DIY Plywood Backer Board Countertops

Measure the dimensions (length and width) of the cabinet top with a measuring tape. Double-check the measurements to ensure they are accurate.

Measure and mark the cabinet top's dimensions on a sheet of 3/4-inch plywood and cut along the lines using a jigsaw. Also mark the outlines for the sink or range top on the plywood and cut around these marks with a jigsaw.

Lay the cut plywood sheet on a sheet of concrete backer board. Trace around the outline of the plywood countertop on the backer board. Also trace the sink and range top holes. Score the straight line on a backer board with a utility knife and bend it until it snaps into two. Alternatively, outline a curved line with a nail hole punch and push the board from within the lines.

Dryfit the backer board on the plywood, and lower this assembly on the cabinet. Check that the range top and sink holes match up, or outline the excess on the plywood or backboard and trim it with a jigsaw or utility knife. Separate the board from the plywood.

Center and lower the plywood on the cabinet. Drill 1 1/4-inch pilot holes around the edge of the plywood, spaced 5 inches apart. Drive screws into the holes to secure the plywood to the cabinet. Ensure the screw heads fall flush with the surrounding surface.

Prepare a batch of thinset mortar in a plastic bucket according to the directions on the label. Use a notched trowel to scoop up some mortar and apply it evenly over the plywood to create a 1/8-inch-thick layer.

Center and lower the backer board over the mortared plywood. Press the backer board to form a secure bond with the plywood.

Drive roofing nails every 6 to 8 inches along the edge of the backer board to secure it to the plywood directly below. Also insert nails through the center and around the sink and stove top holes.

Spread 1/8-inch-thick layer of mortar over the backer board, enough for four to six tiles, and begin laying the tiles in your desired pattern. Cut the tiles to size with a tile saw.