How to Install Prefabricated Granite Countertops

Measure the dimensions of the existing countertop. Note the locations of electric outlets. Ask a professional to cut the granite countertop in the desired measurements. The vendor polishes the edges of the slab to give it the required finish before installation.

Position the tip of a putty knife over a section of the caulk around the sink and tap it gently with a hammer until it breaks. Slide a pry bar into the gap between the broken caulk and slide it around the perimeter of the sink to loosen it. Lift the sink out of its hole and set it aside.

Remove the old countertop and prepare the substrate. Loosen and remove the screws holding the old countertop in place, or tap the adhesive with a hammer and putty knife. Lift and remove countertop sections as they become loose.

Spread a cloth over a level surface and lay perpendicular mitered pieces over it for an L-shaped countertop, with their bottom sides facing upward. Apply adhesive caulk over the mitered ends of adjoining pieces and press them tightly together.

Slide I-bolts into the slots in the mitered corners and tighten these partway. Wipe excess caulk with a rag, check that the mitered joint is level before tightening the screws.

Hold one end of the prefab countertop and assign a helper to hold its other end. Center the countertop over the plywood surface before lowering it.

Drill evenly spaced screw holes through each corner brace of the cabinet and extend these into the countertop’s lower surface. Avoid drilling the holes too deep so the screws are not visible through the surface of the countertop.

Insert 1-1/4-inch wood screw into the holes to secure the countertop to the braces. Install the sink in the hole and caulk its edges so it sets in place. Leave the caulk to dry for the time on the label directions before using the sink.