A perfect polished concrete floor

GRINDING.

Grinding (also called honing) is the first step, where the surface is mechanically removed. This step is normally done 10 – 20 days after the concrete is laid but can be done at any time on older existing concrete. This process exposes the aggregate (stones) in the concrete, although it is possible to polish the surface without revealing any aggregate. The standard concrete aggregate can be supplemented with other materials such as glass and shell when it is being laid, which are then revealed with grinding. The deeper the grind, the more aggregate is visible. The depths of grinding are described as follows:

• Natural Polish – 0 mm of the surface removed
• Salt and Pepper grind – 1-2 mm of the surface removed
• Light grind – 2-3 mm of the surface removed
• Medium grind – 3-4 mm of the surface removed
• Heavy grind – 5+ mm of the surface removed

POLISHING.

The second step is the polishing of the concrete, where the surface is made smoother by passing over the floor multiple times with increasingly finer pads. If you think of different grades of sandpaper, you start with the rough and work your way to a smoother grade to finish. With polishing, 100 grit gives a rough floor, and you can go up to 3,000 grit which gives a mirror finish.

While a floor that has simply been ground can be sealed, a true polished floor is treated with a densifier which hardens the concrete, then a microfilm is burnished into the surface after polishing.

Honing or grinding your floor will create the finished look, so there are some important things you need to consider:

Aggregate colour.

Check with local concrete mix companies to see what stone is available – the dominant colour is usually the colour of the stone (except for the salt and pepper grind).

Concrete colour.

Use one of our colours to set the tone.

Aggregate shape.

Angular or round pebbles are popular choices.

Depth of honing.

Level of honing (smoothness).

100 grit (rough) – 3,000 grit (mirror finish).