Our Process
How we repair spalled brick in Lock Arbor
How salts inside the brick push the face off
Water moving through masonry carries dissolved salts. When it evaporates at the surface, the salts show as a white bloom that is usually harmless. When the water dries just under the surface instead, the salts crystallize within the brick, and the National Park Service notes that this pressure can make the outer surface spall off.
That is why spalling and moisture go together. Replacing the damaged bricks on a chimney in Lock Arbor is only half the job, and the other half is reducing the water that feeds the salts, which we trace during the free inspection.
Hard mortar next to soft brick
Masonry moves slightly with heat and moisture, and the joints are meant to take that movement. As the National Park Service explains, mortar harder than the brick will not give, so the brick takes the stress instead, and it cracks and spalls in ways that cannot be repaired easily.
An earlier repair made with a hard, cement-rich mortar can be the reason faces break beside the joints. When we see that pattern in Lock Arbor, the estimate says so, and the replacement mortar is chosen to protect the surrounding brick.
Dampening the surrounding brick
Dry brick pulls water out of fresh mortar too quickly, which weakens the bond. Brick industry guidance advises dampening the surrounding brickwork before the new unit is placed, while letting the masonry absorb all surface water so the mortar still bonds well.
It is a small step that is easy to skip on a hot day. Our specialists judge it brick by brick, since sun, shade and the age of the brick all change how thirsty it is. If the wall is soaked from recent rain, we wait for it to dry back instead.
When spalling points to something structural
The Brick Industry Association lists signs that go beyond maintenance: cracks wider than about 0.075 inch, cracks running through several bricks or in a stepped or diagonal line, widespread spalling and masonry that has moved out of plane. It advises that structural issues warrant investigation by a professional engineer.
If we see those signs on a chimney in Lock Arbor, we tell you before replacing any bricks and explain the options, which can include an engineer's review or a partial rebuild. Replacing units one by one on a moving chimney would not last.
