Exposed aggregate
A finish in which the surface mortar is removed to reveal the decorative stone beneath, producing a durable, slip-resistant, naturally textured surface.
What does exposed aggregate mean?
Exposure is achieved by washing and brushing the surface at the right moment, by applying a surface retarder that delays set in the top layer, or by abrading the hardened surface. Because the aggregate itself becomes the finish, stone selection is a design decision. The resulting texture is highly slip resistant and hides wear well, which is why it endures on walkways and pool decks.
In practice
The pebbly sidewalk and pool deck finish common across the Sun Belt is exposed aggregate, and it is achieved by washing rather than by adding anything.