Learn how to make concrete countertops with the most popular casting method – Precast. For the price of off-the-shelf materials, you can have a one-of-a-kind concrete countertop. Precasting a concrete countertop requires fine carpentry skills and elementary knowledge concrete. This guide walks you through building a form out of 3/4″ melamine and using Sakrete 5000 Plus bagged concrete along with CHENG’s Pro-Formula Concrete Countertop Mix to create professional grade concrete countertops.
Every countertop project begins with an accurate template. Detailed notations, measurements, and planning will help your project flow as smoothly as possible.
Projects destined for the polishing process are typically cast on melamine-coated particle board, an inexpensive, and readily available choice.
Keep your costs low with Sakrete 5000 Plus concrete from your local home improvement center and CHENG Pro-Formula Concrete Countertop Mix.
The concrete mix used in this pour was low-slump and required heavy-duty vibration. Add more water to your mix if you don’t have table vibrators like these.
After 5 days in the mold it’s time to remove the countertop but since the concrete is still young extra care must be taken to avoid problems.
Wet-polish with coarse diamond polishing pads that expose aggregate by cutting deep into the concrete, or use a finer pad for a more uniform finish.
A good sealer is the best way to protect your countertop from unwanted signs of use and wear. Acidic foods like citrus and mustard will even etch concrete.
Waxing a concrete countertop protects the sealer from the wear and abrasion of daily use. Pots and pans can take a toll, so wax regularly.
Homemade Concrete Countertops – The Method
Our completed homemade concrete countertops.
There are two choices when it comes creating homemade concrete countertops. You can pour them in place, or pour separately, and then set in place. There are pros and cons to both methods.
Creating one in place requires building a form directly on top of the cabinets or structure the countertop will be covering. The advantage of building in place is you eliminate moving a heavy countertop once poured.
The disadvantage – it can be difficult to create the form depending on what you are placing it on.
Building separately makes it easy to pour and finish in an open area, but then there is the problem of moving it in place. We have done both methods, and both have worked. But of the two, I can say we prefer building in place. It is nice when you are all done and not have to worry about finding a crew of people to move the heavy slab!
Step 1. : Creating The Concrete Form
Once you decide whether to build in place or separate, it’s time to build the concrete form. We used 2 x 4’s for our exterior counterops, We ran them through the table saw to create 2 x 3’s, and then built the form from there. The 3″ thickness is perfect for standing to the outdoor elements. Anything less, and you risk cracking, anything more, and it is simply too heavy.
We started by placing 3/4″ plywood on top of the outdoor kitchen area, and then screwed the 2 x 3’s in from the bottom. We also created a cutout where our built-in gas grill would go. The nice thing when working with concrete is you can create any shape or cut-out by simply building it into the form. We used additional screws to secure our 2 x 3’s to each other. It is important to use screws as nails can pop out easily from the pressure of the concrete.
Once we had the form in place, we sealed the edges of the board and 2 x 3’s with silicone caulking to keep everything in the form.
Mixing, Pouring And Leveling
Wire mesh or metal fencing placed in the middle of the pour adds strength
It is important to use a high-strength concrete mix for long-term durability. We used 80 pound bags of Quickcrete 5000 series concrete mix for our projects. We then added fiber reinforcement as we mixed the bags at a rate of 2 cups of fiber per bag.
This helps to lessen the chance of cracking. You can also purchase the bagged mix with the fibers already in the mix. You can also mix in colorants to create all kinds of looks. When you add colorants, remember they are liquids, so they will change how much water you need to create the mix.
We used a concrete tub to mix two bags at a time and pour into the form. The key in mixing is to add a little water at a time, until the mix is about the consistency of soft peanut butter.
Our first outdoor concrete countertop project was at the barn.
If you mix too much water, it can lessen the strength of the concrete. It can vary, but we used about 3 quarts of water per bag.
Once mixed, we lifted the tub with the help of a few people into the form and spread it out. It is important at this point to work the concrete down into all of the corners. Once the form was half filled, we pressed in metal fencing to act as rebar. We cut the fencing to fit, leaving about and inch from the edge of all sides and corners.
We then continued mixing and pouring until the form was filled. Concrete is self-leveling by nature, so once the form was filled, we troweled it until smooth. We used a hammer to softly tap the edges of the form. This allowed any concrete voids that may have formed to fill. One final trowel and the pour was complete. We used a total of 15 bags for an 11 x 32″ wide counter. At $5 per bag- that is a pretty inexpensive countertop!
Finishing – Sanding And Sealing
We left our wood forms in place for two days, and then unscrewed and removed them. The concrete is hard at this point, but can still be smoothed out with the use of a grinder. We used an angle grinder and went over the entire surface to smooth over the corners. It is a dusty process, so wear a mask! We watered down the surface prior to sanding to cut down on the dust.
After the concrete had cured for a few weeks, we used a water-based acrylic sealer to give it a glossy look. We never have food directly prepared on the surface, so the sealer is safe to use.
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Should I polish or sand concrete counters?
If you want to see the aggregate in the concrete counters then you'll want to polish the concrete. Polishing will expose the rock or items embedded in the concrete because it grinds off the cream surface. You'll need to polish the concrete if you want to expose crushed glass. Sanding counters will give you a finish with the natural creamy look of the concrete. You won't expose the aggregate with a 200 grit pad and it is much quicker and in my opinion easier to get a nice looking finish by a beginner.
With wet polishing, you can get a higher gloss finish and can bevel edges etc with ease. I wanted to show the wet polishing process in this video, but I've had great results with sanding using an orbital sander. In fact, I recently did a set of outdoor concrete counters using the orbital sander method and and was thrilled with the results.
How Much Does it Cost to Make Your Own Concrete Countertops
So now you’re probably wondering “how much does it cost to make you own concrete countertops IN TOTAL, not just material!?!”
I hate to say it but it it really depends. It depends on which concrete countertop mix you go with, how many tools you already have lying around and what forms you go with. On average, I’d say the average DIYer either has or could borrow from a fellow DIYer, most of the tools they need. A person with about 30 sqft of kitchen counters would probably be spending between $400 and $700… that’s nearly the same price as laminate!!
As some of you might know, we did concrete counters in the kitchen of our apartment remodel and even the bathroom countertop!! I wound up staining the concrete countertop in the bathroom to try and match the shower tile. You can judge for yourself in the picture below if I did a good job or not. I personally like the way it came out but it doesn’t exactly match the tile in the shower. We also did a faux rock edge on both concrete countertops and I LOVE the way that came out.
I hope this post answered the question “how much does it cost to make your own concrete countertops?” I truly believe doing your own concrete counters is an easy-ish way to update a kitchen on a budget, while not looking like you used budget countertop material. Does that make sense?
My only suggestion before attempting DIY concrete countertops is to do some research beforehand and also to make a small “practice” countertop before you do the real thing. If you do decide to DIY a concrete countertop, I’d love to see it! Find me on social me @thestoneheaddiy!