How To Install A Kitchen Counter - Cutting Sink Hole In Laminate, Joining Corner Miters, L-Shape

Installation of new laminate countertop in a kitchen.

New House Kitchen:

Installing A Laminate
Kitchen Counter

In This Article:

Sections of counter are checked for fit. Wall interferences are cut away. The sink hole is cut out. Mitered corners are glued and bolted together. L-shaped sections are screwed to tops of cabinets.

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Skill Level: 3 (Moderate)

Time Taken: 2 Hours

By Bruce W. Maki, Editor

Installing a pre-formed laminate kitchen counter, the type with the backsplash already attached, can be a simple job or a difficult job. The task is easy if it's a single piece, straight counter that does not need to be shoe-horned into a space between two walls. But the work is much more challenging, as this articles shows, when the counter has to be assembled and fit into a tight space.

First I used a framing square to check the straightness of the walls. They weren't.

I placed the long section of counter on top of the cabinets to see how badly the fit would be. With the counter pushed against the wall, there was a 3/8" gap at the mitered end.

The poor fit was caused by a bulge in the exterior wall, possibly caused by sloppy framing or just by the natural tendency of lumber to warp and twist over time. Truly good framing carpenters would have checked their work and planed off the excess material. Now that the drywall is installed, that option is out of the question.

This photo shows the bulge that caused me so much trouble. The other problem with this kitchen is that the kitchen designer specified an arrangement of cabinets that fit exactly into the room dimensions on the blue prints.

The trouble is, as anybody with an ounce of construction experience knows, Nothing Ever Goes As Planned. The natural and unavoidable inaccuracy in the framing process mean that you cannot rely on cabinets fitting exactly into the dimensions on the blue print.

Over the years I have learned that finish carpentry involves many techniques to work around the all-too-common situations where walls are not plumb, rooms are not square, and floors are not level. But when the designer of a project does not appreciate these realities, they assume that the cabinet installer can fit their 108" of cabinets into the 108" that the blue print says is available. But, like I said earlier, Nothing Ever Goes As Planned.

When I saw the plan for this kitchen I immediately measured the room... and amazingly, it was exactly 108" wide, and the diagonal measurements were within 1/8" of each other. "Good", I exclaimed to the homeowner, "maybe we will be able to fit the counter tops and the stove into the 108" wall." Then I discovered the bulge in the wall.

Correcting The Problem

Normally I use a power sander, such as a portable belt sander, to remove some of the backsplash. If only 1/8" is removed, or less, then the homeowner will probably not notice the narrow spot. In this kitchen I consulted the homeowner, who was very understanding, and we agreed that the best approach was to cut the drywall away so the counter would fit into a notch. But this still shows up as a narrow spot on the 1" deep backsplash.

But First... The Kitchen Sink

The first step in cutting the sink hole is to lay out the location of the sink. I put a piece of masking tape on the counter to mark the center line. The front-to-back position has to be carefully checked:

If the hole is too far forward, the front panel of the cabinet will interfere with the sink installation.
If the hole is too far to the back, the edge of the sink will hit the backsplash.

Stainless steel sinks have a channel welded to the underside, at the edges, where special screw-fasteners grab and clamp to the counter top. The outer edge of the channel defines the size of the hole in the counter top.

Once the sink position has been determined, I use a pencil to mark where the edge of the basin will be.

Then I apply a piece of tape and measure inwards a small distance, 5/16" in this case, and make a mark. This is the edge of the hole.

At each corner, I apply a strip of masking tape, and measure in 1-1/4" from the cut lines. This is half the diameter of my 2-1/2" hole saw. I mark the center of the hole.

Using my most powerful electric drill, I cut the holes.

The plug almost always gets stuck in these things. The fastest and easiest way to remove the plug is to drive in a screw and yank it out.

The layout and hole cutting are done with the counter sitting in it's proper position on top of the base cabinets.

The cutting of the hole, with a jig saw, was done in another room. I placed the counter upside down on several small stacks of 2x4 blocks, high enough to keep the backsplash off the floor.

I draw lines to connect the edges of the corner holes. I used a scrap of wood to keep the jig saw level while cutting along the step.

A photo showing the four holes.

The cutting is done from the back side, always. A normal jig saw blade cuts only on the up stroke, which means that the blade teeth are pulling the laminate into the wood backing. This solid support causes the laminate to shear away in clean little fragments. Cutting from the top side will make the laminate splinter badly, and the base of the saw might scratch the surface.

Notice the position of some of the support blocks. This arrangement supports the off-cut so it does not fall away and rip the laminate.

Connecting The Mitered Countertop Sections:

The first step was to lay out the counter sections, upside down, on a sturdy work surface. I used several cabinet boxes. There is a big piece of plywood under the joint, to provide a flat surface.

The connector hardware that holds the counter joint together.

Connecting mitered corner in laminate counter.

With the two sections placed close together, I applied a liberal coating of carpenter's glue to each edge. Then I installed the connectors and tightened them snug, but not too tight.

The following procedure took some time. I had to make sure the corners were aligned properly and that the seam was smooth (i.e. both sections at the same height). After the initial fitting, I removed the piece of plywood underneath so I could feel the seam.

I used a hammer to tap one section into alignment. When the seam was smooth I tightened the connectors, a little at a time. I also used a wet cloth to wipe the glue from the laminate side.

When the connectors were tight, I wiped away the excess glue and let the joint dry for a half hour. Overnight drying would be ideal.

Once the two sections were joined and the glue had time to set, the counter was carefully placed back on top of the cabinets. I am very cautious about lifting counter tops after the sink hole is cut, because there is very little structure left around the hole. I have not broken a counter yet. In this case I had a helper assist me with moving the counter.

With the counter positioned as close to the wall as possible, I drilled holes in the triangular brackets at the corners of the cabinets.

Then I installed drywall screws to fasten the counter to the cabinets. I made careful measurements to make sure the screws did not pierce the top surface.