A concrete countertop is easier to create than you think. If you can mix and pour concrete, then you can easily create your own pour in place or moving concrete countertops. All you need are a few basic tools, a bit of plywood and some concrete to get started. Use the following guide and tips to help you get going in the right direction for the perfect concrete countertop for your kitchen, bathroom or any room in the house.
The easiest way to create a perfectly sculpted concrete countertop is by creating a perfectly sculpted form. The form that holds the concrete in place not only keeps it where it’s supposed to be while it’s wet, but it also shapes the concrete as well, and any imperfections in the form will result in an imperfection in the concrete.
For pour in place slabs, a single piece of ½-inch Medium Density Fiber (MDF) Board will do the trick for the main section of the slab. Install the MDF board in your vanity base so that the form fits flush with the top of the vanity. For the bullnose or square edge (the part of the countertops that overhangs the vanity and will be an exposed edge) you’ll need to use a piece of laminated MDF board. It’s used to create as smooth as surface as possible and to keep the form from sticking to the concrete after it has dried. This form should be built separately and should be supported from underneath with temporary 2×4 supports until the concrete has cured completely.
For concrete countertops that you plan on lifting into place, be sure to use an all laminate MDF board to prevent the form from sticking to the concrete during the curing process.
Seal all form seams with latex caulk. This will prevent any water or wet concrete from seeping through the small gaps in the form and flowing into the cabinets underneath.
Mix the concrete heavy-to the consistency of dough so that it does not flow. The stiff mud is then pressed into the form, not poured. If the concrete is too wet, it will end up on the floor instead of in the form. Quickly place the concrete into the form as time is of the essence with stiff mud. You may need to use a curing retardant for larger concrete countertops that may take some time to fill. Don’t forget to add in a few pieces of steel rebar or mesh for support-especially around thin sections of the concrete countertop.
Use a simple concrete trowel to smooth out any inconsistencies into the surface. You may need to splash a little water onto the surface of the concrete to help raise the slurry and create a smoother finish. Once it’s as smooth as it’s going to get, let it dry overnight before seasoning the surface of the concrete countertop with a nontoxic finish such as linseed oil or mineral oil.