Concrete countertops offer a unique, customizable alternative to traditional stone surfaces at a fraction of the cost. With their heat, scratch, and stain resistance, they’re gaining popularity for both kitchens and bathrooms. Each of them is one-of-a-kind—you can mold them to fit any shape or size, and tint and texture them to match the rest of your space. Watch as This Old House host Kevin O’Connor explains how a typical concrete countertop project works, from templating to final installation.
Planning Your Concrete Countertop
Before you embark on a concrete countertop project, consider these factors:
- Countertop layout: Take accurate measurements, and factor in special features you’ll need for the countertop like sink cutouts and embedded hardware.
- Maintenance: You’ll need to block out some time for routine sealing to preserve the counter’s stain and moisture resistance.
- Staining: A food-safe concrete stain can add a splash of color to your countertop.
- Texturing: Add texture to your concrete countertop by embedding pieces of glass, metal, or other materials into the surface. You can also use specialized tools and techniques to make a unique surface pattern.
- Type of mix: Choose the right type of concrete mix for the project. Some are designed explicitly for countertops and contain pigments and aggregates for color and textures.
- Weight: Concrete countertops are heavy, and the cabinets underneath will need to bear the weight. You may need to install additional support underneath.
A countertop-specific concrete mix contains finer aggregate that results in a smoother surface, plus specialty additives that make the cured concrete stronger. Countertop mix is also available in white, which can be tinted with powdered or liquid pigments to create a wide range of colors. To lessen the chance of cracking, reinforce the countertop with a piece of wire mesh cut 2 inches smaller than the form on all sides.
Materials
- Concrete mix (specifically formulated for countertops)
- Concrete sealer
- Fiberglass mesh
- Luan plywood (¼-inch thick)
- Melamine boards (¾-inch thick)
- Rigid foam insulation (optional)
- Silicone caulk
Tools
- Circular saw
- Drill
- Grinder
- Hot glue gun
- Level
- Measuring tape
- Mixing bucket
- Sander
- Trowel
Creating the Template and Form for a Concrete Countertop
The first step in making a concrete countertop is to make an accurate template and form following your planned shape.
Use 1/4-inch Luan plywood and a hot glue gun to make a template of your existing countertop, cutting pieces as necessary with your circular saw. Try to make the template as sturdy as you can—any bending or distortion will affect the final result. Make notes as necessary where you’ll have cutouts for sinks and appliances.
Then, build the form by transferring the template measurements to 3/4-inch melamine boards. Cut the boards to size, including the top and side pieces. Screw the boards together, applying silicone caulk to any mitered joints. Finally, make any necessary cutouts.
Why Melamine? Melamine’s smooth, non-porous surface releases cleanly from cured concrete. However, keep in mind that while the flat sheet can be reused for future pours, the side pieces cannot — they absorb too much water and distort. That’s why wherever you have an inside corner, you should miter the ends so that no raw particle board is exposed. If you were to use a butt joint instead, the exposed particle board would soak up moisture from the wet concrete and compromise the form.
Mixing and Pouring the Concrete
Once you have your mold ready, mix and pour the concrete. Follow the manufacturer’s instructions for mixing ratios, and add any desired pigments or aggregates as you mix.
Spray a thin layer of concrete into the form as a base coat, then pour the remaining concrete into the form in sections. Add fiberglass mesh to reinforce the concrete, then compact the surface and remove air bubbles with a roller.
Technique Detail: After filling the form and troweling the concrete flat, use a long level to screed the surface level with the form walls, then work your floats across the top until the sound changes from a soft swish to a rasping scrape — a reliable indicator that the surface is properly finished. Use an edging tool to cut a slight radius into the concrete’s top edge. As concrete pro Mercado warns: “If you leave that sharp, it’s going to crumble.”
Curing and Finishing
Let the concrete cure for at least 24 hours, then remove the form. Once the form is gone, keep curing the concrete for an extra week to 28 days, depending on the mix you used.
Once everything’s cured, smooth any remaining rough spots and imperfections with a grinder. Then, apply a food-safe concrete sealer to protect the surface from stains and moisture.
Fixing Surface Voids: After demolding, you’ll likely find small holes left by air bubbles trapped during the pour. To fill them, mix up a slurry — essentially the same concrete mix but without any sand or fibers — and spread it across the entire surface, pressing it into every void. Once the slurry has cured, sand it off using a random orbit sander, starting with 80-grit sandpaper, then progressing to 100-grit and finally 220-grit for a smooth finish.
Installation and Maintenance
You’ve worked away from the kitchen so far, but now, you’ll install your concrete countertop in its final location. Have some helpers assist you with the heavy lifting for this step.
Apply a bead of silicone adhesive to the top of the cabinets. Then, carefully place the countertop onto the cabinets so it aligns properly. Follow the manufacturer’s instructions to let the adhesive cure.
Maintaining Your Concrete Countertop
Clean your countertop regularly with mild soap and water to keep it in top shape. Don’t use harsh chemicals or abrasive cleaners that could wear out the surface. You’ll need to reseal the countertop at least once yearly to maintain the protective barrier.
Even with careful maintenance, chips and cracks can still happen. Address them as soon as you see them to prevent further damage that could be expensive.
To patch small cracks, fill them with a color-matched epoxy or resin. For surface chips, use a concrete patching compound. Make sure you use food-safe products—other varieties use stronger chemicals that could harm your health if they leach into food.
Pro Tip: Tom Silva, This Old House general contractor, recommends two-part epoxy formulations for patching concrete: “I usually go with 2-part epoxy formulations because they’re extremely durable and have compressive strengths greater than the concrete itself. You have to protect your skin and ventilate the work area, but once cured, the stuff’s inert.” He also notes that if your countertop has been previously sealed, you should check with the sealer manufacturer to make sure the existing finish won’t interfere with bonding between the concrete and the patch.
