A cracked chimney can result from moisture, freezing temperatures, house settling, chimney fire, or construction flaws. Some common types of cracks include horizontal, vertical, hairline, and stair-step cracks. While not all are immediately dangerous, ignoring them can lead to water damage or even chimney collapse.
Understanding the causes of chimney cracks is crucial for maintaining the safety and integrity of your home.
Your masonry is constantly under assault from moisture. Throughout the entire year, rain and humidity introduce moisture to your chimney, both on the exterior and the interior. Moisture that seeps through the porous bricks slowly erodes them over time, resulting in cracks and overall damage.
During the winter season, moisture can be exceptionally harsh on your chimney. In addition to moisture from snow and rain, frigid temperatures can cause the trapped water to freeze inside the bricks.
When water freezes, it expands, which leads to a cracked chimney. As the chilly season continues, these cracks happen more frequently. Just one rough winter can cause significant damage to the masonry of your chimney.
Extreme winters can cause catastrophic damage to your chimney, ultimately leading to a collapse. Many homeowners understand that they need to watch for issues like frozen pipes, but it’s equally as important to keep an eye on your chimney and fireplace when temperatures consistently drop below the freezing point.
Over time, as older homes settle, your chimney may begin to lean or develop cracks. This settling can range from minor cosmetic issues to severe problems, including the potential for the chimney to collapse or an increased risk of fire. If you notice your chimney is tilting or pulling away from your house, it’s essential to contact a repair professional immediately.
The concrete foundation beneath your chimney is vital for its stability. If this foundation begins to fail, even slowly over time, it can initiate a chain reaction of cracking that will continue until the chimney eventually collapses. Chimney cracks can often be an early indicator of a compromised foundation.
Chimneys constructed with poor-quality materials or inadequate building methods are inherently more vulnerable to cracking. The inherent weakness in these materials makes them less resilient to the various stresses a chimney endures.
In regions prone to seismic activity, sudden stress from earthquakes can lead to cracks or even the collapse of chimneys, particularly if the structure lacks proper support. Similarly, lightning strikes can inflict sudden and severe damage, causing cracks due to the immense force and heat.
The intense heat generated by a chimney fire can exceed the capacity of the chimney materials to withstand it. This extreme thermal stress can cause rapid and severe cracking, compromising the structural integrity of your chimney.
Chimney damage can take many forms, and recognizing the different types of cracks and deterioration is the first step to maintaining a safe and functional chimney.
Even small cracks in your chimney can lead to larger structural issues over time. Once the masonry is compromised, water and moisture can enter through the openings, causing further deterioration and damage. If left unaddressed, these cracks can escalate into major safety hazards, including the potential collapse of the chimney.
Unfortunately, your chimney is one of the elements of your house that is permanently exposed to harsh weather conditions, however, there are some steps you can take to reduce the impact of weather on your chimney to minimize the risk of further damage as much as possible.
Here are some recommendations on how you can prevent a cracked chimney from our CSIA-Certified experts.
One of the best ways to keep moisture out of your chimney is to invest in a top-sealing damper. These specialized dampers have a rubber gasket seal that forms an airtight protection against the outside when closed.
During snowy or rainy seasons, a top-sealing damper will prevent any precipitation from sneaking in through the mouth of your chimney. Like any moisture damage, the best way to avoid it is to keep your chimney dry.
If you’re not familiar with the inner workings of your chimney, you may not realize that there’s a flue liner inside the masonry. This chimney liner protects your bricks from everything, like moisture and the corrosive by-products created by combustion.
Older homes sometimes have clay tile liners that have become cracked and damaged over time. Damaged chimney liners allow damaging substances to reach the interior brick, where they can wreak havoc.
An uncapped chimney is like leaving your front door wide open. It exposes your home to the elements and invites unwanted guests in at their leisure. Like a top-sealing damper, a chimney cap prevents rain, snow, debris, and animals from entering your flue through the top of your chimney.
Properly waterproofing your chimney helps reduce the risk of water damage and prevents mold growth. This step should only be taken after the chimney has been inspected and any existing damage has been repaired, as sealing already-damaged brick won’t stop water infiltration.
It’s best to hire a professional for this task, but if you choose to do it yourself, we recommend you to use a polysiloxane-based agent as silicone-based agents tend to trap more moisture.
The National Fire Protection Association (NFPA) recommends having your chimney inspected at least once a year. A professional can accurately identify any existing cracks, determine their severity, and recommend appropriate repairs and preventive solutions to keep your chimney in good condition.
As we already mentioned, you should schedule a professional chimney inspection at least once a year to catch any existing cracks or damage early.
However, if you notice visible cracks, especially large, horizontal, or stair-step cracks, or cracks that are becoming larger and larger over time, you should contact a professional immediately. These could be signs of deeper structural problems that may impact the safety and stability of your home.
Still not sure how to handle a chimney crack? Learn more with the FAQs below.
The cost to repair chimney cracks varies depending on the extent of the damage and the rates of local service providers. Minor repairs may be relatively affordable, while more severe damage can require more extensive and costly work.
Not all chimney cracks are immediately dangerous. Hairline cracks, for example, may not pose an urgent risk. However, more severe types like horizontal or stair-step cracks, or cracks that are growing over time, should be addressed right away to prevent serious structural issues.
If your chimney collapses, follow these steps:
The most effective way to identify existing damage and prevent further issues is by scheduling a professional chimney inspection. If you’re located in Michigan or Ohio, contact Doctor Flue!
We’ve been serving local homeowners since 1986, and our team of fully certified technicians is qualified to accurately assess your chimney and recommend the right solutions.
Give us a call today at (800) 438-3583 or contact us online to request a quote!
Call Us: 1-800-438-3583
Email Us: office@drflue.com
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