Our Best Concrete Countertop Tips
Whether it’s for a kitchen or bathroom, countertops can be one of the most expensive materials in any renovation. While researching low cost countertop options we came across tons of photos of beautiful kitchens and bathrooms with concrete countertops. Having some experience pouring concrete I thought, how hard could making our own concrete countertops be? I spent weeks researching and subsequently falling down the rabbit hole of special additives, complicated ratios, and very expensive premixed solutions. There are some very skilled concrete countertop makers on YouTube, but for those who just want to create a good looking, functional, countertop without breaking the bank, it can be overwhelming. In the hopes of you not making the same mistakes as us, we’ve compiled the biggest concrete countertop tips in one place.
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You don’t need to be a rocket surgeon
While researching concrete countertop tips, there were several companies that had their own proprietary formulas for turning a $10 bag of concrete into a $1500 project. From spraying a face coat of portland cement onto the forms prior to pouring, to spending hundreds of dollars on additives, the process seemed more complicated than it needed to be. Instead of buying hundreds of dollars’ worth of special tools and mixes, we decided to just experiment. If the first attempt didn’t work, we would only be out $150 for the concrete.
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Which mix?
Our first attempt at concrete countertops was successful; we achieved the look we wanted, it was very affordable, and it wasn’t an extremely difficult process. Although it wasn’t a difficult project, having the right ready-mix makes the task much easier. We found that Menards sells a product called Premium Concrete Countertop Mix which is a polymer modified, glass fiber reinforced (GFRC), mix that will be our go-to in the future.
The advantage of using a glass fiber reinforced mix is that the aggregate is a lot smaller (not as heavy) as the rock that is found in the traditional Quikrete. A polymer modification allows for flexibility when normal concrete would crack. The combination of the polymer modification and the fiberglass strands results in a very strong, lightweight, crack-resistant countertop. It took us a while to find this product and is one of the concrete countertop tips that will save us the most time in the future.
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Thickness
Prior to our first countertop project, several articles I read mentioned a minimum thickness of two inches when using a normal concrete bag mix. I don’t know if you’ve ever carried two-inch-thick concrete countertops, but that amount of weight is almost unmanageable. This is also why we will be using polymer modified GFRC mixes in the future. By using fiberglass strands instead of rock and adding a polymer additive we were able to create a one-inch thick continuous countertop in our master bathroom. We would not have been able to carry the nearly eight-foot-long countertop if it were made with a traditional bag mix.
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Water content
When mixing concrete, or any mixture that contains Portland cement, adding too much water can potentially ruin the entire batch. Floating the bottom of the countertops after your forms have been filled will bring much of the water to the surface and you’ll have to screed off that water, so it doesn’t sit. We still had water sitting when we left it to cure and that created a couple problems. First, the spots on the bottom of the countertop where water had pooled created pieces that easily flaked off. Second, when pieces flaked off it created an uneven surface on the bottom of the countertops. While this didn’t affect our project, it could have caused problems if we had to adhere an under-mounted sink.
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Vibrating
Air bubbles in concrete create a multitude of problems, and when on a countertop’s surface they can pose a health hazard. Air bubbles will create tiny holes on the top of the countertop that can harbor bacteria. We used a random orbital sander to vibrate all the tiny bubbles and bring them away from the top of the countertop. The problem is that it can be hard tell when you have vibrated the concrete enough. Our new rule of thumb is to vibrate for five to ten minutes after we don’t see any more air bubbles rise to top of the form (bottom of the countertops).
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Sealer-Related Concrete Countertop Tips
The right sealer is crucial, making this our most important concrete countertop tip. Cheap sealers, even with multiple coats, will allow water to reach the concrete and stain the surface. Unfortunately, there aren’t many different concrete sealers out there, not to mentions ones that are food safe for kitchen countertops. We scoured the internet and found the ChrislovesJulia blog post “Sealing Our White Concrete Countertops” where they used a product called Stonelok E3/2K2 from V-Seal. This stuff is amazing; it is food safe, abrasion resistant, heat resistant, and you can clean it with your normal household cleaners.
If you’re like us and you’ve seen the $20 bottle of concrete sealer at Home Depot, you might be a little surprised at the cost for the smallest kit of Stonelok. At $140 for just 40 square feet of coverage it wasn’t easy for us to justify the purchase, but 2 years after the first application we still have nothing bad to say about the sealer. We put hot pans directly on the countertops, we spray them with Lysol; this sealer performs phenomenally. In contrast we used a very cheap sealer on our bathroom countertops and condensation from glasses of water have stained the concrete. If you want to protect the investment of your time and money, use a good sealer.
These are just a few of the lessons we learned the hard way. As with any project they are the most valuable lessons that will only make us better in the future. You can find more pictures of our concrete countertops on our Instagram! What are your experiences with these concrete countertop tips?
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Disclaimer: We’re not professionals or experts on this topic, so all we can do is share our own personal experience in hopes that it helps you in your journey! We always recommend consulting with the pros directly.