If you have built a counter, and will be installing a countertop, you will need to install plywood before you install the new countertop. If you want to replace your old countertop you will need to install plywood on the counter before installing the new countertop, as the existing plywood may be damaged or warped. Plywood can also be used on counters to raise the level of the countertop.

1. Step 1

   Use a cordless drill to remove all of the screws that hold the existing countertop and plywood in place. You can find the screws that hold the countertop to the plywood under the counter. The screws that hold the plywood to the frame of the counter are usually put in down through the top of the plywood and into the frame so they should be visible once the old countertop is removed. Once all screws are removed use a claw hammer or a pry bar to lift and remove the countertop and old plywood.

2. Step 2

   Use a tape measure to determine the length and the width of the counter. Measure all the way to the edges.

3. Step 3

   Use the tape measure, a straight edge, and a marking pencil to measure and mark the new plywood according to the counter measurements. When you mark the new plywood use the straight edge to make crisp, clear lines directly on the wood.

4. Step 4

   Put on protective eyewear. Take the marked plywood to your work shop, or outside to cut so that the dust is not released into your home. Use a skill saw to cut the wood to size, cutting on the lines you made with the marking pencil and straight edge.

5. Step 5

   Sand all edges of the plywood using a fine grit sanding block. Do this to remove all cut marks and/or rough edges which may show on the edges of your counter. This will allow you to have a smooth surface to paint or tile.

6. Step 6

   Bring the sized plywood into the house and lay it on the counter straight. All edges should be even and flush. Use a cordless drill and 2 inch wood screws to secure the new plywood to the counter frame. Drive the screws down through the top of the plywood, ½-inch from the edges of the counter, every 2 to 3 inches around the entire perimeter of the counter.