Understanding Concrete

Below are detailed descriptions on the four levels of concrete polishing along with the aggregate exposure, which dictate the appearance of the finished product.¹

Concrete Gloss Levels

Level 1 - Flat

Level 2 - Satin

Level 3 - Gloss

Level 4 - High Gloss

Grit: <100

Sheen Level: Ground

Abrasive Passes: 4

Gloss Reading: N/A

Grit: 100-400

Sheen Level: Honed

Abrasive Passes: 5

Gloss Reading: 40-50

Grit: 400-800

Sheen Level: Polished

Abrasive Passes: 6

Gloss Reading: 50-60

Grit: >800

Sheen Level: Highly Polished

Abrasive Passes: 7

Gloss Reading: 60-80

A level 1 ground polish is traditionally obtained by stopping below the 100-grit resin bond. It will appear somewhat hazy with little, if any, clarity or reflection when looking directly down at the floor.
A level 2 honed polish is obtained by stopping at the 400-grit resin bond, producing a low-sheen finish. When looking directly down at the finished floor and at a distance of roughly 100 feet, a slight overhead reflection is visible. This grit level produces a low-luster matte finish.
A level 3 polish is accomplished by using up to an 800-grit or higher diamond abrasive. The surface will have a much higher sheen than that of the level 2 finish, and will produce greater light-reflectivity. At a distance of 30 to 50 feet, the floor will clearly reflect side and overhead lighting.
This level of polish produces a high degree of shine, so that when standing directly over the surface, one can see their reflection with total clarity. A level 4 polish is obtained by using up to a 3,000-grit resin-bond diamond or by burnishing the floor with a high-speed burnisher.

Aggregate Exposure Classes

Class A - Cream

Class B - Salt & Pepper

Class C - Medium

Class D - Large

Approx. Surface Cut Depth: < 1/16 in

Approx. Surface Cut Depth: 1/16 in

Approx. Surface Cut Depth: 1/8 in

Approx. Surface Cut Depth: 1/4 in

Class A provides very little aggregate exposure, with a generally uniform appearance.

Class B provides fine aggregate exposure, with a salt-and-pepper-like appearance. There may be some small or medium aggregate at random locations.

Class C provides medium-sized aggregate exposure, with a chance of some larger aggregates at random locations.

Class D provides large, coarse aggregates throughout the space, with little to no fine aggregates at random locations.

¹ The information provided on this page has been aggregated from the Concrete Polishing Association of America