Why Brick Spalls and Crumbles

Spalling is when the face of a brick flakes, pops, or crumbles away, leaving a rough, pitted surface. It’s one of the most common masonry problems in the Quad Cities — and like most brick trouble, it comes down to water and our freeze-thaw winters.

Water gets in, freezes, and pops the face off

Brick is porous — it soaks up water. When that water freezes, it expands about nine percent, and the pressure pushes the face of the brick right off. Repeated through a Quad Cities winter, that’s what turns a solid brick into a crumbling, pitted one. Failing mortar joints and anything that traps moisture in the brick make it happen faster.

What drives spalling

• Failing mortar joints — open joints let water pour into and behind the brick.
• The wrong sealer or paint — a non-breathable coating traps moisture inside the brick, where it freezes and spalls from within.
• Too-hard mortar — modern mortar harder than the brick forces moisture and stress into the brick face instead of the joint.
• Ground contact and splashback — brick that stays wet at the base from soil or splashing spalls first.

Stopping spalling for good

You can’t un-spall a brick — damaged faces are replaced with matching brick. But replacing brick without fixing why it spalled just starts the clock again. The real fix addresses the water: repointing failed mortar, correcting drainage and grading, and using a breathable sealer that lets the wall dry out rather than trapping moisture in. Fix the water, and the new brick lasts.