Concrete offers a lot of advantages when it comes to a surface used in kitchens. It’s extremely hard, it’s cheap, and done properly it can look almost as good as granite or marble while being more durable.
It’s also a lot cheaper, and most people should be able to easily make the addition to their home without too much difficulty.
Follow along and we’ll show you how to add a fantastic new addition to your cooking space with a few simple steps.
Victoria, Homethods Author
Table of Contents
1.) Calculate How Much Concrete You’ll Need
You’re going to need to gather together some stuff before you get going, but compared to the cost of a slab of stone you’re looking at pretty minimal costs.
We’re going to cast them in place, so using something like Quikrete is pretty much essential or you won’t be able to use your new counters for days or weeks as the concrete cures.
As a general rule of thumb, you’ll be able to get about 4 square feet per 80lb bag of Quikrete mix at a 2 inch depth.
This means you’ll need to measure the area you’re planning on filling in beforehand, it’s pretty simple though. Multiply the length and width of the slab, in order to get the square footage you’ll be needing, then buy as much as you need. Remember to convert all units to inches before you begin, then you’ll need to divide by 12.
So, if you’re going to build a 3’x4’ island, you’ll convert the units to inches.
1728”/12=144” or 12ft²
12ft²/4=3 80lb Bags of Quikrete
Simple enough, right?
You’ll also need to subtract for any appliances that might be in the area such as sinks or stove tops.
You’ll need the following in addition to your concrete:
A Screw Gun
Melamine Coated Particle Board
Two Level Sawhorses
Putty Knives of Various Sizes
Table Saw or Circular Saw
Get it all together in the garage or front yard, you’ll be needing most of it pretty quickly in order to get going.
2.) Building the Frame
Building the frame is really the hardest part of the project, and if you haven’t worked with concrete before you’ll find it’s a bit more complex than you’d think. That said, most people should be able to pull it off quite easily.
The melamine needs to be cut in order to make a “cast.” Any cut outs you make will also need to be included in this part of the process. Take your time, but just chop the boards to size assemble them with the screw gun.
Cut the exterior strips to the desired depth and screw them on tightly to the bottom board.
Drill the melamine first, particle board is prone to cracking and you’ll want to use at least 2 ½” screws in order to make sure that it holds together. These will crack the boards if you don’t drill a pilot hole.
For insets, which won’t be reinforced with extra wood, it’s a good idea to make sure that you drive a screw every 3-4” along the boards.
Concrete weighs a lot, so you’ll also need to reinforce the outside of the frame with 2x4s. Screw them together and you’ll have your frame.
After all of this is done, you’ll want to add caulking to the corners. If you’re not used to using silicone, then lay down painter’s tape first and then lay it over. Use a wet finger to smooth it out and remember that this is going to effect the final look of your countertop.
If you mess up, rip off the tape and try again.
Coat all of the melamine lightly with olive oil once you’ve got the frame completed and are ready to pour, it’ll make separating things much easier down the road.
Done right, you’ll have your mold and be ready to move on. Poke it a bit and make sure it’s sturdy, but as long as you were careful your mold should be functional.
3.) Pour the Concrete
At this point, you’re ready to pour the concrete and fill the mold in.
Mix the concrete, following the instructions that come with it and pour the mold about halfway. Add in any pigments that you’ve decided upon.
A note on pigments, if you’re planning on using them try making a small 1’x2’ tray a few days before you’re planning on doing the countertop in order to make sure it’s really the color you want.
After the mold is halfway filled, lay down the steel mesh as a reinforcement after clipping it to size.
Fill the mold the rest of the way in, and you’re almost done. Now you’ll want to use a piece of 1×4 or other fairly large object in order to smooth out the concrete’s surface as much as possible. Once that’s done, let it sit for a few hours.
Come back and finish the smoothing job with a trowel, then it’s time to let the whole thing sit for a couple of days after laying a plastic sheet over the whole counter to let it cure properly.
4.) Remove the Framing
Removing the framing is a simple matter. Grab a large flathead screwdriver or a small pry bar and break it apart. As long as you don’t try anything too crazy, you’re not going to hurt the concrete at the end of the day so just break it off of there.
Once you’ve gotten it off, call a couple friends and lift your new countertop onto its final resting place.
5.) Finishing the Counter
The first thing you’ll want to do is check for imperfections in the countertop. Small bubbles and cracks have undoubtedly emerged, and it’s up to you to decide if you’re going to leave them or try and fix them. Concrete patching compounds work fine for this.
If things are too rough, you’ll need diamond based sandpaper to smooth it out. Use an electric sander if you can, concrete is tough.
After this, you’ll need to decide how to finish it. We recommend a brush on gloss polyurethane coating which will add both shininess and durability to the concrete.
And voila, you’re done.
It’s a lot of manual labor, and you’ll need to be a bit careful but you can save quite a bit of money by doing this whole thing yourself. Give it a shot, it’s sure to awe your friends and you’ll have a kitchen centerpiece you can be damn proud of.