It depends on how deep the spalling goes. If only the very surface has flaked and the brick's core is still intact, it can sometimes be left alone or lightly patched. But once the spalled face has exposed the softer interior of the brick, patching over it won't stop the freeze-thaw cycle that caused the damage, and the brick needs to be cut out and replaced.
Patch materials rarely bond well to a spalled brick face long term. They expand and contract at a different rate than the fired brick around them, so a surface patch tends to crack loose again within a season or two, especially once it goes through another winter of freeze-thaw. That's why a mason will usually recommend replacement rather than patching once the damage goes past cosmetic.
The decision comes down to a few things: how deep the spall is, whether it's one or two bricks or a spreading pattern across a wall face, and whether it's a structural wall or a veneer application. A handful of isolated spalled bricks on an otherwise sound wall is a straightforward spot repair. Widespread spalling across a whole face is a sign the brick itself, or the water source hitting it, needs a closer look.
When Chelo's replaces spalled brick, matching size and color is part of the job, but so is figuring out why that spot spalled in the first place, whether it's a drainage issue, a brick that wasn't rated for the exposure, or a mortar joint that's been letting water in. Cutting out the damaged brick without addressing the cause usually just delays the same repair a few winters down the road.
It also helps to know that spalling and simple weathering aren't the same thing. Weathering is a slow, even softening of the brick face over decades, while spalling is water freezing and forcing a chunk off in a much more concentrated way. A mason walking a wall can usually tell the difference at a glance, which matters because the right fix depends on knowing which one is actually happening.
More on this from Chelo's Brick & Stone.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
