You will need the following tools to build a concrete countertop. These can be purchased in supply stores or home improvement shops.
Required Tools and Materials
Knockouts for sinks
Concrete countertop mix
Wood veneer sheet
Plastic zip ties
Pine 1 x 3s
Medium density fiber board (.0.75 inch thick)
Get a wood veneer. The dimensions should be commensurate to what you need. Trace the countertop base on the wood veneer. The standard overhangs for the countertop is 0.5 to 0.75 inches.
On the template, note the control joints. If the concrete counter is 10’ long, do not allow the control joint distance to go over 4 feet. If you are making longer countertops, you’ll need more control joints.
The general rule when you build a concrete countertop is to distribute the control joints not more than 2 to 3 times the slab thickness. The thickness is in inches.
To build the frame, screw together the 1 x 3s. Use the fiber board for the frame’s bottom. Connect the frame with deck screws. Apply caulk on corners and the inner edges.
Apply paste wax inside the frame. Create a rebar grid with 4 inch intersections. Fasten these with plastic zip ties. Hang the grid by using a couple of 1 x 3s. Place them across the frame. Use a wire to hang it halfway up the frame.
Prepare and mix the concrete. The amount required will depend on the dimensions of your countertop. There are special concrete mixes for countertops available. Depending on the mix, it may be necessary to vibrate the mix. This is to avoid air holes.
When it is finished, get some people to help you put it in place.
Tips and Warnings
Patience is needed when working on this project. Paying attention to detail is very important. You must always wear safety glasses and gloves. At least two individuals will be needed for this task.
Some counters weigh 20 pounds per foot. If the counter is large, several people may be needed to lift it up. The working area must be well ventilated. This is especially true if using gas powered mixers. Good ventilation is very important.
Before you build a concrete countertop, make sure the cabinetry below is capable of supporting the weight. You need to be certain of this so it doesn’t suddenly collapse.