How to Build a Wood Countertop Out of Plywood

Use a tape measure to determine the dimensions of the entire countertop. Break the system into pieces of countertop that are 8 feet or less in length, which is the length of most plywood sheets.

Measure the desired size of plywood from a 3/4-by-48-by-96 inch sheet and cut it out with a saw. Set this board on top of another plywood sheet or on the leftovers from the first sheet if there are enough and trace the outside to create an identical copy of the first board. Cut out the second board and set the two boards on top of one another.

Sand the edges of the two boards until they are both smooth and identical. Flip the top board upside down and set it next to the bottom board. Choose a board with the best surface as the top board of the countertop. Set that surface facing the ground. Apply wood glue in a light, even layer to the upper surface of the top board then stack the lower board on top of it so they line up perfectly.

Drill holes every 12 inches through the lower board and into the top board, being careful not to drill through to the other side and into the ground. Set 1 1/4-inch wood screws in each hole and tighten them down completely to fasten the boards together. Allow the boards to dry overnight.

Flip the countertop right side up and resand the entire surface of the countertop. Smooth the upper edges and the corners until the countertop is well shaped and smooth to the touch. Leave the bottom edge alone unless a completely rounded countertop is desired.

Wipe the countertop clean and apply the first coat of paint or stain to the wood surface. Use smooth, even brushstrokes and keep it light. Brush along the grain of the wood. Allow the first coat to dry for four hours. Apply two additional coats with the same method or until the finish is the appropriate color or shade.

Apply five coats of polyurethane, following the same method of application as the paint and giving it four hours to dry between each application. Allow the sealant to dry overnight before installing the countertop.

Set the countertop in place in the kitchen. Drill holes upward through the interior of the cabinetry frames and into the countertop. Attach the countertop to the cabinets with appropriately-sized wood screws. Repeat to build the other pieces of countertop you need for your kitchen.