Does Snow Cause Damage to Chimneys?
A propane company released a message after 2021’s Winter Storm Uri saying that chimneys and flue pipes should be checked for damage. So, yes is the answer to the question, does snow cause damage to chimneys? Although moisture, in general, is recognized as Enemy Number One to external chimneys, the reason it is so destructive is because of freezing and thawing that occurs in winter. Chimneys can deteriorate and crack because of a buildup of ice and snow. What exactly happens to masonry in freezing weather? Answers follow.
Does Snow Affect Chimney Masonry?
Snow is, of course, an indicator that the weather is below freezing. The temperature itself is what causes damage in masonry that already has water intrusion. Unfortunately, masonry that is free of moisture can end up soaking in water as ice and snow on the chimney and rooftop begin melting. Masonry is porous and highly susceptible to the absorption of water. If temperatures never dropped below 32 degrees Fahrenheit, water inside of bricks may not be such a destructive force. However, in the Houston TX area– a place notorious for summer swelter–below-freezing temperatures happen every year.
The crux of the problem has to do with what happens to the water inside bricks during freezing and thawing cycles. When the water freezes and thaws, it expands and contracts. The movement affects the bricks, resulting in their eventual destruction. When you see a leaning chimney in danger of collapse, it is most likely because:
- Water entered the masonry system;
- Bricks began to deteriorate due to winter weather such as snow; and
- The bricks were never repaired or replaced.
How Else Does Snow Cause Damage to Chimneys?
Bricks are not the only chimney components that can suffer damage due to snow. Chimney crowns and chimney flues are also highly susceptible to the effects of extreme wintry weather.
The chimney crown is the white part of masonry chimneys at the very top. The material chimney crowns are made with is highly susceptible to damage caused by the elements. Checking the chimney crown for cracks is an important part of annual chimney inspections, which all leading fire safety experts in the US recommend.
After severely cold weather such as ice and snow, it is important to check the chimney crown for signs of deterioration. When the chimney crown is damaged, moisture can get into the chimney system between the chimney flue and the chimney’s exterior.
Your chimney flue could suffer damage during harsh winters. Whether because of a chimney leak that caused the flue to deteriorate and crack or because of chimney cap damage, the flue is also vulnerable to snowy conditions.
The best way to ensure that a chimney flue is free of damage is to schedule a Level 2 chimney inspection. During this type of inspection, a special video camera is used to check the walls of the flue liner from top to bottom. Without such equipment, it would be impossible to get a close enough look into the narrow passageway of a chimney.
Call Guardian Chimney Sweep
The expert CSIA-certified chimney sweeps at Guardian Chimney Sweep can help you prepare for winter and repair damage from the effects of freezing temperatures. In Houston TX, rarely is the question “Does snow cause damage to chimneys” relevant. But when it is, you’ll want experienced chimney technicians to handle inspections, repairs, masonry rebuilds, and any further work that is needed. We can also provide a prevention strategy, which involves chimney waterproofing. Contact us online or call Guardian Chimney Sweep today at any of these numbers.
Toll-free: (888) 306-6069
Conroe: (936) 271-9781
Houston: (713) 401-2011