Chimney Brick Spalling: What it Is & What to Do About It

A variety of things can affect the condition of your chimney’s bricks and mortar and cause the chimney to be unsafe. A common problem we find during chimney inspections is brick spalling. Left unattended, spalling bricks can lead to expensive and complicated repairs. If caught early, solutions are fairly straightforward.

What is brick spalling?

Spalling is the term used to describe bricks that have begun to crumble and dislodge. Damage to the exterior brick surface is usually the first sign.

What causes spalling bricks?

Chimney Brick Repair In Atlanta, GABrick damage can be caused by several things:

Inferior mortar: Cheap or incorrectly applied mortar used to build the chimney can “squeeze” the bricks during freeze/thaw cycles and cause cracking.

Old age: Very old bricks are prone to spalling after years of wear and weakening.

Issues with the house: Normal house-settling as well as settling due to a structural problem with the brick walls of the home can lead to spalling.

Salvaged bricks: Re-used bricks are more prone to damage than new, high-quality bricks.

Badly constructed chimney: If the chimney is poorly constructed, the bricks and mortar may not hold up to the effects of freeze/thaw cycles.

Other factors can contribute to spalling bricks. A certified chimney inspection is the only sure way to learn what’s causing the problem.

The result of loose and damaged bricks

A big concern for chimney sweeps when looking at a damaged chimney is ongoing water infiltration. The more water that can get into the bricks and mortar, the more damage you can expect down the line.

Leaky chimneys can allow water to run into the flue and begin a cycle of internal decay. Compromised bricks trap and hold moisture, which easily can lead to the growth of dangerous mold, mildew and bacteria.

Additionally, a significant chimney leak can cause water to spread to vulnerable areas of the home and result in rotting and decay to wall boards, insulation, ceilings and more.

Finally, if left unattended, spalling bricks can cause a chimney to begin to lean to one side and eventually collapse.

How to spot signs of brick and water damage to your chimney

It’s a good idea to periodically look over your chimney structure to check for spalling bricks. In some cases, signs of water infiltration are easier to spot than brick damage.

Look for these signs of a leaky chimney:


  • Water in the firebox
  • Rusted damper
  • White staining (efflorescence) on the exterior masonry
  • Dampness on walls and the ceiling adjacent to the chimney
  • Strong musty odors coming from the fireplace

Chimney Masonry repair in Marietta, GASpalling repair

After a certified inspection of your chimney, the technician will understand the extent of the brick-spalling problem and know the best way to remedy the situation.

For minor brick/mortar damage, a waterproof sealant can be applied to prevent more water from getting into the cracked areas. This won’t fix existing brick damage, but it will keep water out of the system.

A process called tuckpointing often is useful in repairing chimneys where sections of bricks and mortar are missing. This chimney repair work involves adding new, strong mortar to open areas to restore structural soundness to the chimney. If considerable masonry damage exists, it may be necessary to rebuild parts of the chimney or the entire structure. In these cases, chimney service professionals may recommend a more extensive chimney inspection to understand the extent of the damage to the masonry and the home itself.

If your chimney has spalling bricks, call Chimney Solutions of Alpharetta, GA, right away. We’ll inspect your chimney and help you get the problem resolved quickly and correctly. Call (770) 771-5501 today.


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