Concrete problems and how to fix them
What causes each failure, whether it is structural or cosmetic, how it is repaired and how it is avoided next time. Most concrete defects come from finishing, curing, or water under the slab rather than from the mix.
Concrete scaling
The surface flakes off in thin patches, typically a sixteenth to a quarter inch deep, exposing the aggregate underneath. It usuall…
CosmeticConcrete dusting
A fine powder comes off the surface under foot traffic or when wiped with a hand. The slab looks sound but never stops shedding, a…
May be structuralConcrete spalling
Chunks break away from the surface, deeper than scaling — often a half inch or more — sometimes exposing reinforcing steel. Rust s…
CosmeticEfflorescence on concrete
A white, chalky or crystalline deposit on the surface, often appearing after rain or in the first months of a slab's life. It can …
CosmeticConcrete crazing
A network of fine, shallow cracks across the surface, often described as looking like a dried lake bed or cracked glaze. Individua…
CosmeticConcrete curling
Slab edges and corners lift off the base, most obvious at joints where two panels no longer meet flush. Under wheel traffic a curl…
CosmeticSinking or settling concrete
A slab section sits lower than its neighbours, creating a lip at the joint. Common on driveways near the garage apron, on walkways…
CosmeticConcrete discoloration
Blotchy dark and light patches across a slab that should be one tone, or a distinct colour difference between areas placed from di…