As is commonly known, the basic ingredients of concrete are the combination of water, Portland cement, fine and or coarse aggregates. During the pouring process of concrete, as the aggregates sink and settle, a thin layer of cement paste pushes up to the surface. Within a few hours this top layer is troweled to reach a desired smoothness. Also there can be application of glass, granite, or marble chips added to the top, just below the surface for a specific style.
Simply put, polishing concrete is similar to sanding of hardwood flooring. Heavy-duty polishing machines equipped with progressively finer grits of diamond-impregnated segments or disks that are used to gradually grind down surfaces to the desired degree of shine and smoothness.
Depending on the condition of existing concrete surface and the desired choice of finish. The process begins with the use of coarse metal bonded diamonds or ceramic hybrid matrix. These diamonds are coarse enough to remove minor pits, blemishes or stains, to heavy coatings removal. This preparation process is the most critical for the final smoothing steps. Depending on the condition of the concrete and the desired finish required, the entire process can require from 3-10 steps.
The Three Basic finishes
Cream (industrial look)
Is the term used to describe concrete polishing on the top layer of the cement cream. Generally freshly poured and power troweled concrete floors have a thin layer of cement cream that floats to the top surface while the aggregates sink during the troweling process. This thin layer Is partially grinded along with dirt and whatever other contaminates is present in that particular construction site by our diamond grinding procedure, and then polished to the desired smoothness & sheen for the client. The final “Look” will render a smooth and industrial looking finish with choice of matte, satin, gloss, and mirror finish.
Salt And Pepper
A speckled look can be achieved by grinding slightly below the cream yet before the exposure of the bigger aggregates. Usually one extra metal bonded diamond step required to achieve this look depending on thickness of cement paste. This finish will yield a speckled look from small dots too ¼ inch of aggregate exposure. Again with the Choice of matte, satin, gloss, and mirror finish.
To achieve what we call an exposed finish, this top layer of cement must be removed to give that terrazzo look, Exposing the aggregates requires the removal of the top layer of cream, usually up to 1/2 inch. This finish is the most complex of all the finishes simply because it requires 2-3 additional diamond steps. Furthermore this type of finish requires heavier machines and diamond tooling. Also grouting the surface to fill in pin holes from the extra grinding process will be required to achieve a smoother surface. Pricing for this finish is 25-40% higher than the cream finish. Choice of matte, satin, gloss, and mirror finish are also available.