What we call polished concrete is the slab’s own surface, ground, honed and polished in stages with finer and finer diamonds until it is smooth and reflective. A liquid densifier hardens the top, and a guard or stain protector may be the final coat. Epoxy, polyaspartic and urethane floors are different: they are films laid over the slab.
Grit steps
Work starts with coarse diamonds in a metal bond that cut the surface and remove old coverings. Finer resin-bond diamonds follow, and each step removes the scratches of the one before. More steps and finer tooling mean a more reflective floor.
Gloss levels
A manufacturer guide that reproduces the Concrete Polishing Council’s levels lists four: 1 flat (ground), 2 satin (honed), 3 polished and 4 high polish. Honed is the matte-to-satin stage. How shiny a floor is does not tell you how grippy it is, so choose the finish for the use as well as the look.
Cream, salt-and-pepper or aggregate
On the council’s chart the look depends on how much of the slab’s stone shows. Cream is mainly cement paste with a little fine sand, salt-and-pepper shows fine aggregate and full aggregate exposes the coarse stone. The result comes from the mix and from how the slab was placed and finished, which is why we agree a test area before the whole floor.