DIY Concrete Countertops
This guide will provide you with the knowledge to make your first successful do-it-yourself concrete countertop. Avoid common mistakes, and create the countertop of your dreams.
This guide will provide you with the knowledge to make your first successful do-it-yourself concrete countertop. Avoid common mistakes, and create the countertop of your dreams.
Hi, I’m Jeff Girard. I built my first concrete countertop in 1999. Back then, I didn’t have a guide to follow, or have beautiful step by step DIY concrete countertop instructions like you have here.
However, what I did have was a civil engineering degree, and a passion to create something beautiful for my kitchen. I made a lot of mistakes along the way, but had you asked me if I would go on to create The Concrete Countertop Institute, and train thousands of contractors along the way, I would not have believed you.
The technique that I used back then, and that I will explain on the remainder of this page, is precast concrete countertops. This is a traditional, basic way to make concrete. The overall process is:
The concrete is made 1.5″ thick and weighs about 18 pounds per square foot. An 8 foot long kitchen countertop slab would weigh about 300 pounds.
Before I go any further, I should tell you: There is actually a brand new, extremely simple and easy way to create concrete countertops! Simply apply thin layers of a specialized micro-concrete to existing laminate countertops, like frosting a cake!
The weight of the concrete with this technique is about 1/3 pound per square foot, or about 1/50th the weight of precast concrete! The technique uses simple household tools such as a cake mixer and silicone spatula. The countertops are lightly dry sanded by hand, producing very little dust.
You can even do this with plywood countertops instead of laminate. It might be easier to build plywood countertops on top of your cabinets and then coat them with concrete.
If you decide to investigate this technique, please see Finale DIY Concrete Countertop System.
Otherwise, continue reading this page.
The aim of the following Precast DIY concrete countertop guide is to provide you with a solid foundation in concrete countertops, and to help you navigate through the most common problems you may face along the way.
I hope you are as inspired as I am in turning such an industrial material like concrete into something beautiful for your kitchen, bathroom, or any countertop project.
PS – If you prefer video training, please check out my FREE online seminar Precast DIY Concrete Countertops with Mix Design.
In this chapter we will cover basic safety guidelines and tools you need to create your very own concrete countertop.
First we will cover how to be safe, and then we will talk about the basic tools you will need.
Before you begin any DIY concrete countertop project, it’s important to think about safety.
The most common tools you will need to begin your diy concrete countertop tools are the following –
To build a precast concrete countertop, you will need some basic tools, materials, and plan for safety. Please refer to the list above before beginning your project.
Chapter 2 is all about setting up your workspace environment to make your precast concrete countertop.
If you are a DIYer, a common garage will do just fine.
To build your precast DIY concrete countertop, any open space in your garage or basement will be just fine. You will want to use this space for a few days, so alert anyone in your house on your upcoming plans.
You don’t need a specialized space to build a precast concrete countertop. In fact, anyone can build a concrete countertop in a garage or available basement. Just keep in mind, you will need to move your finished precast countertop, so measure any tight spaces, corners, or doors before you begin.
In this chapter we will learn how to build your concrete countertop template.
Taking the right measurements here, will lead to a more accurate fit! So measure twice!
Templating for concrete countertops starts with creating a physical mockup of your current countertop space. Good and accurate templates ensure an accurate fit, and gives you the dimensions you will use in Chapter 4 called Forming.
Templating is also the time to locate sinks, fixtures, and any concrete overhangs you will have. And it is also a good time to double check your site conditions (like stairs, doorways, tight spaces.)
By now you should have a physical template of your concrete countertop. You will use this template to move onto the next phase of this process, called forming. Here, we will break out the power tools and begin constructing the concrete countertop form. This is the fun part!
Forming is the process of making the actual mold to pour the concrete into. Making sure your form, follows the exact dimensions of your template is very important!
Forming is the process of creating a mold out of materials (usually melamine) so that we can pour concrete into a form and let this concrete cure to the proper shape.
Forms must be made from materials that are smooth, dimensionally stable, straight (unless you build out a curve), and non-reactive and non-staining. Wood, steel, particle board and rigid foam can all be used, but we prefer to use melamine.
Melamine is often found at your local Home Depot® or Lowes® and is cheap, smooth, and won’t react with your concrete. It is a manufactured wood, with a smooth melamine surface.
Purchase the largest melamine sheet for your project. You will be taking this sheet home and making the necessary cuts for the sides, countertop base, and any cutouts for a sink or fixtures.
Once you have your melamine pieces, it is time to build out your form. One of the easiest ways is to lay out your base melamine sheet on a flat surface. Take your template and lay it on top of your melamine base. Now start constructing the sides making sure that the template sits flush around the edges.
The easiest way to form the sink knockout is with a piece of foam, or with melamine strips cut to size. This is a good time to grab your sink template and use it as your guide.
Forming your faucet knockout for your concrete form is slightly different. With faucet knockouts we recommend using a circular mold for your faucet holes. However, you absolutely need to have the faucet before you build your form. Every faucet is different, so don’t guess!
Caulking is not used to waterproof your forms. It is used to save a lot of time, as your concrete countertop edges will be true. If you do not use silicone in your form, you would need to grind and sand your concrete countertop once it has been cured and pulled out of the form.
Here is what you have done so far. You have used your template created in Chapter 4 to build your melamine base to size. You then used this template and constructed your melamine form.
Both your sink and faucet knockouts were added to the melamine form. The last stage of the process requires you to apply an even bead of 100% silicone to maintain uniform edges and save you a ton of time!
In this Chapter we will learn why reinforcing concrete countertops are critical to your success, especially with precast DIY concrete countertops.
Proper concrete countertop reinforcing is critical to your success. Without reinforcement, your concrete countertop may suffer from cracks or damage during installation, or even show signs of damage over time.
Keep in mind that precast concrete countertops need to be moved for installation, and therefore it is a good idea to provide at least some form of reinforcement.
To understand proper concrete countertop reinforcement, you first have to understand that a concrete countertop is never reinforced like a sidewalk or driveway. That is because a concrete countertop is actually a beam.
When a beam has weight placed on top of it, that weight causes the beam to deflect (bend). Small weights on stiff beams cause almost no deflection, while large weights on flexible beams cause significant deflection. Concrete countertop slabs will flex and bend from their own weight when they are stored, handled and moved horizontally. This often occurs at various times during processing, transportation, and installation.
The deflection in the concrete countertop causes two things to happen: The top surface is compressed and tries to get shorter, and the bottom surface is in tension and tries to get longer. The more a beam deflects the greater the stresses develop in the beam.
Compression is the opposite of tension, so as one progresses down the concrete countertop, the compression stress gradually decreases to zero and then the stresses reverse, go into tension and gradually increase towards the bottom of the beam.
This is why you never want to reinforce a concrete countertop in the middle where the compression is minimal.
Masonry block ladder wire reinforcement is a very versatile form of reinforcement. This form of reinforcing is used for constructing masonry block walls. The preferred wire is 9 gauge or 0.147″ (3.7mm) in diameter.
Do not use reinforcing greater than 3/16″ (4.8mm) diameter for concrete that is less than 3″ (75mm) thick.
Stucco mesh wire, and galvanized fencing is not recommended for reinforcement. In addition, rebar of any size, or fiberglass (GFRC is the exception) is typically not suitable for reinforcement.
There are two locations where reinforcement is located within a concrete slab. Primary reinforcement is always located on the underside of the concrete countertop. This reinforcement resists the tension forces developed when the slab is handled and installed with the finished side up. Cantilever reinforcement is located near the top, or finished surface of the slab. It resists tension forces that develop on the finished side of the countertop.
Here’s the fun part! We have built our concrete form and are now ready to pour concrete. Before we do, we have to understand a few things about how concrete works!
With proper planning anyone can mix beautiful concrete for your countertops. However, if you miss a few steps, or add too much water, your countertop may not turn out as expected. Follow these tips and you will be on your way.
This formula is based on local raw ingredients and is great for any DIY concrete countertop enthusiast. It is also strong and reaches 5,000 psi in 3 days.
Makes about 8 sq. ft @ 1.5″ thick for a concrete top
Pozzolan is an admixture for concrete that replaces part of the cement and improves the strength of the concrete, enhances workability, and boosts long term strength. The pozzolan VCAS is an ultra fine ground glass. If you cannot get VCAS, just skip it and use cement instead.
Superplasticizer is a type of concrete admixture called a water reducer. Water reducers make concrete more fluid without adding more water to the mix (which would weaken it).
“Superplasticizer” is another name for “high range water reducers” that use polycarboxylate chemistry. ADVA Cast 555 is one example of a superplasticizer.
The mix design above has a water/cement ratio of 0.32, which will result in a very high strength mix. However, the mix might be very stiff and difficult or impossible to mix and pour.
Adding 2.5 lbs more water would result in a w/c ratio of 0.40, which greatly reduces the mix strength. Instead, it is preferable to add a water reducer. This will make the concrete more flowable and easier to work with without compromising strength.
If you cannot find a superplasticizer, you may add more water slowly, up to 2.5 lbs more. It is important to keep track of exactly how much additional water you add so that all batches can be consistent.
Now we are ready to pour your concrete mix into your form, and create a DIY concrete countertop. By now you have put it a lot of work and understanding.
It’s time to have fun and cast your concrete countertop, let it cure, and get ready for the installation.
Casting is the process of pouring your concrete countertop mix into your form. This is the final step before you see your finished product.
Processing and grouting is when we get to remove the concrete countertop from the mold, and begin to prepare the piece for installation.
The main steps in processing are flattening, grinding, honing and grouting.
The first step of processing is to ensure the underside of the slab is flat, at least around the edges. There should be no high spots anywhere.
The screeding that you did in Chapter 7 Casting, should have established the correct slab thickness. If you did not take care in this step, it may be necessary to do some hard work to remove hard concrete using a masonry rub brick.
Some grinding with a diamond pad may be necessary to ensure adequate flatness.
If you want to expose aggregate, or you have embedments in your concrete, then grinding is a necessary step. Grinding uses coarse, aggressive diamond tooling to remove a lot of material fast. To do this, you need a professional grade electric polisher such as the Flex LE12-3-100, which is available on Amazon, as well as diamond pads in grits 50, 100 and 200.
When your concrete countertop is removed from the form, it will have a cement skin that needs to be removed. This skin is very vulnerable to scratches and damage.
In addition, if your forms were coated with a form release agent, the release agent’s residue must be honed off. Honing is the next step after grinding or flattening.
Honing removes any marks and flattens and smooths the surface. Honing can be done by hand with diamond hand pads.
Grinding and honing reveal voids, air bubbles and fissures within the concrete. These must all be completely filled with tinted cement grout before sealing. In most cases, the grout will be the same color, or a very similar color as the base concrete.
It’s difficult to get an exact match, and often it’s not necessary. Contrast between the grout and the concrete, slight or otherwise, is often seen as attractive and desirable by many clients.
Grout = Cement + VCAS + Pigments + Polymer
This is it, you made it to the end. It’s time to seal your concrete countertop and get ready to install your piece.
Sealing is perhaps one of the most important steps as it protects your countertop from staining, and residue from everyday use.
You now have a beautiful piece of bare concrete, that is smooth, flat, and looks the way you want it. However, to make it last over time, you need to seal your concrete countertop and here’s why:
Concrete countertop sealers can be separated into two basic groups: penetrating treatments and topical coating sealers.
Penetrating treatments are liquids that are applied to bare concrete and soak into the concrete. They work by reacting with the concrete to decrease its porosity and increase the surface density (hardeners/densifiers) or by increasing the surface tension to cause beading (repellants).
They do not block contact with the concrete, but merely make it easier to clean up spills. They don’t provide much if any protection against long-term exposure to aggressive staining agents (like wine, mustard and oil), nor will they provide any protection against acidic items. In fact, acid usually begins to etch the concrete almost immediately.
The advantage of penetrating treatments is that they are extremely easy to apply, and since they soak into the concrete and do not leave any film, they cannot be scratched.
Topical sealers create a physical barrier between concrete and your environment. Concrete sealed with a topical coating cannot stain or etch because the staining agent never touches the concrete. Modern coatings have excellent adhesion, good scratch resistance, and a very natural appearance.
The disadvantage of coatings is that they can scratch.
I am a strong advocate of using coatings to provide the best protection against staining and etching. I’ve always found that people would rather not have to worry about staining and etching (and watermarks – that should never be an issue) than have something they can cut on. Cutting is a deliberate act, whereas spills of lemon juice, red wine, oil, etc. are accidental, or at least could be accidentally forgotten and not wiped up.
Before Ovation, there were simple, easy to use single component concrete countertop sealers available, BUT they were either highly toxic or very low performance. I developed Ovation Concrete Countertop Sealer TM to address these concerns.
Ovation is the first safe, simple, single component concrete countertop sealer that actually performs.
Ovation is water based and completely food safe. The most “toxic” chemical in Ovation is ammonia, which is naturally occurring throughout the environment in the air, soil, and water, and in plants and animals, including humans. Ammonia is also found in many household and industrial cleaners. Once cured, Ovation has no remaining ammonia or ammonia odor.
Ovation provides excellent stain and acid resistance to most substances up to 1 hour of exposure. Simply wipe up spills promptly, and your surface will remain looking great for years.
You can use Ovation anywhere – indoors or outdoors, wet or dry. It has a soft satin sheen and a very natural appearance.
Installing your DIY concrete countertop is no different than installing granite countertops. You want to always carry it on a vertical side like a piece of glass.
It is a good practice to dry fit the countertop slabs prior to gluing them down. Dry fitting provides an opportunity to check the fit and alignment and to find out where shimming is necessary. Dry fit the pieces as if they were going to be permanently installed. Precise seam alignment isn’t necessary at this point, but gross misalignment should be corrected.
When dry fitting is completed and the final installation process is to occur, the slabs are bonded to the cabinets using dabs of construction adhesive. The adhesive serves two important roles: it adheres the concrete countertop to the cabinets so they don’t shift, and the hardened adhesive acts as a grout bed, firmly and evenly supporting the slab.
Now it’s time to get started on your own creative concrete project!
The possibilities of concrete are endless. Check out the DIY success stories below.
“My counter tops turned out pretty great! See photo. Just what I imagined. They are rustic, but that was what we were looking for.
I was flabbergasted at how hard it was to make them. No wonder they cost as much as granite. The materials were relatively cheap like $250+/- here in Denver for everything, but the sheer amount of labor involved was totally unexpected.
Also, they are really f-ing heavy. Holy cow I couldn’t believe how much a slab could weigh. The corner slab weighs almost 400lbs. Yikes.
Thanks for the info it was invaluable and made my first attempt a success….errrr…..I actually made the first ‘L’ mold upside down so when I pulled the mold after three days the counter top was backwards.
This sent me through the roof. I tried to smash the slab with a sledge hammer in frustration, but only hurt my hands as the sledge bounced right off and reverberated up the handle, shaking my bones.
This infuriated me so much I tipped the slab up on end and pushed it out of my garage and succeeded in badly damaging my driveway.
Clearly the formula you provide for making very solid counter tops is correct. I literally could not demo the slab. I couldn’t even crack it ‘throwing’ it around. I was then suddenly very pleased that the next ones would be super strong and do what I needed them to do.
I think they look pretty cool.
They sure do, Willis! Great job!
Willis used the “How to Make a DIY Concrete Countertop” online video training to make his unbreakable countertop.
This online video training goes far beyond the information provided on this page and includes:
– Over 7.5 hours of detailed, live-action videos explaining every step!!!
– A 3-hour seminar explaining how to get started with concrete countertops.
– A 67-page step by step textbook
This unique online course includes extensive live action video. I will be with you every step of the way guiding you, showing you what to do next, and revealing the advanced “insider secrets” to give you a fulfilling result.
I hope you’ll consider taking the next step towards making your DIY concrete project a reality by checking out the How to Make a DIY Concrete Countertop online video training.
Here are some more examples of projects that DIY students have made:
However you choose to continue your concrete countertop learning, whether it’s with the How to Make a DIY Concrete Countertop or not, I look forward to helping you as you discover the endless possibilities of concrete.