This is an existing wood, bar countertop in a finished basement. The owner was interested in replacing it with a concrete countertop. One of the great things about concrete veneers is that they can go over just about anything, including countertops. So rather than rip out the existing countertop and replace it with a cast-in-place concrete slab, we offered to overlay it. The photo above right shows that sample board we prepared for the customer.
Because the edges of the countertop were slightly modified with 2 x 4's to extend the size of it, we had to do a lot of surface prep. First, we filled in the seams with patching material and levelled the lefthand side of the countertop (photo above left), which was off by about 1/4", and then used another base layer of cement to level the entire surface (above right).
Once the surface was level and smooth, we finished the countertop with a finish layer of cement. The customer had decided on a darker shade of gray, after seeing the sample board above, and to achieve that tone we started with gray portland cement and added some black integral color. The photo above left shows the cement shortly after troweling, and above right, shows the finished countertop after sealing.
The customer wanted a non-gloss, matte finish, so after applying two coats of a water-based epoxy, we applied three coats of a matte wax from Johnson Diversey. This helped greatly in dulling the reflection of the overhead lighting and allowing the true color of the concrete to shine through. One of the unexpected benefits of the dark gray shade chosen by the customer was that it matched the brick foundation of the countertop perfectly.