As your well-built masonry chimney ages, your exterior bricks and mortar are going to naturally suffer weather-related damage. Not only do older chimneys experience deterioration, newer masonry chimneys can also show signs of damage if they are not properly maintained. Unfortunately, the decaying of chimney masonry is a slow, gradual process and not always easy to spot. The biggest signs of masonry decay include cracks, holes, and broken brick and mortar. All of these signs are symptoms of spalling. We would like to take an opportunity to tell you more about the causes, impact, and repair of chimney spalling damage and how the freezing temperatures of winter lead to spalling.

Winter Chimney Problems - Portland OR

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.

What causes spalling?

Water exposure and penetration, the biggest enemies of your masonry chimney, 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 brick 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 brick 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 brickwork 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 brick and mortar increase the opportunity for more water penetration, which leads to more costly damages.

How can spalling be repaired?

If the damage is not too serious, the expert masons at American Chimney & Masonry can fill in the holes, brick by brick. In the worst case scenario, if your chimney has undergone severe spalling damage, we will need to tear it down to a sound level and rebuild your chimney. 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 essential 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 American Chimney & Masonry 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 American Chimney & Masonry today. Our masons will take care of your chimney and give their full attention to every damaged brick.