Each countertop begins with a custom mold that is tailored to your particular project’s specifications. We come to your home or office and make a template from which we construct the mold. The template is made so your countertop will fit exactly in its final location and takes into account any idiosyncracies present, such as walls that are out of square and the like.
Once back in our shop, the mold is constructed from melamine according to the template. We then suspend rebar for strength and stability within the form. The slabs are poured upside down. Therefore any custom details, such as integrated drain boards, sink voids or inlays are attached to the bottom of the form. The entire form is then ready for concrete. The concrete is mixed to ensure that it will be consistently strong throughout the countertop. Micro fibers are added to the mix for strength. The color (if any) is added and the form is filled.
While the concrete is still fresh, the form is vibrated to liquefy the concrete and allow it to flow into every crevice as well as to release any air bubbles have gotten trapped. Unlike standard bagged concrete, the concrete we use for countertop applications hardens very quickly. Therefore, it is closely monitored and hydrated for the rest of the day.
Once the concrete has cured for a 2-3 days, the slab is flipped over (not always an easy process) and the form removed. If you are planning to have aggregate exposed, a rough grinding can be done at this time with 30 or 50 grit. Otherwise the slab is ground down using 100 and 200 grit pads. A slurry of concrete mix is made to fill any small air holes or voids that have occurred during the pour. Then a final grind is done to anywhere from 400-800 grit to polish and hone the finish. The process of finishing can take anywhere from a few days to a week or more.
For the final step, the sealer is applied. There are many types of sealers and each one has its own requirements as far application goes. We will endeavor to choose the one that best fits your situation.
Normally the entire process from making the templates to delivery takes approximately three weeks. Often times one of the tricky things is to find a day that suits both us and our clients for delivery. In certain cases the project length can be much shorter, depending on the complexity of the project. In either case however, the concrete needs to cure properly before delivery is made.