truth is that the only products out there that can do all of this – and do it well – are the ones that require industry knowledge, expertise, and certification to utilize.

But, that’s where we come in. At English Sweep, we only hire the best of the best; the technicians who are not only friendly and approachable, but are also highly trained, qualified, and certified with the best organizations in the industry, like the Chimney Safety Institute of America (CSIA).

For excellent chimney care in or around St. Louis, MO – including these necessary waterproofing services – there’s no one better than English Sweep. Give us a call at 636-225-3340 – or reach out online – and see for yourself!

What’s the Best Time of Year to Waterproof a Chimney?

While it doesn’t necessarily matter exactly when you schedule your waterproofing service, we do usually suggest scheduling for sometime in the spring or summer before the burning season begins in the fall. Mostly this is just because that’s when we’re the busiest – everyone is using their fireplace and we often have to troubleshoot or perform repair work.

It’s the same reason we like to recommend the same timeframe for other preventive services like annual chimney inspections or cleanings – you have a better chance of securing a slot in our schedule rather than settling for a lesser rated company.

Also, even though it doesn’t snow a whole lot here in St. Louis, it’s much easier to do any kind of external chimney work before the temperatures start freezing. That being said, we can and will waterproof your chimney any time throughout the year, so long as our schedule allows!

How Much Does It Cost To Waterproof a Chimney?

Honestly, it depends. Sure, one of the biggest factors that affects the overall cost of the service is the size and length of your masonry chimney, but it’s not the only thing to consider. We also have to figure out the state your system is currently in and assess whether or not there is existing damage that would need to be repaired before we can move forward with the waterproofing process.

Unfortunately, this industry can vary so greatly when it comes to price expectations because just like every house is a little bit different, so too is every chimney.

However, we pride ourselves on being upfront and honest with all our business practices – including our pricing. Once we have more information from you, we’re able to provide you with an approximate estimate. Give us a call or reach out online, and we’d be happy to discuss the process, pricing, and other expectations!

Convinced & Ready To Get Started? Call the Pros at English Sweep, Today!

If you’re ready to invest in waterproofing services, it’s time to call on our team. We’re known throughout St. Louis County, Washington County, St. Charles County, and more for being professional, reliable, and solution-minded.

We’re here to offer effective chimney waterproofing services that keep your structure protected for the long haul. And since our crew holds certifications with the CSIA and the National Fireplace Institute (NFI), you can trust that we know our stuff.

Get started with booking your appointment – call 636-225-3340 today.


Troubleshooting leaky chimneys often uncovers the need for chimney crown repairs. Lucky for you, we know what to do!