Top 6 Common Exterior Chimney Problems

#1 – Damaged Masonry 

One of the biggest design flaws in construction is that bricks are extremely porous and do a horrible job keeping water out. 

Once moisture works its way into your masonry, the water has an opportunity to go through various stages of freeze/thaw cycles. 

Freeze/thaw cycles have a horrible effect on bricks because it allows your bricks to start cracking and spalling. 

All of this just allows more water to penetrate into your chimney to cause even more damage. If this sounds like a domino effect to you, then you’re right. 

When water begins seeping into bricks, you will eventually need to schedule a repair. Your chimney will begin to lean and could eventually collapse. 

Old mortar is another way water can get into your chimney pretty easily. 

Much like bricks, mortar is a porous material that allows water to penetrate. Water that gets into mortar joints can cause cracks, more water, and eventually leaks. 

The best way to keep from having to rebuild your entire chimney is to tuckpoint and repair your mortar joints. 

We can finish that off by spraying a water-based waterproofing agent that allows water to evaporate from the bricks but doesn’t allow extra water to penetrate. 

#2 – Cracked Chimney Crown

At the very top of your chimney is what we call the crown. 

I’ve heard it called the chimney wash, but no matter what you call it, I’m referring to the large slab of concrete on top of the opening of the chimney. 

The crown is built to be at minimum two inches thick to be able to withstand all the elements of weather, such as rain, snow, hail, sleet, and anything else mother nature throws at us. 

But over time, wind and weather can have a real effect on the chimney crown. And eventually, it can start to deteriorate. 

Also, you can bet that the crown can go through the same freeze/thaw cycles that I mentioned before. 

If you ignore crown problems, you can easily see water seeping into your bricks and causing a whole new cycle of decay. 

Luckily, early on, cracks can be filled and sealed. 

And if your crown is too far gone, the good news is you may only need to rebuild the crown. Not the entire chimney.

#3 – Damaged Flashing

The flashing is like your chimney’s custom-made rain boots. Flashing seals the space between your roof and your chimney. 

As you can imagine, if the flashing isn’t properly sealed, water from your roof can easily find its way into your house.

In fact, the corner of your chimney is a particularly vulnerable spot. And leaving it unmonitored can result in significant damage to your ceiling and walls. 

Flashing can become damaged due to many different reasons, such as natural causes like weather and rust. 

And a very common source of damage is when you have a roofing company cover the flashing with roofing tar, which diminishes the effectiveness of the flashing. 

If we detect an issue with your chimney’s flashing during an inspection, we apply a sealant called “Flash Seal.” This will help us make sure your chimney is in prime position to not leak.

#4 – Excessive Creosote or other Blockages

Chimneys that are connected to wood-burning appliances can have build up in creosote, which is a sticky or flaky material that’s formed when the fire burns. 

Although creosote is naturally occurring, it is highly flammable. It’s also the leading cause of chimney fires each year in the United States. 

Most of the time, creosote will stick to the lining of your flue. 

But it’s not uncommon for us to see creosote so backed up that it actually clogs up around the opening of the flue. 

And it’ll cake onto the crown of your chimney and the chimney cap. 

Blockages from the outside of your chimney may clog the opening of the flue. For example, when leaves fall, they can get lodged into the cap causing a disruption in airflow. 

This may not seem like a huge deal at first. 

But you should realize that your chimney is a system that relies on airflow and draft in your home. What that means is that your chimney is essential in exhausting gases from your chimney towards outside. 

It uses the airflow from your home to push gases and smoke up and out of the chimney. 

If the airflow is disrupted, you risk having those gases pushed back into your home. 

In this case, the best scenario is that you have a room full of smoke. 

The worst case is that carbon monoxide, the silent killer, will be pushed back into your home. As you’ve probably heard a ton of times, carbon monoxide is highly poisonous. 

And taken in large enough doses, could be fatal.

#5 – Chimney Cap Damage

I like to think of chimney caps as the umbrella of your chimney. 

It may not protect your chimney from all water, but it will help keep it safe from getting wet from above. 

So while it helps keep water from getting onto your chimney, a cap will help keep water from falling directly down your flue, into your chimney box. 

Your chimney cap’s main purpose is to prevent rain, snow, animals, etc. and for preventing downdrafts. 

Since your cap is protecting your chimney, it’s no wonder that they can get damaged pretty easily. I mean, it’s taking the brunt of the force afterall. 

Your cap can become damaged pretty easily if it wasn’t installed properly, debris from surrounding trees, or extremely high winds that can blow the cap right off the chimney. 

Plus, your cap could be a lot more susceptible to damage if you don’t pick the right material. 

Galvanized steel and aluminum is cheap. It looks good, but they’re flimsy and only last about 5 years before they start to rust and deteriorate. 

If you want something that will last a long time (with a lifetime warranty), then you’ll want either stainless steel or copper. Both are durable, tough, and stylish.

#6 – Rusty Chimney Chase Covers

If you don’t have a masonry chimney, then you have a chimney chase cover. 

Much like the crown of your chimney, the chase cover sits right on top of your chimney. The most notable difference is that chase covers are made up of metal. 

Despite the difference in material, the functionality is basically the same. It’s goal is to protect your chimney from all the elements of weather, such as rain, snow, hail, sleet, and anything else mother nature throws at us. 

But over time, wind and weather can have a real effect on the chase cover. And eventually, it can start to deteriorate. 

Eventually, depending on the material of your chase cover,  you’ll notice brown streaks from the top of your chimney. 

This means that your chase cover has started to rust. 

Rust on your chase cover allows for small pinholes to form. Water can puddle on top of your chase cover and easily leak through the pinholes. 

If you ignore these problems, you’ll eventually have a lot of water built up inside your chimney. The rust will continue and get worse. 

And you could face decay in your foundation and in the chimney. 

Furthermore, if you’re not careful, mold and mildew can form and spread within your walls. 

Just like chimney caps, the material goes a long way. 

You can get a galvanized steel and aluminum chase cover. They’ll look just as good. But they certainly won’t last as long as one made from stainless steel or copper.

How to Hire, What to Look For

When you’re hiring a chimney company, you should always ask the following questions before allowing them to come into your home:

1. Can the company provide references? 
2. Does the company carry a valid business liability insurance policy? 
3. 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. 

Certifications

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.

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 mitchell@patriotchimney.net or call me at 540-225-2626. I’m happy to help!