Spalling: How Cold Winter Temperatures Affect Your Chimney

Chimney Spaling Damage - Atlanta GA - Old Hat Chimney ServiceOver time, the exterior bricks and mortar of your masonry chimney are going to naturally suffer weather-related damage no matter how well-built your chimney may be. Not only do older chimneys experience deterioration, newer masonry chimneys can also show signs of damage if they are not properly maintained. The biggest signs of masonry decay include cracks, holes, and broken bricks and mortar, All of these signs are symptoms of spalling, a term we at Old Hat Chimney Service often have to explain to customers. We would like to take an opportunity to tell you more about the causes, impact, and repair of chimney spalling damage and how cold winters lead to spalling.

What exactly is spalling?

Spalling is the chipping off or loss of surface of any masonry material, including a brick chimney, a masonry block chimney, or even concrete sidewalks. You are most likely with how potholes appear on roads after a snow or ice storm; that is a perfect example of spalling damage.

What causes spalling?

The biggest enemies of a masonry chimney are water exposure and penetration, and these things have a lot to do with spalling. With the most severe damage occurring in colder climates, the freeze-thaw process causes major spalling deterioration. When water leaks into the bricks and mortar of your chimney, that trapped water will freeze in cold temperatures and expand. As the temperatures rise and the ice thaws, parts of those bricks and mortar will break off completely because of the stress of the expansion. Each time this cycle repeats in a season, the more spalling occurs, and eventually, structural damage to your chimney can result.

Other than structural damage, are there other impacts of chimney spalling?

Yes, besides structural damage to your chimney, spalling can cause bricks to fall into your chimney and cause a hazardous flue blockage. Your flue should always be inspected when your chimney suffers from spalling damage. Additionally, holes left in your chimney structure from lost bricks and mortar increase the opportunity for more water leaks, which leads to more costly damages.

How can spalling be repaired?

If the damage is not too serious, the expert masons at Old Hat Chimney Service can fill in the holes, brick by brick. In the worst case scenario such as your chimney suffering severe spalling damage, we will need to tear it down to a sound level and rebuild. When a flue has also suffered damage, rebuilding the chimney allows for new flue tiles to be installed.

How can I prevent spalling? 

Keeping water out is the main key to prevent spalling damage. To stop water leaks, you should be sure you do not have a damaged or missing chimney crown or chimney cap. Damaged flashing also leads to water penetration of your masonry chimney. Our certified technicians at Old Hat Chimney Service can inspect, repair, and install all three of these essential components of your chimney. We can also apply a 100% vapor-permeable waterproofing formula to further protect your masonry from water-caused spalling damage.

If you have noticed signs of spalling on your chimney, contact Old Hat Chimney Service today. Our masons will take care of your chimney and give their full attention to any damage done.