Preparing the Workspace & Surface
This is an overview of the steps we took in order to prep our workspace and also the steps of preparing the counter for pouring concrete. The preparation is just as, if not more, important than the “fun” part of pouring the concrete. So roll up your sleeves and let’s get to work!…
Remove everything out of your kitchen except for maybe the kitchen table to use as a work surface. Empty out (ALL) your cabinets, pantry, etc. Remove all curtains and blinds. We’re talking bare bones here… We also took out the drawers of our cabinets and set them aside. Unplug and pull out any appliances (oven, dishwasher, etc.) that sit next to the counter tops (Use caution when working with your appliances. Make sure your electricity is turned off to those units before moving and refer to your user manuals for the proper way to unplug them! If you’re not sure call and ask an electrician!). We left our fridge plugged in, but we pulled it away from the counter so we had room to work. You will also need to remove your sink!
Is your kitchen totally and completely empty? Good, let’s move on!
Maizey wondering what in the heck is going on?
Here comes the fun part!
Rip out old cabinet tops. We were lucky and had laminate so that’s fairly easy to remove. Just do whatever it is you have to do to get your current counters out of the house.
Note… we saved our old countertops just in case this project was a complete and total fail. In the end it was a success and we eventually hauled it off to the dump… but we held onto them juuuuust incase we had to reinstall them.
*** IMPORTANT: You need to take into account your sink’s dimensions when starting to prepare your cabinet boxes – and with every step from there on out. You need to double, triple, quadruple check each step if you want your sink to fit when you’re done!!! We purchased a new sink and had a template to work with! ***
Lee pointed out while trying his best to proof read my mumbo jumbo that the tool second to the right is actually a tool for the car… Whatever man! I use anything that will get the job done! …just don’t tell him I didn’t end up using it. 😉
I scored the silicone caulk so the backsplash was easier to remove.
I had to hammer the crow bar in-between the wall and backsplash in certain places.
I used drywall putty to fill in the gaps, and a razor to remove high points, so that the wall on the backsplash was even. If you are going to reuse your sink this is a great time to get all of the measurements so you know *exactly* how big and where to recreate the same opening.
Build braces into your existing lower cabinet boxes with 1x3s (or whatever size you need per your counter measurements and build) to help support the weight of the concrete. There was one area where we didn’t think we needed to brace and the backer board DID bow a bit under the weight of the concrete! So I suggest bracing and reinforcing as much as you can. Refer to the diagram below to see a rough idea of how we installed the braces on each of the top of the cabinet boxes. No such thing as overkill here… This concrete is super heavy; 1 Cubic Foot of Concrete weighs approximately 150 lbs!
Side Note: You obviously don’t want the bracing to interfere with your sink when it’s time to install… so just keep that in mind. It’s really the cabinets that are wider/larger than 24″ that you’ll want to reinforce.
Be sure that the supports are flush against the top/level with the top of the cabinet boxes (so you can evenly lay the concrete backer board on top) and also make sure that they aren’t sticking too deep down into the cabinet box to interfere with the drawers that will go below.
In the larger cabinet boxes we installed two supports for each back corner. FYI – We didn’t find this online. We just went with a pattern and support system that we thought seemed like a good idea.
We also added supports *around* where the kitchen sink would be installed, but not interfere with the sink itself.
A close up of one of the corner supports.
Cut (Lee used a utility knife to deeply score/cut) and install cement backer board onto the cabinet boxes using drywall screws. I then covered all of the screw heads, seams, and any noticeable cracks in the backer board with black silicone caulk (You don’t want the water from the concrete seeping through any holes/cracks into your cabinet boxes below).
Install the countertop forms. We made ours out of a sheet of melamine and it entailed a LOT of planning, measuring, calculating, etc. And it STILL ended up causing issues for us. This is where I say, “If I did this again this is what I’d do differently…” You’ll save yourself a lot of time and effort if you’re able to buy the “snap-away” forms. Our penny-pincher, diy attitude got the best of us here.
If you construct your forms from melamine like we did, make sure you plan and design them so that you can uninstall them when the concrete is dried! (That means making sure the screw heads will be accessible on the *outside of the form* in order to remove them when the concrete is set – DO NOT pour any concrete over the screw heads that are screwed into the melamine!) – At this time you will also need to have whatever sink you will be using on-site and it’s specific dimensions so you can build your forms accordingly.
- Note: One of the most common problems with concrete counters (and concrete in general!) is cracking. Cracking is caused by several things, but is fairly preventable if you take the time to do this project right.
- Cracking can occur if:
- the concrete adheres to the wall (or if it adheres to more than one fixed surface)
- shifting/settling/expanding and shrinking
- adding too much water to the concrete can make it brittle and prone to cracks
- lack of structural reinforcement with internal and external structures
- Each of these potential problems will be addressed as we go through the steps.
- Cracking can occur if:
It’s vitally important that you *really* think through the construction of your forms before moving to the next phase. You need to triple check that you have a deconstruction plan so you can remove the form when the concrete is set. This really takes some forethought – so take your time and demo/walk yourself through the steps of the form removal process once they’re installed!
Put a barrier on the drywall backsplash where the concrete will come into contact. I just simply put long, horizontal strips of clear packing tape on the wall, starting at the base of the cement board up about 6 inches or so. When the project was compelted I used a utility knife to score and removed the excess tape. Some tape was left behind as a barrier between the drywall and concrete! If you purchase the breakaway forms I recommend, they include a strip of form for the backside of the counter that sits against the wall/backsplash so the concrete doesn’t actually come into contact with your walls/backsplash. This is a permanent piece that stays in place when you’re done.
Caulk! This is a very important step (1) because you don’t want the water from the concrete mix seeping through the cracks in forms dripping into your lower cabinets and floor, and (2) the caulk along the corners of the form will help shape of the edges of your finished counter. When you put a bead of caulk here it softens the bottom edge so it isn’t so a sharp 90 angle.
The thicker the bead of caulk, the more rounded the edges will be. Again, if you use the pre-made forms you won’t have to caulk as much. We caulked everywhere because we didn’t want the water runoff from the concrete seeping all over our kitchen.
Once the melamine forms are in place it’s time to install the remesh.
This is another very important step and helps to prevent the concrete from cracking. Just like with every step of this project, there are many ways and ideas floating around out there on how to do things. Some folks have used rebar, some used remesh, some used metal lathe… We decided that the remesh just “made sense” to us so that’s what we went with.
We used drywall screws to create mini “X” shaped stands/supports so the remesh would sit suspended, or floating above the backboard, which was calculated to be about half of the depth of our concrete countertop. The “X”s also helped to hold down the remesh which didn’t want to lay flat on it’s own.
- We saw a tutorial where some folks poured half of the concrete into the forms, then laid down the remesh to float on top of the first half of concrete, and then layered on the top half of the concrete (no screws). But it looked like they struggled because the remesh didn’t lay perfectly flat and trust me, you don’t want to be fighting with wires while you’re dealing with set cement.
The idea is to get the remesh in place and then pour the concrete on top. This was take a little more planning ahead, but is worth it!
These “X” screw supports allowed us to “pinch” around and secure the remesh holding it in place, plus I feel that the screws acted as yet another reinforcement. Having said that…. the more screws that go into the backboard, the more holes! Caulk allllll around those holes.
- This YouTube video shows a different method of internal support (he is using ladder wire) but his concrete mix is a specialty product, so maybe research the different methods and material options. He also uses the fancy schmancy pre-made forms. But bottom line is you want your wire to sit at half the depth of the counters. How you accomplish this is up to you!
By creating these “x” supports with the screws we were able to pinch the remesh into place. This held the remesh flat (because it came in a roll it didn’t want to lay flat on its own) and it also held the remesh suspended to about 1/2 the depth of the finished thickness of the countertop.
Be sure to leave space between the remesh and the edge of your form. You won’t want the metal poking through the edge of your finished countertop! Caulk every single nook and cranny!
Vacuum up any dust on the surface of the backboard and allow the caulk to completely dry. This is also a great time to tape up more plastic sheeting to protect your cabinets. I also taped the plastic sheeting to the floor, creating a walking path from the door and all around the counters. Yes, concrete will drip as you haul it in and pour. Plan accordingly.
Use plastic sheeting and tape to completely seal off any entries that go to the rest of the house. I created a double layer by taping the plastic sheeting to both sides of the doorway. I also created a negative airflow inside the kitchen (by opening windows and using fans) so that air was pulling from the rest of the house into the kitchen and out the windows (the plastic will tell you which way the air is flowing). * You do not want air flowing in the reverse direction (from the kitchen into the rest of the house) because it can carry the dust into the rest of the house!
Just FYI, we ended up having to walk outside through our front door to be able to get to the rest of the house. Not fun, but sure beats all that dust getting everywhere!
Wait for the caulk to completely dry before you move onto the next phase! Ready? Sweet!
DIY Concrete Counters:
Part 3 of 6 – Preparing the Surface
Part 4 of 6 – Mixing & Pouring
