What does parging actually protect on a foundation wall?

Parging protects the exposed, above-grade part of a foundation wall. It is a thin cement or acrylic coat over concrete or block that sheds rain and splash, slows salt and freeze-thaw damage, and gives the base of the house a clean, finished look. Bare concrete and block absorb water, and in Ottawa that water freezes and expands in the surface every winter, which slowly breaks the face of the wall down. A sound parge coat takes that wear instead, so it is the coat that gets repaired rather than the foundation itself. Parging does not waterproof the wall below grade and does not fix structural cracks. For a fuller explanation, see our guide to what parging is.