Key takeaways
- Spalling comes from water, frost and trapped moisture
- Hard mortar and coatings can make it worse
- Fix the water source first
- Replace badly damaged bricks with matching units
What spalling is
Spalling is when the face of a brick flakes, peels or pops off. It happens when water gets into the brick and freezes, expanding and breaking the surface apart, or when salts crystallize inside the brick.
A little spalling on a few bricks is common on older walls. Widespread spalling points to a moisture problem that needs to be found.
Common causes
Mortar that is harder than the brick pushes stress onto the brick instead of the joint. Sealers and paints that trap water inside the brick can have the same effect. Missing flashing, leaking gutters and ground that slopes toward the wall keep a wall wet.
Soft or underfired brick may be more prone to spalling than a harder, well-fired brick.
What fixes it
Fix the water first: gutters, flashing, grade and failed mortar. Then replace badly damaged bricks with matching units, and use a mortar that is softer than the brick.
Do not paint or seal over spalling brick. Trapped moisture usually makes things worse.
Related services
Quick answers
Can spalled brick be repaired without replacing it?
Light surface flaking can sometimes be left alone if the water problem is fixed. Deeply spalled bricks are usually cut out and replaced.
Will sealing spalled brick stop the damage?
Usually not, and a film-forming sealer can make it worse. Fixing the water source and using a breathable repellent in the right case is the safer path.
Ready to talk it through? Get a free estimate or call 615-431-3789.