How to laminate a countertop
A laminate countertop installation is basically a grade-school cut-and-paste project writ large. You build the substrate, cut out the laminate, and paste the two together with contact cement.
Starting with the proper substrate creates a good foundation for the countertop. Particleboard has a uniform, clear surface perfect for accepting the contact cement and leaving a smooth finish. Unfortunately, it doesn’t come any thicker than 3вЃ„4 inch, which isn’t enough for a countertop. You’ll need to double up at the edges to create a 1ВЅ-inch face and raise the counter higher.
This Old House general contractor Tom Silva prefers particleboard to MDF, which is too susceptible to expansion and contraction from water. However, he makes sure to paint the underside of any counter that will sit over a dishwasher, washing machine, or dryer with a thick coat of primer to protect against moisture.
Pasting the laminate to the particleboard is the trickiest part of building a counter. Two surfaces coated with contact cement bond the moment they touch. “You have to have both parts lined up correctly,” says Tom. “Because once it’s stuck, it’s stuck.” Separating the two surfaces with dowels will give you the chance to line everything up before you adhere the parts.
There’s a sequence to the way you laminate any counter in order to hide visible edges. The side edges go on first, then the front edge, and finally the top. Each piece of laminate should be cut larger than the surface and trimmed flush with a small router and a file before the next piece goes on, ensuring a tight seam at all corners.
Matching laminate edges is very difficult, which is also why you should plan for as few seams as possible; if they are necessary (as with an L-shaped surface, like the one shown here), your best bet is to laminate two pieces separately, then join them. You can also choose to make a backsplash piece, which attaches to the back of the counter before you mount the whole slab to the cabinets or the wall.