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It’s been right at 4 weeks since we’ve started our kitchen renovation and I’m so excited to share all the steps I took to create beautiful white concrete countertops! I typically dive into a project with proper research and a good attitude knowing that most things are “fixable”. However, there were quite a few uncertainties I had going into this – mainly because it is a more permanent project… and this was the FIRST time I have ever poured concrete. My goal for this post is to take those uncertainties away if this is a project you plan on doing yourself.
I worked with Z Counterform on this entire project and everything from the product to the customer service was outstanding. I can’t imagine tackling a concrete project without their tools and support. I used their White Concrete Countertop Mix along with the Square Forms – which gives you a modern look and an overall countertop thickness of 2 1/4″ inch. They also offer a variety of other decorative edges depending on your style.
This post is Part 1 of 2 – and will cover all the steps to help you plan, prep and pour your concrete project. Part 2 will cover the sealing and maintenance of concrete countertops.
It should be no surprise that prep plays a crucial role in this project. Be prepared to spend a day getting everything ready for your pour.
THE FOUNDATION/SUBSTRATE: The first step is to lay down your substrate. Z Counterform recommends durock or HardieBacker cement board. An important thing to know here is that the size of your substrate is very important – especially if you are using IKEA cabinets. The total depth needs to be as close to 5/8″ inch as possible while not being under. This is important because if you are under, your countertop will hang too low and not allow you to open your cabinet doors. If you are too much over, you will end up seeing the plywood from underneath after the pour. I ended up using 1/4″ (.28) plywood with 1/2″ (.42) HardieBacker board on top. What I didn’t anticipate was that the steel supports on IKEA cabinets adds almost another 1/8″ on top of your cabinets. If I had to do it over again, I would choose thinner plywood. (Make sure and get exact measurements of your materials – the descriptions are rarely accurate.)
Note: It is worth mentioning that if you are not using IKEA cabinets,the use of 1/2″ HardieBacker would be fine in almost all cases. The only time the thickness of the substrate needs to be so closely monitored is when your drawers sit flush with the top of the cabinet.
I used a jigsaw to cut both materials, but used a diamond blade when cutting the cement board.
Finishing nails can be used to attach the plywood to the cabinets – then a simple construction adhesive to attach the cement board to the plywood. The plywood and HardieBacker were cut flush to the cabinet edge anywhere I was using the square form. The forms will end up giving you a 1.5″ overhang. If you have an edge where you do not want an overhang (stove area), you will want to leave about 1/2″ of a gap so that the concrete fills this area and you don’t see the plywood once the form is snapped off. This edge can be secured with a simple 1×6 or straight board secured to your cabinet.
I am using an under-mount apron front sink in our renovation and could not find any detailed information on how to prep for this type of sink. I called Z Counterform for help with this (they have all the answers) – and found out I could do a slide in sink installation – meaning I could slide in the sink after the countertop pour was completely finished. I dry fitted the sink to determine where to cut the plywood base – confirming that the concrete would be almost flush with the inside edge of the sink. I used the knockouts that Z Counterform carries for both my faucet and my soap dispenser. I used a 2 5/8″ hole saw to cut through both layers. I also put coconut oil on the knockouts before installing them – which I would recommend in helping them come out smoothly as they are a very tight fit!
After installing the substrate, it was time to install the forms. Most corners were very easy to install with simple miter cuts using a miter saw. This applied to both inside and outside corners. If you want a detailed look at all the different corners involved, I put together a quick video.
I secured the forms with #10 5/8″ pan head screws. It wasn’t necessary to pre-drill but I did to ensure the forms didn’t split. You will have slight holes/gaps on all the corners. Make sure and take EXTRA time and then go back and take more time to ensure that you tape up or caulk anywhere that liquid could escape (think corners – but also the underside of cabinet anywhere you used a flush form). The important thing here is to not tape on the inside edges of the forms, as that would show once you removed the forms.
The next step was securing the fiberglass mesh. This was the simplest and most straightforward process. I used the standard Z clips provided by Z Counterform and secured them every 6-8″ with the same #10 5/8″ screws. DO NOT SKIP THIS STEP. This is what gives the concrete structure and protects it from cracks.
Okay… almost done! The last step in prep is to protect your cabinets and floors with some plastic tarps. Things get messy folks. I did not tape down my plastic as securely as I should have… take note – tape every seam and corner unless you want to spend extra time cleaning up after.
A few things to make mention before I get into the pouring process. You will want to use a powerful corded drill. Cordless drills will not work for this. I used this drill and it was great. (I actually started with a different electric drill and it burned out on bag 3! ) A couple of people have mentioned renting a concrete mixer, but the staff at Z Counterform advised me against this.
I used the Bright White pigment packs to get an extra white finish. When using this pigment, it is very important to keep with the same water ratio as the amount of water does affect the color. The amount of water that worked for me was the recommended amount of 3 QT per 50 lb bag of concrete. I started with 2 QT – adding 1/2 QT after about 1/2 – 2/3 of the bag was mixed and then another 1/2 QT at the end. It’s important to add the concrete slowly and allow it to mix properly to not overload your drill.
For my counters, I had about 28 sq ft and ended up using right under 10 bags. I had 3 people assisting which is something I would highly recommend. 1 or 2 of us could be mixing while the other worked on leveling the pour.
We worked together to pour the concrete – starting at one end and working our way down in one direction. You will want to use a very firm straight edge to screed the concrete mixture smooth and level as you go – ensuring there are no low spots. If there is light between the screed and the mixture, you can take a small trowel to fill in the mix and then re-screed. Keeping a wet edge, keep screeding until you get to the edge of your counter. This will seem overwhelming at first, but it will make sense as you go and the mixture fills in nicely.
It took about 45-60 minutes for the mixture to set up so that I could use the magnesium float to start smoothing out the mixture. This is where the magic starts to happen! Apply just a small amount of pressure and work in arcs in various directions, trying to smooth things out as much as possible. The concrete should be firm at this point – not moveable – but you should be able to smooth it out easily.
Below is a short video on mixing, pouring and floating the cement mixture.
The last and final step is using your steel trowel – and also where you will get your silky smooth finish. We waited for about 3-4 hours but it will depend on your environment. You will know it’s ready if you have to press firmly to show a fingerprint. It’s important here to start on an edge and keep your trowel on an angle to keep any trowel marks from showing. I used an average amount of pressure and went in multiple directions until I was happy with the finish. If you have any blemishes at this point, it’s important to know that you will be able to sand them out after the concrete dries… so don’t worry about getting it PERFECT.
I waited about 48 hours to remove the forms. It was the most satisfying feeling ever! I sanded the edges of the forms so the excess concrete was gone before trying to separate the form… and then with a little bit of effort, they magically snapped off!
I am going to let them cure for 10 days before I seal them so I still have a few days to wait. The biggest question I have been getting over on the gram is “Will they be durable? What about stains?” Sealing is what is going to give you the durable surface that all of us want in a countertop – so stay tuned for those details!
Here’s a complete list of all the materials you will need on hand to to create your own concrete countertops.
Here is a cost breakdown of what you can expect to spend for a 30 sq ft area:
White Concrete Countertop Mix (10 bags): $290
Bright White Pigment Packs (10): $60
Square Edge Countertop Forms: $139
Accessories (Z Clips, Faucet Knockout, Mesh): $85
Plywood & HardieBacker: $90
Supplies (screws, trowels, paddle mixer): $100
Total Cost: $813
Okay so that covers Part 1! Make sure and leave any questions you have in the comments and I will answer them in a Q&A follow up post! Stay tuned for next week when I share all the details on sealing and maintenance for these white concrete countertops.
If you’re ready to create a home you love with your own two hands, I’m your girl.
© 2021 Making Pretty Spaces
Wife, Mama, Renovator, DIY Educator, and Founder of Making Pretty Spaces. If you’re ready to create a home you love with your own two hands, I’m your girl.