The Cheapest Way to Install a Kitchen Countertop Over an Existing One

Clean the countertop surface with a scrub brush and kitchen cleanser to remove any dirt and to scratch the surface slightly with the abrasives in the cleanser. Wash the countertop off with clean water and dry it with a towel.

Repair any gouges or cracks in the countertop with a repair paste formulated for your particular countertop type. Use a putty knife to push the repair paste into the damaged area. Scrape along the top of the patch with the knife's edge to smooth it out then allow the paste to dry for two hours.

Sand the entire surface of the countertop, including its sides, with 120-grit sandpaper to create a surface to which the thinset mortar can easily adhere. Wipe the countertop with a clean dry cloth, after sanding, to remove any dust.

Mask off the edges of any adjacent surfaces to avoid splash-over of the thinset. Place a drop cloth on the floor, as well, to catch any spillage.

Stir a bucket of premixed thinset mortar with a wooden stir stick until it's smooth and ready to spread. Use a notched trowel to spread the thinset over the countertop in a 1/4-inch layer, covering the existing countertop. If the countertop is tiled, make sure you get the thinset firmly into the grout lines. Cover the sides of the countertop with the thinset as well. The thinset should be thick enough to hold vertically without slipping off the trowel. Smooth out the thinset with the trowel, creating a smooth and level surface to apply the laminate sheeting. Allow the thinset to dry overnight.

Measure the countertop surface with a tape measure. Add 1/4-inch to the measurements to allow for trimming. Transfer the measurements to the laminate sheet you want to use as your new countertop then cut it with a router to fit. Test-fit the sheet onto the countertop, making sure that it fits evenly against the backsplash along the wall. Make any adjustments needed with a utility knife.

Brush a layer of contact cement onto the rear of the laminate sheet and onto the thinset-covered countertop. Allow the cement to dry until it's slightly sticky to the touch. Place a series of wooden dowels across the countertop, one every 6 inches or so. Place the laminate sheeting onto the dowels and position it in place over the countertop. Remove the dowels one by one from the countertop, allowing the sheeting to contact the cement on the countertop gradually. This will prevent an initial misplacement of the sheet as the cement bonds instantly. Continue until all dowels are removed and the sheeting is in place.

Roll over the laminate sheeting to ensure it sticks completely to the thinset with a laminate roller. This also removes any air from beneath the sheeting.

Trim the sheeting with the router to fit the contours of the countertop.

Measure the height of the countertop edge and locate a trim piece that matches or slightly exceeds the height. Brush cement onto the thinset-covered edge and the rear of the trim then press the trim into place once it dries sufficiently. Go over the trim with the roller then trim with the router as needed.

Fill the gap at the rear of the laminate sheet and the wall with silicone caulking. Use a file to buff down the joint between the top sheet and the trim until it's smooth. Use a wet thumb to smooth the caulk then allow it to dry for two days before removing the masking tape and drop cloth and using your new countertop.