Brick pops or appears to explode in winter when water that has soaked into the brick freezes and expands with enough force to blow a chunk off the face. It typically happens right after a stretch of rain or snowmelt is followed by a hard, fast freeze, so the water inside the brick has no time to dry out before it turns to ice and expands.
Brick is porous, water works its way in through capillary action whenever the surface is wet. Once that water is trapped and the temperature drops, it expands as it turns to ice. That expansion pushes outward against the brick from the inside, and if the pressure exceeds what the brick's face can hold, a piece of it breaks off, sometimes with an audible crack or pop during a hard freeze overnight.
Not all brick is equally vulnerable. Brick that was never rated for heavy weather exposure, brick that's already old and softened, or brick that's sealed with a coating that traps moisture instead of letting it breathe are all more likely to fail this way. The Blue Ridge foothills go through this saturate-then-freeze cycle repeatedly across a winter, which is why the damage tends to show up on the same faces year after year if the underlying cause isn't fixed.
When Chelo's looks at a case of popped brick, the first question isn't just which bricks to replace, it's where the water is getting in and staying in. That might mean checking the mortar joints, the flashing above the area, or the grade around the foundation, because replacing the brick without addressing the water source usually means it happens again the next hard freeze.
It's also worth noting that popping isn't limited to the coldest part of winter. It tends to show up right after a swing from wet weather into a sharp overnight freeze, which can happen as early as late fall or as late as a cold snap in early spring across the Carroll County area. Homeowners often notice it as debris or brick fragments on the ground below a wall after a hard freeze, well before they'd think to inspect the wall itself.
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.
