As concrete countertops become more popular for kitchens, bathrooms, and other work areas, the prices of the professional labour to obtain them go up. Unfortunately, this is the rule of supply and demand. What the professionals do not want you to know is that you can build a concrete counter yourself without as much trouble as you might imagine. Getting that shiny, polished showroom finish is possible with the right amount of patience.
- Skill level:
Things you need
- Fibre-free concrete
- Reinforced concrete
- Plastic tarps
- Coated particleboard, pieces long enough to build a frame for your countertop
- Electric screwdriver
- Drywall screws
- Metal finishing trowel
- Magnesium float
- Wire snips
- Diamond lath metal mesh
- Metal channel screed
- Safety goggles
- Work gloves
- Paper mask or respirator
- Orbital sander and 100-grit discs
- 1 qt. muriatic acid
- Paintbrushes or paint rollers
- Garden hose
- Rubber grout float
- Concrete filler
- Construction adhesive
- Fine-grade scouring pad
- Acrylic clean finish
- Paint pan
Decide how long and wide you want your countertop to be. Multiple these numbers together. Also multiply the length and width of each counter edge and add these to the first number. Determine how thick the finished countertop should be. Multiply the total surface dimension by this number. The result is the total area of the countertop you will build.
Purchase enough of the fibre-free and reinforced concretes to cover your countertop area; check the packaging to find out how much area one container covers. Have the store mix both of your concretes to save yourself the trouble.
Cover your lawn or patio with a tarp to protect it. Build a frame on the tarp with an enclosed bottom that matches your countertop measurements, using the lengths of coated particleboard, an electric screwdriver and drywall screws.
Gather some fibre-free concrete onto a metal trowel. Apply an even 1-inch layer to bottom and all of the sides of your frame. Pour reinforced concrete into the frame until it is approximately 3/4 of the way full. Use a magnesium float to smooth the surface of the concrete and pack it down a bit. Move the float in sweeping arch motions when smoothing the surface.
Use the wire snips to cut a piece of diamond lath metal mesh to fit on the surface of your countertop, leaving 1 inch of concrete uncovered on all sides. If the mesh is too close to the edges, it will weaken them. Drop the mesh into place, as close to the approximate centre as possible. Get someone to help you, if necessary, to place the mesh appropriately.
Fill the other 1/4 of the frame with the fibre-free concrete. Pack down the concrete and smooth the surface with the float.
Drag a metal channel screed from one end of the frame to the other. Use a sawing back-and-forth motion to level the surface of the countertop. Allow the concrete to cure for two hours.
With a metal finishing trowel, use the same large, arching motions that you used with the float to perform one final finishing of the concrete. Allow the finished countertop to cure for at least 48 hours. Remove the screws from your frame, using an electric screwdriver, and remove the frame from your countertop.
Put on safety goggles, work gloves, and a paper mask or respirator. Identify any rough or thick areas of concrete. Sand them with an orbital sander loaded with a 100-grit disc until the countertop is smooth and level everywhere.
In a large bucket, mix together 29.6ml of muriatic acid for every gallon of water needed to cover your countertop. Use a paintbrush or paint roller to apply this solution to the countertop. Wait five minutes, then use a garden hose to rinse the countertop completely.
Use a rubber grout float to apply the concrete filler, following the product directions. Let the filler dry for one hour.
Place a new 100-grit disc onto your orbital sander and sand the entire countertop in long, even lines. Begin at one end and work toward the other, remembering to sand the edges. Clean away any dust or debris that clings to your countertop after the final sanding.
Apply a thin bead of construction adhesive around the top edges of your base cabinets, using a caulk gun. Recruit several people to help you lift the heavy countertop and set it carefully into place atop the construction adhesive.
Scour the entire surface of the countertop, using a fine-grade scouring pad and moving in circular motions. Do not forget the edges.
Pour the acrylic clear finish into a plastic paint pan. Apply a thin, even coat to the countertop, using a paintbrush or a paint roller. Allow the finished countertop to dry overnight.