Etched/Grind Finished Concrete



Description:
2500 PSI - 1" Minus Rock
3.5" to 4" Thick

Process:
Etched:
Etched finish concrete is set up and poured similar to broomed or salted finishes. It too uses the integral coloring system if a color is desired. The concrete is poured, troweled smooth and is left to cure over night. The following day we return to the job and use one of two ways to etch concrete (Buff wash or Sandblasting.) Buff wash is the preferred way to etch concrete. An acid base solution along with water is applied to the top of the day old concrete. The acid solution is scrubbed into the concrete with brushes to expose some of the aggregate fragments in the concrete and then rinsed off with water.

The other way to etch concrete is by sandblasting the concrete. It is preferred to return to the job the following day to sandblast the concrete while it is still somewhat soft (same as acid wash).
It is possible to have the concrete sit for more than one day; however, the longer one waits to etch concrete, the more it will have time to cure and the more difficult it will be to etch. There is very
little difference in look from the buff wash and the sandblasting processes.

A third way to etch concrete is with the use of specially designed retardants that allow the concrete to be etched to varing depths, depending on the desires of the client. This process begins on the day the concrete is poured. Just before the final stages of the troweling process, the chosen retardant is applied to the area. The next day the retardant is removed either via pressure washing or with a buffing machine. The specially designed retardants can achieve etched to heavy exposed ranging in depths of sand finish to 1" to 1-1/2".

When etching concrete the top layer is essentially removed to reveal the fragments of aggregate and the color can become lighter than it would have been if the concrete was not etched. It is recommended that etched concrete be sealed. The type of sealer has a great effect on the intensity of color you see. A high gloss "wet look" sealer will bring out the color to its brightest/deepest color. A penetrating sealer is the most mundane of our sealers and the color appears as if there were no seal even applied; thus, the concrete will appear lighter in color.

Grinding/Honing/Polishing:
Grinding is a method used to achieve a finished look similar to the sand and etched finish but with a smoother surface. For a grind finish, a heavy grit is used in conjunction with a grinding machine that removes the top layer of concrete to expose the sand and aggregate below. But since the process involves using a diamond grit material, the finish becomes smoother to the touch, but still allows good traction. To achieve a honed or polished concrete you increase the grit and sand away the concrete until the final look is reached. A polished concrete will finish with a 3000 grit and have a more mirror reflective finish. The polished concrete is recommended only for interior concrete floors due to the slip factor rises as the finsih of the floor is grinded to higher grit finishes. The following images are a exposed truck aggregate with a heavy exposure and then grinded down to a 100 grit. The second photo is a polished concrete grinded to a 3000 Grit showing the reflective propoerties of polished concrete. And the third image is a hand-seeded blue glass with a 3000 grit polished finish.







Curing Period:
We recommend that the concrete sit for a few days before any foot traffic be applied. We suggest that no vehicles or heavy items be placed on the concrete for at least 28 days, after which the concrete will be fully cured. If 28 days is not feasible to stay off the concrete, the psi (the density
of concrete) can be increased so that the concrete will cure faster and will be able to withstand
the weight of a heavy item such as a vehicle in less time.