Learning how to make kitchen concrete countertops requires some patience and skill. A concrete counter is less expensive than granite, and can give your kitchen a modern look, but a lot of care needs to go into producing it.
Forming the Concrete Counter
Concrete countertops are made in a similar fashion to any concrete form, such as sidewalk slabs or steps. The main difference is the type of concrete used; to give the countertop strength a very dry mixture of concrete is used. This dry concrete will not self level; you will need to tamp it down yourself with some elbow grease to get your counter level.
Before beginning your countertop project, you may want to build one or two smaller molds and produce a few samples to perfect your technique before moving on to the larger project. To make a concrete counter, you will need the following:
- 3/4 inch thick melamine particle board
- Plywood block outs for sinks and faucets
- Silicone caulk
- Steel mesh
- Concrete mixture of one part cement, two parts 3/8 inch pea gravel, three parts sand, water, water reducer and pigment
- Magnesium float
- 2 x 4 cut longer than the width of the counter
- Pry bar
- Power sander
Making Kitchen Concrete Countertops
While you can build your concrete counter right on top of your cabinets, you may have an easier time creating your counter in a garage or open area and transferring it to the cabinets once it's cured.
- Measure the current countertop and use these measurements to build your mold.
- Use 3/4 inch thick melamine coated particle board to form the bottom, sides and end of the mold. Screw the pieces of melamine together and seal any seams or edges with silicone caulk to create a watertight mold.
- Smooth out the silicone with your finger to get it as neat as possible; the silicone can mark the concrete so take care with this step.
- Create block outs from plywood in the shape and size of your kitchen sink faucets and place them in the mold in the correct areas.
- Mix up your concrete until it is moldable and oozes but does not pour from your fingers.
- Carefully pour the concrete into the mold, evenly distributing it through the mold and around the knock outs.
- Tamp down the concrete with the magnesium float, vibrating it so any trapped air bubbles come to the surface of the concrete. If depressions occur, add more concrete to those areas. Take the time to ensure the concrete moves evenly into the corners and around the knock outs.
- Place a 2 x 4 on the surface of the concrete and saw it back and forth as you move it along the length of the counter. This will remove excess concrete from the mold, pushing it down the length of the counter and off the edge. Repeat several times until the concrete is level.
- Trim the steel mesh so that it comes within one inch of the sides of the mold. Place it on top of the concrete and push it down into the counter so it floats in the center. Do not push until it reaches the bottom of the mold.
- Smooth and level the top of the counter with the float.
- Allow the concrete to dry for two to four days at a temperature between 70 and 80 degrees.
- Carefully pry off the sides of the mold and get help to gently turn the concrete slab over. Remove the melamine from the top of the slab to reveal the surface of your counter.
- Sand down the top and edge of the counter with 100 grit sandpaper to deepen the color and remove any rough spots. Wait until the counter is in place to break up and remove the knock outs for the sink and faucet.
- Attach the counter to the cabinets with silicone caulk adhesive, gently lowering it into place.
- Seal the concrete with a water based sealer and a brush to help protect it from stains.
- Practice Makes Perfect
Working with concrete that is drier in consistency can take some time to get right. Build two or three smaller molds and work on the consistency and color of the concrete as well as the tamping and leveling process until you are satisfied. Learning how to make kitchen concrete countertops can be considered an art form; minor imperfections can help lend character and interest to the finished product. Take your time with each step, contact your local concrete dealer at any time with questions and know that you will produce a kitchen counter worthy of any show place.