In concrete, spalls are usually caused by corroding reinforcing steel swelling as it rusts and pushing the cover off. In masonry, freeze-thaw cycling of saturated units, salts and hard mortar that will not give cause the face to pop off. Spalling is both a leak symptom and a falling hazard, so facade inspections map and tag every loose piece.
Balcony edge is spalling, rebar's showing, sound it with a hammer and tag everything loose before we drop.
Sounding with a hammer finds hollow, loose concrete long before it falls; a dull thud marks the spot.
Also heard as
- spall
- spalled concrete
Related terms
Efflorescence
White crystalline salt deposits left on masonry or concrete as water moving through it evaporates.
Repointing
Raking out deteriorated mortar joints in masonry and refilling them with new mortar.
Dutchman
A patch of new stone, brick or wood cut and set into a damaged area of an original piece.
Substrate failure
The joint face itself breaking, so sealant comes away with a skin of concrete, coating or EIFS still attached.
Same word, different worlds
Flaking of large chunks from a bearing race or gear tooth after fatigue cracks below the surface link up.
Thermal SprayFlakes or chunks of coating breaking away from the surface, typically under thermal cycling or impact.
Refractories & Furnace LiningsCracking off of pieces or layers from the hot face of a refractory lining.
Gear EngineeringLarge, irregular flakes broken out of a tooth surface, usually where pits have grown and joined.
Concrete & CementChunks or flakes breaking away from a concrete surface or edge, often from corroding rebar beneath.