Why Your Brick Is Flaking and How to Stop It (2024 Guide)

TL;DR: Brick that's flaking or peeling on the surface is called spalling, and it's almost always caused by water getting trapped inside the brick and expanding when it freezes. A brick can absorb its weight in water within hours if it sits against wet mortar or poor drainage, and each freeze-thaw cycle pops a little more of the face off. Fixing the water source stops the damage; replacing individual bricks or repointing mortar restores the wall.

_Last reviewed: July 2026 · 7 min read_

You noticed chips or flakes coming off your brick wall, maybe near the foundation or under a window, and it looks worse every winter. That's not normal aging. It's a sign water is getting into the brick and has nowhere to go.

Okoniq Property Hub keeps a running log of when you first spot exterior damage like spalling, so you can track whether it's spreading season to season instead of guessing.

What Causes Brick to Flake or Spall in the First Place?

Spalling happens when water soaks into brick, then freezes and expands, popping off the outer face in flakes or chunks. Brick itself is porous, capable of absorbing 4-8% of its weight in water depending on the type, and once that water is trapped by a non-breathable seal or dense modern mortar, it has nowhere to escape but out through the surface.

The most common trigger is mortar that's too hard for the brick. Older homes, especially anything built before 1930, used lime-based mortar that's softer than the brick and meant to be the "sacrificial" layer. When that mortar gets repointed with modern Portland cement, which is far harder and less permeable, water gets forced to escape through the brick face instead of the joints. That's when you see flaking concentrated right along mortar lines.

Salt is the other big driver. In colder climates, deicing salt splashed up from sidewalks or driveways gets absorbed into brick near ground level, and salt crystals expanding inside the pores do the same damage as ice, just faster and at lower temperatures. If your flaking is worst in the bottom 2-3 feet of a wall facing a salted walkway, that's your answer.

Is Spalling Brick a Sign of a Bigger Moisture Problem?

Often, yes. Spalling is usually a symptom, not the disease, and the real issue is water reaching the brick that shouldn't be there. Check where your downspouts discharge first. If they're dumping water directly at the base of a wall instead of carrying it several feet away, you're feeding the exact moisture cycle causing the spalling, similar to the pattern covered in 5 signs your downspouts are dumping water in the wrong place.

Grading matters too. If soil slopes toward the foundation instead of away from it, rainwater pools against brick for hours after every storm. A gutter system that overflows or a downspout extension that's missing entirely can double the moisture load on one section of wall, which is why 6 downspout mistakes that send water into your basement is worth checking even if your basement seems fine, since the same water pattern damages brick above grade.

Roof runoff is another overlooked source. A roof shedding more water than it should, whether from missing flashing or worn shingles, can send extra volume down one wall, accelerating spalling in that spot faster than the rest of the house, a pattern similar to what's described in 5 reasons your roof is aging faster than it should.

How Do You Stop Brick From Flaking Further?

Stop the water first, repair the brick second. Fixing spalled brick without addressing the moisture source just buys you a few years before it happens again in the same spot or the one next to it.

| Fix the Water Source | Fix the Brick | |---|---| | Extend downspouts 4-6 ft from foundation | Replace individually spalled bricks | | Regrade soil to slope away from wall | Repoint with lime-based, breathable mortar | | Add gutter guards to stop overflow | Apply a breathable water repellent, not a sealer | | Reduce deicing salt near brick walls | Avoid pressure washing, which drives water in |

The repellent point matters more than people expect. A lot of homeowners try to "fix" flaking brick by sealing it with a film-forming product, which actually traps moisture that's already inside and makes the next freeze cycle worse. You want a vapor-permeable, breathable water repellent labeled specifically for masonry, applied only after the wall has had several dry days.

Can You Repair or Replace Spalled Brick Yourself?

You can handle minor cosmetic flaking, but structural spalling calls for a mason. If only the outer face is chipping and the brick underneath is still solid and square, a breathable repellent and better drainage may be all that's needed. But if bricks are crumbling, crackling apart, or you can push a screwdriver into the face, the brick has lost structural integrity and needs full replacement, not a patch.

Repointing mortar joints is a job most owner-operators can learn for small sections, roughly 10-15 sq ft at a time, using a lime-based mortar mix matched to the original. Anything beyond that, or any spalling near a load-bearing wall or chimney, is worth a mason's eye. Expect $15-$25 per sq ft for professional repointing and $20-$40 per brick for individual replacement, depending on region and brick matching difficulty.

How Much Does Brick Spalling Repair Typically Cost?

Costs range from under $200 for a handful of individually replaced bricks to $3,000-$6,000 for repointing an entire wall face. The wide range comes down to whether you're patching a small area someone caught early, versus a wall that's been spalling unaddressed for 5-10 years and now needs scaffolding and full mortar removal. Catching it in the first year or two of visible flaking is what keeps the bill on the low end.

FAQ

Is flaking brick dangerous or just cosmetic?

It starts cosmetic but becomes structural if ignored. Once spalling progresses past the outer face and starts eating into the brick's core, the wall loses load-bearing strength, especially in load-bearing (not veneer) brick walls.

Can I paint over spalling brick to hide it?

No. Paint seals the surface and traps moisture inside, which accelerates the freeze-thaw cycle and makes spalling worse within one to two winters.

Does spalling only happen in cold climates?

No, though it's most visible there. In hot, wet climates, salt from coastal air or irrigation can cause the same pore-expansion damage without a single freeze.

How do I know if my mortar is too hard for my brick?

If your home was built before 1930 and was repointed with modern gray Portland cement mortar, it's likely too hard. A mason can test hardness, or you can look for flaking concentrated right along the mortar joints as a visual clue.

Will fixing my gutters actually stop the spalling?

In most cases, yes, if gutters and downspouts were the water source. Spalling that's already happened won't reverse itself, but stopping the water supply prevents it from spreading to new bricks.

This is educational information, not engineering or structural advice. Call a licensed mason or structural engineer if you see cracking, bulging, or spalling near a load-bearing wall or chimney.