Polished Concrete v’s Grind & Seal

Mechanically Polished Concrete Process

A mechanically polished concrete floor is very time consuming if done correctly, this is due to the fact that there are at least 10 – 15 steps involved. The general rule is to start the initial grinding with a coarse 16 – 30 grit diamond and grind to the desired aggregate exposure level desired and finish with a 1500 – or 3000 grit diamond, depending on the gloss level required. These diamonds are impregnated inside a metal or resin bonded segment. Typically the diamonds grit size will double once the first grind has been carried out. The use of 16 or 30 grit size diamonds, then use 60/80 grit diamonds followed by the 120 grit metal bond diamond segments. The polishing process begins with a 50 grit diamond resin pad instead of a metal segment. When using the resin pads the steps may be 100, then 200, 400, 800, 1500 and finally 3000 grit. Throughout the process a densifier is used to harden the concrete surface, which allows the concrete to be polished. A number densifiers can be used; these consist of a lithium, potassium sodium silicates. A grouting chemical is also used throughout the process to fill in any holes, cracks or imperfections that were exposed from the initial coarse grinding step. The concrete is then sealed with a natural-look impregnating sealer: this sealer penetrates 2-5 mm inside the pores of the concrete preventing any deep staining from oils and spills.

Grind and seal Polished Concrete Process

This system is the standard polished concrete system where the concrete surface is ground to the aggregate level desired using coarse 16- or 30- grit metal-bonded diamonds. When the desired grind level is achieved, the surface is re-ground with usually a 60- grit to remove any visible scratching the followed by 120 grit. Grouting and patching may be required to fill any voids, holes cracks or imperfections. The surface is then cleaned and prepared for the application of either a gloss or matte surface coating.