Spalling
Flaking, chipping or delamination of a concrete or masonry surface, usually driven by freeze-thaw cycling or corroding embedded steel.
What is Spalling?
Water absorbed into concrete or brick expands when it freezes and breaks the surface apart over repeated cycles. Where reinforcing steel is embedded, corrosion of the steel expands it and pushes the surface off, which is why spalling on a balcony, parking deck or lintel is treated more seriously than surface spalling on a step — it can indicate section loss in structural steel. Inspectors report location, extent, and whether reinforcement is exposed, and refer structural cases for engineering evaluation. On chimneys, spalling frequently accompanies a missing or cracked crown.