The benchtop can visually dominate a kitchen, so if it’s showing its age it can bring down the overall look of the space.

You need to measure to the exact millimetre before ordering a new benchtop, then plan the installation carefully for the best results.

TIP Take your measurements to the special orders desk of your local Bunnings to order the benchtop.

Draw an accurate sketch

Before you begin, ask for measuring instructions from your supplier.

The most accurate method is to order the benchtop using the existing one as a template.

Alternatively, measure the cabinet dimensions and make a sketch of your kitchen.

Indicate where the ends of the benchtop don’t butt into a wall and end caps are needed.

The supplier will convert these details to a benchtop order, including allowances for overhangs.

Cut a mason’s mitre

A mason’s mitre is a type of joint traditionally used in stonework but now commonly used for benchtops.

The two parts being joined meet as a butt joint with a small mitre at the inside edge.

This reduces wastage and makes the corner easier to install.

Straight 2400 x 600 x 25mm lengths of laminate benchtop are available for as little as $99.

If your layout has internal corners, we suggest you get the mason’s mitre cut by a specialist.

It’s also best to call in the experts to help install a U-shaped bench enclosed by walls.

Installation guide

To avoid unpleasant surprises, follow this checklist.

MEASURE YOUR CABINETS carefully, because if they are a different size from the standard 560mm depth, you’ll have to order custom benchtops.

CHECK THE THICKNESS of the old benchtop. This is particularly important if the splashback rests on the old benchtop and is being left in situ, because if the new benchtop is a different thickness, it will not fit properly.

USE A STRAIGHTEDGE to check the walls are straight and use the 3-4-5 method to check the inside corners are exactly 90º.

If the long side of the triangle deviates more than about 5mm in 1500mm, discuss the situation with the supplier.

They may be able to cut the mitre to compensate for a corner that is severely out of square.

Step 1. Remove the old benchtop

Shut off the water supply then disconnect the plumbing. Unclip the sink, prying up the edges to remove it. Inspect the underside of the benchtop and remove all screws securing it. Slice through the silicone along the splashback then lift out the benchtop.

Step 2. Scribe the benchtop

Position the new benchtop and check the back edge fits along the walls. If the walls aren’t straight and there are visible gaps wider than 5mm, apply masking tape to the laminate edge then use a pencil and compass to mark a scribe line onto the tape.

Step 3. Trim the edges

Remove the benchtop and clamp it firmly on a pair of sawhorses. Use a belt sander fitted with an 80 grit belt to carefully sand to the scribe line. Replace the top and check the fit against the walls, making sure the front is parallel with the cabinet faces.

Step 4. Check the overhang

Use the compass or a steel rule to measure the benchtop overhang is at the required distance at the stove and refrigerator openings. If the appliances fit tightly between the cabinets, the capped overhang can be reduced by scribing and sanding the other end.

Step 5. Join the mitre

Apply a continuous bead of clear silicone along the raw edges of the joint then push the pieces together and add the connector bolts. Use a hammer and scrap timber to tap along the joint from above until the surfaces are flush then tighten the bolts fully

Step 6. Secure the benchtop

Drill pilot holes through the cabinet attachment cleats and secure the top using 30mm x 8g particleboard screws. Hold the top down to keep it from lifting as the screws are secured. TIP If cleats aren’t available, use metal angle brackets and shorter screws.