How to Build a Countertop the Easy Way

Before you build your countertop, remove your existing countertop. This requires a few steps. First, turn off the water supply in your house before you touch the plumbing. Don’t forget—the consequence is some serious water damage. After that:

• Loosen plumbing connections

• Disconnect water lines and garbage disposal units

• Remove your sink and any appliances that might be in the way

• Remove doors and drawers on base cabinets

The last step is optional, but it does help prevent damage and makes installation a bit easier. You’ll need to use a pry bar to pry up your existing countertop. Make sure to remove screws and other hardware, though you may be able to reuse support brackets. Be careful not to damage your cabinets.

Once you remove your existing countertop, use your measuring tape to measure the size of your counter. You’ll need to get the width, length, and depth of the space. You can do so by either measuring:

• The countertop you just removed

• The top of the base cabinets, adding 1 inch for overhang on exposed edges

It may be helpful to trace a template on cardboard—especially if your countertop has curves or unusual angles.

Some DIYers prefer to start their cabinets with a layer of MDF or plywood before layering wood boards or tongue-and-groove flooring. Others directly install the wood boards. Whatever method you use, you’ll need to mark and cut the wood boards per your countertop measurements. 

Mark your cut lines with a pencil, using a straightedge to make sure the angles are precise. Remember, you’re likely working across multiple boards that you’ll join together later. Most will require vertical cuts, but you may need to cut one lengthwise to get the right fit.

Double-check your work, then cut the wood pieces along the cut lines using a circular saw.

Tip: Pay attention to the direction of any visible wood grain. You want to make sure the grain lines up between boards for a professional-looking countertop.

Unfinished wood countertops may have minor imperfections, especially along cut lines. Use medium-grit sandpaper to sand down the wood. Finish with fine-grit sandpaper. If you’re using flooring planks, you may not need to sand them at all.

If you’re not using tongue-and-groove floor boards, biscuit joints can strengthen your countertop. Look at where your boards will connect. Mark slots for the joiner biscuits along the edges that will meet, spacing the slots about 12 inches apart in the center of the edge. 

Make sure the slots line up between boards, then use a biscuit joiner to cut the slots for the joiner biscuits.

Once you’ve cut the slots, it’s time to insert the joiner biscuits. Each board (aside from the boards that make the outer edges of the countertop) should have:

• One edge with biscuits, which you’ll insert into the slots on an adjoining board

• One edge with empty slots, ready to receive biscuits from an adjoining board

For this step, don’t worry about the receiving slots. Simply use wood glue to attach the biscuits to the penetrative edges only. Wipe away excess glue using a damp cloth, and wait for the glue to dry per the manufacturer’s instructions.

Next, you’ll glue all the boards together. Apply wood glue in the remaining biscuit slots and along the adjoining edges of each board. Join the boards together, inserting the biscuits from one board into the slots on the adjoining board.

Continue working your way through until all the boards are glued together. Wipe away any excess glue with a cloth.

Place large clamps (evenly spaced apart) on the boards to hold them tightly in place as they dry. You may even want to place a heavy object on top of your countertop, so the wood can’t warp while the glue sets. Let the glue dry per the manufacturer’s instructions.

Once your boards are firmly glued together, it’s time to finish your countertop. There may be areas—particularly the joints—that look uneven. Sand them down with fine-grit sandpaper. Use a level to make sure the countertop surface is level. Clean the surface using a damp cloth.

It’s easier to stain your countertop before you install it, though some homeowners choose to skip this step and finish their countertop with a food-safe mineral oil (especially if they are finishing a butcher block counter). If you do want to stain your countertop, start with a wood conditioner (or pre-stain) to prep the countertop. Apply an even coat per the manufacturer’s instructions using a foam brush.

Next, use a foam brush to apply two coats of wood stain. You can use a paintbrush to get hard-to-reach edges. Apply per the manufacturer’s instructions. Allow the product to dry between coats and before sealing your countertop.

Tip: If you’re installing a kitchen countertop, make sure you use food-safe finishes—whatever the type.

Wood is porous, so sealing can prevent stains and extend the life span of your countertop. Use a polyurethane topcoat (food-grade if you’re installing it in a kitchen) and apply it per the manufacturer’s instructions. Allow the sealant to completely dry.

There are a few different ways you can install a countertop. Some people prefer to bring in pros—especially if it requires plumbing work and serious appliance installation. Otherwise, start your installation by lining the top edge of your base cabinets with a layer of wood glue. Line up and attach your countertop, then clamp it down in place until the glue dries per the manufacturer’s instructions. You may need a friend to help you with this step.

Next, you’ll need to add an extra layer of security. If your base cabinets already have support brackets in place from your previous countertop, you can reuse them. If not, attach brackets along the top inside edges of your base cabinets, and screw your countertop in place. Some people also use finishing nails along the outer edges if they have particularly thin countertops, but brackets prevent visible nails.

Don’t forget to reconnect your plumbing, reinstall your sink and appliances, and replace your cabinet doors and drawers once your countertop installation is complete.