Creating Concrete Countertops

One of the last big project for this studio is the counter tops. I decide I wanted to go with concrete. And I was told I could make them myself. Since I never attempted it before, I consulted my buddy Shane to guide me through the process of creating them.

There a few reasons I decided to go with concrete--

1) Cost. Since my budget for this project has gone out the roof, cost is very important. The actual material costs are quite low, I only spent around $200 total for all the counter tops in my studio. But, if you had someone do the concrete counter tops you would pay the same price as you would for granite. Making the forms along with mixing and pouring the concrete is very labor intensive which is the reason why having someone make them costs so much.

2) Appearance. Concrete has an industrial look that you can't get with other types of counter tops. Plus you can do anything you want with it--add designs, I put some small glass tiles in the ones I made, but you can do whatever you want.

Materials list (This is not a comprehensive list--but will get you started):

-Melamine

-Crack resistant concrete (I used 80lbs bags)

-re bar or wire mess or both

-sheet of galvanized steel (for hole openings)

-BLACK silicone

-screws & drill

-level

-concrete trowel & edge trowel

Here's the steps I took to make the counter tops:

1. Make a template for the forms.

I laid out some pieces of cardboard on the top of the cabinets to make a template that I would base the form from. 

2. Creating the forms.

I created these counter tops top down--so the bottom of the form is the top of the counter top. I used 3/4 in melamine to make all the forms. I used melamine because it's has a smooth surface which will in turn make the top of the counter top smooth. I bought a couple 4'x8' sheets from HomeDepot. (Warning: These babies are heavy. You might want to get someone to help you move this stuff.) I placed the template on the sheet of melamine and traced it. I then used a circular saw to cutout the bottom of the form to the exact width and length I wanted my counter tops to be. I decided I wanted the counter tops to be 2" thick so I made the sides of the forms 2 3/4" and screwed the sides to the outside of the bottom piece which left me a 2" depth for the inside of the form. Make sure to pre-drill the holes for the screws.

this is the form I created for the bathroom

3. Cutout sink hole.

On the forms where I needed to have round holes for the sinks(like the one above) I cut the size of hole I wanted out from the bottom piece of the form with a jigsaw. I then used a piece of galvanized steel(from the HVAC section in Home Depot) cut to 2 3/4" and wrapped it around the hole opening and secured it with screws. It might be a good idea to double up a couple pieces to reinforce the wall in some cases.

Here's an image of the galvanized steel screwed into the inside of the opening to create the sides of the sink hole opening.

4. Caulk all the edges.

I used Black 100% silicone sealant around all the edges and seams. This will give the top of the counter top a nice rounded edge. Although you can use any color of silicone you want, I used black because you can see it easily. Concrete will show everything. So it's very important to remove any excess, or anything for that matter, that you don't want to see because concrete will show it.

5. Add Extras.

I decide to put in these tiles for a more decorative/creative look to the counter tops. I put a dab of silicone on the front of the tile to make it stay in place.

 

I then placed them in form face down(since the top of the counter top is the bottom of the form) I made sure to squish it down flat with the surface so the tile would be flush with the top of top edge.

Here's the tiles placed in the bathroom form in the pattern I decide to do. The concrete will surround the tiles and when you pull out the finished concrete from the form they'll stay in the concrete.

Here's tiles in one of my other forms...

I decided in the form for the desks I needed some holes for computer cables and such, so I used some conduit pipe to make a half circle and placed it into the form.

6. Level the form.

I made sure the form was level before I poured. I placed a level across the top of the form to check and put shims under the bottom of the form where necessary.

7. Pour the concrete.

I mixed and poured enough concrete into the form so it was 1/2 full. I then used an electric sander around the outside of the form to vibrate out all the air bubbles. I paid specific attention to the corners to make sure the concrete filled them. After I got all the air bubbles out I place the rebar and mesh into the wet concrete and fill the remainder of the form up with mud. I screeted the top and then vibrated the edges once more. I only vibrated the concrete briefly when it was full because the rebar and mesh will actually rise to the top if you vibrate it too much. I know it doesn't make sense but it will. I then smooth out the top with a trowel for an even surface.

The freshly poured desk countertop.

And here's the finished bathroom countertop. 

I used a razorblade to scrape off the excess silicone that was left on the front of the tiles.