Concrete countertops provide a stylish, durable, and custom look for kitchens or bathrooms. Making your own concrete countertops allows you to mold them to your exact specifications. With some planning and effort, you can create beautiful concrete counters that will last for decades. This comprehensive guide will walk you through all the steps for making concrete countertops successfully.
Selecting the Concrete Countertop Materials
Choosing the right concrete mix and materials ensures your countertops cure properly and have the look you want. Consider the following when selecting supplies:
Concrete Mix
For countertops, use a high-performance or specialty concrete mix rather than a standard 5000 psi mix. Look for countertop mixes or mixes with polymer-modified resins that increase strength and reduce porosity. These improve water resistance and durability. White cement creates light gray counters, while black iron oxide dye makes dark charcoal counters.
Aggregates
Adding pea gravel or crushed glass aggregates creates exposed aggregate concrete with interesting textures. Larger aggregates like pebbles can also be added on the surface as an accent.
Reinforcement
Steel rebar or mesh reinforces the concrete internally. Look for rebar rods or welded wire mesh made from stainless steel or epoxy-coated steel to resist rusting.
Mold Material
Melamine-coated particle board or plastic laminate work best for mold materials. Avoid porous materials like wood that could absorb moisture and warp.
Release Agent
A release agent or mold coating ensures the cured concrete does not stick to the mold. Food-safe molds often have a polymer coating that acts as a release agent.
Color Pigment
Concrete dye, oxide powders, or liquid pigments color the concrete mix. Test small batches first to achieve the hue you want.
Finishing Products
Surface finishes like concrete sealers, polishers, or waxes protect the counters and provide different looks, from glossy to matte.
Texturing Tools
Items like rollers, brushes, and trowels can imprint textures on the surface when wet. You can get creative with textures.
Planning Your Concrete Countertops
Careful planning ensures your counters fit your space properly and support loads. Consider these key points while designing your counters:
Counter Measurements
Take precise measurements of existing cabinets and spaces so your counters will have the correct dimensions. Standard counter depths are 25-1/2”. Allow a 1/4” overhang on the front edge.
Countertop Edge Styles
Determine the edge style, like eased, bullnose, ogee, or cove. Simple eased edges are easiest for DIYers. If installing a sink, factor space for the faucet and backsplash.
Joint Placement
Decide where seams or joints will go. Joints at inside corners or strategic locations like near the stove or sink hide them well. Avoid joints near cabinet edges.
Support and Loading
Counters should sit on sturdy base cabinets, with added support from corbels or brackets if spanning large gaps. Properly reinforced overhangs prevent cracking.
Drainage and Plumbing
Include plans for the sink, faucet, soap dispenser, and drain pipes. Position drain openings accurately to match up with plumbing.
Finishes and Textures
Pick surface textures and finishes. A sample board with different techniques helps visualize the options. Gather any tools needed to create the textures.
Building the Concrete Forms
Constructing sturdy melamine forms ensures your concrete keeps its shape while curing. Follow these steps:
Cut Boards to Size
Cut 3/4” melamine-coated boards to size according to your measured dimensions using a circular saw with a fine-tooth blade.
Assemble Mold Box
Screw boards together to create the sides and base of the mold box, with open top and ends. Seal edges with caulk.
Attach Reinforcing Structure
Screw 2×4 studs horizontally to the underside as reinforcement. Vertical studs work for narrow sections.
Create Side Forms
Cut side boards and screw them to the ends of the box. They should be the planned countertop thickness (typically 1-1/4”).
Add Support Brackets
Attach scrap boards as support brackets underneath where joints or overhangs will be.
Seal Mold
Seal all joints and screw holes with caulk. Then coat the mold with multiple layers of paste wax to act as a release agent.
Mixing and Pouring the Concrete
Combining the concrete properly results in an ideal texture and appearance in the finished counter:
Gather Materials
Have the mixed concrete, aggregates, colors, and tools ready before mixing. Gather backer boards and saw horses to support the mold.
Mix Concrete
Pour the concrete mix into a wheelbarrow or large tub. Follow package directions, using the correct water ratio for the right consistency. Mix thoroughly with a hoe.
Add Color and Aggregates
If using integral color, add liquid or powder dye to the dry mix as directed first. Then add water. For exposed aggregate, stir in pebbles last.
Pour Concrete
Place mold on saw horses or supports. Start pouring concrete at one end. Spread it around with a trowel or board. Tap mold to remove air pockets.
Compact and Level Surface
Work back and forth with a straight board to compact and level the concrete’s surface. Add more concrete as needed to fill voids.
Optional: Press Textures
Press rollers, stamps, or brushes into the wet concrete to imprint patterns. Ensure consistency across the surface.
Finish Edges
Use a small trowel to finish visible front edges and create smooth beveled or rounded profiles.
Cover and Cure
Cover the filled mold with plastic wrap. Let concrete cure undisturbed for 2-3 days before unmolding.
Unmolding and Finishing the Concrete
After initial curing, you can demold then finish the concrete using these steps:
Unwrap and Unmold
Carefully cut away plastic wrap and pry off side forms. The countertop should release easily if waxed properly.
Inspect and Patch
Look for any air pockets or holes, especially near edges. Fill with patching compound, matching the concrete color.
Sand Surface
Use a random orbital sander with 50-80 grit pads to smooth away rough spots. Take care near edges.
Clean and Seal
Wipe away all dust. Apply penetrating or topical sealers with a paint roller, following product directions.
Polish Concrete
For a glossy look, use increasingly finer grit diamond pads (200, 400, 800, 1500) on a variable speed polisher.
Apply Finish Coating
Optional finishes like food-safe wax or urethane add more protection and sheen. Use an applicator pad and thin coats.
Install Counters
Have helpers lift countertops in place. Set them on cabinets, shim any gaps, then seal perimeter edges with caulk.
Tips for Successful Concrete Countertops
Keep these tips in mind as you construct and install concrete counters:
- Make molds using rigid, non-porous materials like melamine or plastic laminate.
- Counters should have consistent thickness, around 1-1/4” minimum.
- Reinforce corners and overhangs with rebar, mesh, or fibers for added strength.
- Cure concrete slowly, keeping it damp and protected from sun for 2-4 days.
- Avoid overly dark concrete mixes as they show imperfections more. White cement makes decorative aggregates pop.
- Take time sanding concrete thoroughly to 400-800 grit for a smooth polished finish.
- Use specialty densifying treatments or sealers made for concrete counters that are non-toxic when cured.
- Consider premade countertop mixes that are fiber reinforced and cure quickly for less cracking.
- Expect some variation in concrete counters since they are handmade. The small quirks add character.
FAQs About Concrete Countertops
Get answers to common questions about living with and caring for concrete counters:
Are concrete counters durable?
Yes, concrete is remarkably strong and stands up well to daily wear and tear. Properly sealed and treated, concrete counters can outlast natural stone or quartz.
Do concrete counters stain easily?
When sealed properly, concrete resists stains from spills greatly. Applying sealers annually renews protection. Prompt cleanup also helps prevent stains.
How do you clean concrete counters?
For routine cleaning, use mild soap and water or vinegar-based cleaners. Avoid abrasive cleaners or anything acidic. Reseal annually or as directed.
Can you set hot pans on concrete counters?
It’s best to avoid placing extremely hot items directly on the surface. Use trivets or hot pads, as rapid temperature changes can damage concrete.
How thick should concrete counters be?
A standard thickness is around 1-1/4”. But edges and overhangs should be thicker (1-1/2” to 2”) to prevent cracking from excessive loading or impact.
Can concrete counters be repaired?
Minor damage like chips or cracks can often be patched by a pro using coloring compounds and epoxy filler. Larger repairs may require removing and replacing whole sections.
Do concrete counters need to be sealed?
Sealing is highly recommended to prevent stains and moisture absorption. Penetrating sealers are best for durability. Reapply sealers yearly as directed.
Conclusion
Installing custom concrete counters creates a stylish, durable, and eco-friendly focal point for any kitchen or bathroom. With attentive planning, proper materials, and careful finishing, you can achieve stunning, unique concrete counters that will last for decades. While concrete requires labor and patience, the artistic results and everlasting quality make do-it-yourself concrete counters a rewarding upgrade well worth the effort.
