Why are my chimney bricks spalling?

Jun 26, 2020Chimney

Just like other areas of your home, chimneys too can have different problems and defects, making them less efficient and unsafe to use. One of the most common obstacles you might run into is spalling.

Most of the time, spalling is a result of water seeping into the brickwork. The moisture that keeps developing with time forces the chimney bricks to peel, crack, pop out, flake off, or crumble. If spalling goes untreated, it compromises the entire structure of the chimney.

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Spalling starts as minor cracks and develops into bigger ones deteriorating the entire surface. Once spalling arises in a particular location, it risks even the bricks of surrounding areas. That’s why it’s so important to fix the problem as soon as you see it.



1. Water

Water is one of the underlying causes of spalling. It affects the material in several ways. Number one is rainwater that directly hits the surface and eventually begins to degrade the brickwork. Next is poor drainage of water that can, over time, erode the bricks of the chimney. Water may even directly enter the insides of the chimney due to broken or cracked crown. A colder climate can also freeze and thaw the bricks leading to excessive damage. In fact, moisture can seep into the bricks through something as harmless as water vapors. And in case salvaged bricks have been used during the construction of the chimney, spalling is more likely to occur.


2.Harsh Weather Conditions

Another major cause of the spalling of chimney bricks is the environment. The detrimental effects of rain, wind, heat, hail, and snow can worsen the exteriors. That dramatically changing climate pierces the protective layer of the bricks resulting in progressive damage. Such destruction tends to enlarge with time, and the bricks or the masonry falls apart.


3. High-Pressure Cleaning

This is another reason why bricks start to spall. High-pressure washing leads to considerable damage to the bricks. It is especially harmful to chimneys that are harder on the outside but have a softer core. Moreover, it even strips the waterproofing sealant used for the bricks.


4. Non-Breathable Sealants

If you’ve been using non-breathable sealants, let us tell you that they’re working just the opposite of their nature. Chimney brickwork is good at absorbing and releasing water through the actual pores. But with an inappropriate sealant, you’re blocking the pent up water from releasing. This leads to the water remaining trapped indefinitely.


5. Risky Construction

Builders sometimes use softer bricks in place of the hard ones for constructing various structures in homes, including the chimneys. The former choice is relatively inexpensive, but unfortunately, it’s more vulnerable to moisture penetration. If, in case that’s the kind of damage you’re experiencing and rebuilding is the only feasible option, we can certainly use hard bricks to make sure that your chimney lasts longer.



If you’re wondering why your chimney masonry is worse off than the masonry on other areas of your house – the answer is simple. The kind of exposure, usage, and wear and tear that chimneys contain make them the first areas to show damage than the rest of your property. As the above causes explain, chimneys are more open to harsh indoor as well as outdoor environments. By the time you visibly notice chimney bricks spalling, severe damage might have already pestered the safety and appearance of the chimney’s construction.



When you start noticing the signs of spalling, including discoloration, cracking, crumbling, missing chunks, flaky surface texture, and bulging, etc., take the necessary steps. Call an expert! Fixing the problem usually depends on how much damage has been caused. Following are some of the ways in which the condition of your chimney can be restored:

  • a. At first, the technician might repair the chimney crown.
  • b. They may add, repair, or replace the chimney cap.
  • c. To avert water away from your chimney, they can have a cricket installed.
  • d. For preventing moisture from trapping in the chimney bricks, a breathable sealant will be finished off with.
  • e. They may use fresh mortar to restore the chimney to its original level of stability

If the issue is taken care of at the beginning itself, the problem will not aggravate, and the solutions will be quick and straightforward. Even if you identify the damage in the later stage of spalling, when the brickwork has significantly been deteriorated, fixing can get time consuming and expensive. However, all these efforts would only prevent future risks.

Also, we don’t recommend you to use the chimney under such circumstances. Cracks or gaps in the structure can allow the harmful carbon monoxide fumes to enter inside your property and make the areas unsafe to love. Until an expert hasn’t assessed the full impact of spalling, stop using the chimney.



The best way to address the spalling of the chimney bricks is to take preventative measures. Whenever you observe this problem, opt for the best repairing services ASAP! If the condition isn’t addressed, the chimney structure can crack and crumble. One of the best DIY ways is to apply a breathable sealant to prevent the buildup of moisture. It may also be tempting to cut corners, replace just a few majorly damaged brick, or partially rebuild the chimney. But that won’t alleviate cracking and breaking off the chimney bricks along with any other fundamental damage (if any).

These are just temporary fixes. For a more effective and long-term solution, you’ll have to seek professional help for experts who are specialized exactly know how to accommodate your needs.

Talk to our specialists at Elegant Fireside and Patio and schedule an annual inspection. Such regular checks are mandatory as they help identify trouble spots beforehand and prevent costly chimney damages later on. And regardless of how you choose to address the problem of spalling, hiring a professional will maximize safety and ward off any havoc that can be created in your home’s chimney system.

If you’ve noticed spalling on your chimney bricks, contact us at Elegant Fireside and Patio today. We have a team of qualified and dedicated technicians who can help you with chimney cleaning, relining, repairing, rebuilding, and water sealing services. Let us put our three decades of experience to work for you!

Call us at (972) 846-4878 – we’re located at West Parker Road in Plano, Texas, and provide a wide range of chimney services. You can also contact us online for more information on Chimney and other related services. You can visit our social media for more details.


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