Determine the shape and dimensions of your concrete tabletop. You can create a basic design in just about any shape you desire, from a simple square or rectangular design to an oval or circular shape. The tabletop should be at least 2 inches thick. Calculate the dimensions so you know how much concrete you need for the job.
Purchase the concrete mix and rent a mixer. Both these tasks can be accomplished at many home supply stores as well as at farmer’s exchanges and building supply stores. Take along your measurements; the store associates can assist you in selecting the right concrete mix and making arrangements to deliver the mixer.
Acquire your other supplies. To provide strength to your concrete tabletop, purchase steel mesh, known as remesh, as well as long thin steel bars called rebar. Using both of these elements in the tabletop will make it much more stable and easier to move without breaking.
Create your mold. This can be accomplished by building a simple mold out of wood. Make sure the mold is at least 3 inches deep, or 1 inch deeper than the thickness of your tabletop.
Mix the cement, following the product instructions, in the mixer just before you are ready to pour the tabletop. It is important to introduce the concrete into the mold before it begins to harden. Position the steel mesh in the bottom of the mold. The mesh will help to add support to the underside of your tabletop.
Pour in half of the cement and allow it to settle. Use the trowel to smooth out the surface. The cement should completely cover the steel mesh and be more or less an even depth throughout the mold.
Place the rebar into the mold. Ideally, place a bar near the edge of each side of the tabletop, plus two more in the body of the top. The rebar reinforces the overall strength of the tabletop.
Pour the remaining cement into the mold. Smooth the surface with a trowel. Allow the cement to dry in the mold according to package instructions. This process may take several days, depending on the size of the tabletop.
Disassemble the wooden mold to reveal the completed tabletop. Once the top is free from the mold, use a grinder to smooth the surface. Follow up with a polishing agent to seal the surface of the concrete and protect the tabletop from moisture and other elements that can damage the surface.