Transform your countertops from tired to trendy with this DIY guide
If you’re looking for a trendy countertop upgrade, you may want to consider concrete. This chic option is comparable in price to high-end countertops like marble and quartzite but a bit easier to customize. Keep in mind, this isn’t a good project for a beginner, but if you have experience pouring concrete and installing countertops, DIY concrete countertops can save you some cash. This guide will show you how to make concrete countertops in 16 steps.
Though concrete countertops come with many pros, one thing you’ll need to watch out for is weight. These countertops are extremely heavy, and you might need to reinforce your cabinets to carry the load. For this step, you may want to consult a professional.
Once your cabinets get the okay, you’ll need to figure out how much concrete to buy. Different concrete countertop ideas have different requirements, but most countertops are 1 1/2- to 2 inches thick. Multiply your countertops' width, length, and thickness to get the total cubic feet. An 80-pound bag of concrete mix yields 0.6 cubic feet of concrete, so plan accordingly. It’s better to have too much concrete than too little.
If you haven’t already measured your countertops when purchasing concrete, you’ll need to get exact measurements to make a mold. Measure your base cabinets, and add 3/4 inch to the length and width to account for overhang.
To create your mold, use a melamine-coated particleboard. This type of particleboard has a sleek white surface that gives your countertop a smooth finish. Place the board on a couple of sawhorses to create an accessible workspace.
Next, use your measurements to draw an outline of your exact countertops on the melamine. This pattern will turn into the base of your mold. Cut out the outline with a circular saw.
Then, you’ll need to build the sides of the mold. Cut strips of particleboard that are 2 3/4 inches wide (or your preferred thickness). When sizing, remember that most concrete countertops are 1 1/2 to 2 inches thick. Once cut, screw the strips into place on the sides of the base; make sure to insert your screws from the outside of your mold so you can remove them when the concrete cures.
Instead of cutting your countertop after the fact, you’ll create the cutouts for a sink, cooktop, or other accessories before pouring your concrete. Make sure you take exact measurements of these accessories and their location on the countertop. If there’s an error, the accessories may not fit when you try to install them.
Use your measurements to trace an outline of the accessories in their exact location on the base of your mold. Drill pilot holes on the inside corners of each section you plan to cut away, then use a jigsaw to cut out the outline.
Measure and cut strips of particleboard to use as the sides of the cutouts. Attach them the same way you attached the outer sides of the mold. Clean your mold so it’s free of sawdust and other debris. Debris could blemish the top of your counter once the concrete cures.
To prevent concrete from slipping through the cracks of your mold, you’ll need to caulk around the seams—the areas where the sides of the mold meet the base. If you’re inexperienced with a caulk gun, it’s a good idea to line these areas with painter’s tape and then caulk over the tape. This way, if you make a mistake, you can pull the tape up and try again.
If your silicone caulk is a little messy, run a wet finger along the caulk before it dries to create a smooth line. Wait 24 hours for the caulk to completely dry, then spray the entire mold with silicone spray or olive oil. This will prevent the concrete from sticking and make removing the mold easier.
It’s worth repeating that concrete countertops are heavy, so creating a support frame for your mold is a good idea. You don’t want the particleboard to bend and warp the shape of your countertop. You can do this by screwing together a few two-by-four boards, cut to size.
Cut at least three two-by-four boards so they’re 3 1/2 inches longer than the base of your mold. Place them on the sawhorses beneath your mold to create the base of your support frame. Center the mold on top.
Next, measure and cut two-by-four boards for the sides of your support frame. The sides of the support frame should fit snugly against the sides of the mold. Screw the sides to the base of the frame from underneath. Do not screw the two-by-four to the mold itself—only the support frame.
You need to reinforce concrete countertops with galvanized steel mesh, which helps prevent cracking. You’ll add this mesh halfway through the pouring process, but you should prep it beforehand.
Measure the mesh to create a shape that’s 1 inch smaller than the shape of your countertops. Snip the mesh to size using a metal cutter.
Follow the manufacturer’s instructions to mix the concrete, taking care to add the correct amount of water. There are different methods to mixing, including using a motorized concrete mixer, but a wheelbarrow and shovel (which you probably already have in your shed) will work just fine.
Depending on your kitchen countertop idea, you may want to add a concrete pigment—whether it’s a powder or liquid. Mix it into the concrete following the manufacturer’s instructions. If you use a liquid pigment, you’ll need to adjust the amount of water in your concrete mix so it isn’t too runny. The ideal texture is similar to peanut butter.
Begin pouring the concrete into the mold. Use a hand trowel to help spread the concrete and tamp it down. Fill your mold halfway.
Once the mold is halfway full, add your mesh reinforcement. Place it in the center of the mold, but do not allow it to touch the edges. You don’t want wire showing through the edge of your countertop.
Continue to fill your mold with concrete over the wire. Tamp it down with a trowel as you go. Make sure to slightly overfill the mold since the level will drop once you settle the concrete. Once it’s filled, smooth the surface with your trowel.
You’ll need to settle the concrete to bring any air bubbles to the surface. Air bubbles ruin the smooth, professional texture of a concrete countertop. They can also cause cracking. To do this, lightly tap a rubber mallet along the sides of the mold. You’ll notice the concrete start to level out—but don’t tap it hard enough that it starts spilling over itself.
Alternatively, you can use an orbital sander without any sandpaper. Run it along the sides of the mold. This should vibrate the concrete enough to bring the bubbles to the surface.
Let the concrete set so that it’s slightly hard but still malleable, then use a hand trowel to smooth the surface. The top of your mold will become the underside of your countertop, so make sure the concrete is level.
Once it’s level, lay a plastic sheet over the top of your mold. This protects the surface from dust and debris while locking in moisture so the concrete can cure slowly. A slow cure will help strengthen your countertops.
Allow your countertops to cure fully. You should wait at least a week before you attempt to remove the concrete from the mold. For the strongest countertops, wait two weeks.
Once your concrete has cured, you can remove the mold. Start by removing the screws with a drill and pulling the sides away. The melamine particleboard should smoothly release if you used silicone spray or olive oil.
Once the countertop is out of the mold, turn it over. The top of the mold is actually the bottom of your countertop. This way, your countertop is less likely to have visible air bubbles. Be extremely careful during this process as the countertop can be quite heavy.
If you notice any cracks or bubbles, you can repair them using a concrete patching compound. Apply the compound per the manufacturer’s instructions. Allow it to cure fully, then use an orbital sander to smooth the surface.
You can also use your sander to smooth rough corners. Start with 100-grit and move to 220-grit. Since this kicks up a lot of dust, you should wear a respirator.
Afterward, thoroughly clean the surface of your countertop (avoid acid-based cleaners, which can damage concrete) and allow it to dry.
Since concrete is porous, you’ll need to seal your countertop to prevent staining. Per the manufacturer's instructions, apply a concrete sealer using a sponge or brush. Typically, the sealant only takes about 30 minutes to dry. Once your countertop is sealed, it’s ready for installation.
If you hire a professional, concrete countertops cost $5,000 to $10,000 on average, depending on the size. This is rather pricey compared to other popular countertop options. For example, Corian countertops cost about half as much, and laminate is even more affordable.
Despite the high price tag, this may not be the project to DIY unless you have a lot of experience. You’ll save $30 to $90 per hour on labor, but a mistake can lead to costly damage—especially if there’s water damage. It’s also relatively difficult to make a concrete countertop that’s level and without imperfections. You won’t save money if you have to do the project twice because you ran into issues the first time.
To get the best deal, interview at least three countertop contractors near you. Make sure you choose a contractor with experience using concrete.
Not every concrete is right for a countertop. Ideally, you’ll use a specific concrete countertop mix, which you can pick up online or at your local hardware store. This type of concrete contains smaller aggregate pieces and plasticizer additives that help you get a smooth, even finish. Depending on the brand, they also cure more quickly—in as little as 18 hours.
Concrete countertops are not a beginner DIY. You must take precise measurements, create an exact mold, and meticulously pour your concrete. Any error could lead to issues both in appearance and fit. You may find that your sink won’t fit in the cutout or your countertop is wobbly and unlevel.
Your cabinets could buckle under the added weight of concrete if you don’t properly reinforce them. Beyond that, your countertop could crack, bubble, or have an unprofessional finish. That said, it’s certainly a doable DIY for someone with concrete experience.
DIY concrete countertops are actually still relatively high cost compared to other countertop types. You can expect to spend $65 to $135 per square foot on materials. This is more than twice as expensive as laminate, which costs $25 to $55 per square foot, and even more expensive than granite slabs, which cost $40 to $60 per square foot.
That said, if you do the job DIY, you can save on labor costs. Labor typically costs $30 to $90 per hour.
