Measure the width and length of the cabinets or other area where you want to install the countertop.
Set up two saw horses in an outdoor location or in the garage. Place one piece of 3/4-inch-thick particle board on top of the saw horses. Open a tube of construction adhesive by snipping the end off using scissors. Insert the tube into a caulk gun and apply it in a zigzag pattern over the entire surface of the board, extending it to 1/2 inch from each edge.
Place a second piece of 3/4-inch-thick particle board on top of the first aligning the edges perfectly. Insert finishing nails through the top board every 6 to 8 inches using a nail gun to hold the boards together.
Reduce the length or width of the particle board if it is larger than the size of your installation area. Place a tape measure on top of the boards to determine the length and width dimensions and mark them with a pencil. Don safety glasses and cut along the pencil lines using a circular saw. If the board is already the proper size, skip this step.
Place a piece of laminate on a work table and draw the dimension of the counter on the backside of it with the tape measure and the pencil. Cut out the laminate using a jig saw. Cut an additional strip of laminate that is 1 1/2 inch wide and the same length as the counter to cover the front edge. Cut an additional one to two strips for each side edge, depending on if they will remain exposed after installation.
Open a can of contact cement and use a paint brush to apply it to the entire top of the particle board counter and the backside of the laminate sheet. Wait until the cement is no longer wet to the touch.
Lay wooden dowels across the particle board spaced at 2-foot intervals. Place the laminate glue-side down on top of the dowels. Once it is positioned properly, pull the dowels out and press the laminate down. Roll the laminate from the center to the edges using a laminate roller.
Apply the front edge laminate strip and the side laminate strips in the same manner.
Carry the countertop into the basement with the help of another person. Always turn the counter on the side when carrying it to prevent it from cracking. Place the counter into position on top of the cabinets. Open the doors of the cabinets, if applicable, so you can easily see the underside of the counter.
Place a metal L-bracket on the underside of the counter so that one leg is on the counter and the other is on the cabinet. Insert 1-inch long wood screws through each hole using a power drill.
Insert additional metal L-brackets every 2 feet along the entire underside perimeter of the counter to secure it.