Measure the opening of your sink by flipping it over and measuring the base from edge to edge on each side. If your sink is still in the box, it will list the required space for the opening. If you’ve installed the cabinets yourself, make sure that you have a level line running along the top by placing a level over each individual cabinet and measuring the distance from the floor to the top. Use shingles to raise a cabinet if you need to adjust its height to make them level. Add 1 in (2. 5 cm) to each side that will lead to a rounded corner if you aren’t ordering countertops with 90-degree corners.

If you really want to make sure that the countertop fits perfectly, have the distributor take measurements for you. It may cost you a little more, but it’ll ensure that you get a perfect fit. The distributor will determine how many pieces your countertop will come in. Most of the time, it will arrive as a single piece.

If it doesn’t fit, measure it and double-check your original measurements to ensure that the manufacturer didn’t make a mistake. If they did, contact them directly to get them to replace it.

Custom-sized counters often come with the pilot holes, brackets, and screws to install it. You can skip the corresponding steps if this is the case. Corner brackets are sometimes called L brackets. They’re L-shaped or triangle-shaped brackets with flat sides and they’re used to attach flat surfaces that are perpendicular.

Place your brackets so that they rest squarely in the corner where your counter meets the cabinets. If your cabinet comes with pre-fitted slots for your screws, you do not need to drill pilot holes. If the brackets weren’t provided, you can purchase them from a local hardware store.

Before you drill, hold the bottom of a screw flush against the side of your countertop to make sure that you aren’t going to drill through the countertop completely. For a countertop without screw slots and screws, drill #4 wood screws into your 5⁄64 inch (0. 20 cm) pilot holes.

Let your backsplash air dry for 30-60 minutes before adding the caulk around the edges.

If you’re using this method, you are going to be laminating the countertop before you install it later on.

You’re going to trim the excess portion of laminate later, so don’t try to fit it perfectly.

You don’t need to worry about getting a perfect line since you’re going to trim the edges down anyway.

Do this in a well-ventilated area. While it isn’t toxic, contact cement can smell kind of bad. Don’t worry if the cement starts to dry—it’s supposed to do that before you attach it.

Wait another 15-20 minutes to let your countertop dry.

You have to use dowels that are a few inches longer than your countertop on either side.

You can adjust the sheet slightly once you’ve placed it down, but you have to be careful to not let your laminate come in contact with your countertop. Contact cement will bind them instantly together if you do.

The laminate and countertop will be instantly and permanently joined, so avoid air bubbles by not lifting your hand off of the laminate as you press down. Depending on how long the dry time is, you might want to use some type of clamps or some type of heavy weight objects to hold it down in its proper position. [20] X Expert Source Patrick JohnsHome Improvement Specialist Expert Interview. 26 October 2021.

You can enlist the help of a friend to remove the dowel for you if you’re nervous about accidentally creating an air bubble.

Press downward while moving your router to guide it along the line. You don’t need to cut it so that it’s flush with the counter.

Place your counter on top of the cabinets and use the cabinet walls as a straight edge to outline where they meet the countertop with a grease marker or carpentry pencil.

Some construction adhesives come in a squeezable bottle. You don’t need to use a brush in this case. Work in a well-ventilated area; construction adhesive can be quite pungent. Liquid Nails is a popular, inexpensive brand of construction adhesive.

You can use a rubber mallet instead of a hammer if you’re really worried about damaging your countertops. Let your countertop air dry for 24 hours before using it.