Concrete countertops…one third the price, twice the effort, one of a kind!
We bought this house in East Austin a few years ago and it needed a LOT of work. The first year we spent most of our time and resources adding a master bathroom, replacing the roof, a ton of siding, and all-in-all getting the house to a functional/livable level.
We recently protested our taxes with the City of Austin and won! We then refinanced the home through Iron Harbor Mortgage, got a great rate, and locked in the new taxable value under our homesteaded!
In the process of the re-fi we realized that we could get a home equity loan at an amazing rate! With a little extra cash, we started chipping away at the updates we want, starting with the kitchen.
We priced granite out around $2500, and then I got the brilliant idea to make concrete tops for around $500. Even though it was a lot of work this would leave us some extra cash to move a wall and remodel a bathroom….I forgot how much work these thing are, but it is worth it!
Here is a visual journey of the process.....
First you make the mold. Measure twice, measure again, cut once. The form is ¾ Melamine. Cut to 25” wide. I then ripped 2 ¼” side rails for the forms to make the finished depth 1 ½”s. I would have made them thicker, but at 1 ½ inches the finished product is about 18 lbs. a square foot, and that was heavy enough for me.
NOTE*** This is the countertop that had the under-mount sink in it. This was the last one I did. I used this as the example because this was by far the hardest one to make!
The form
Next I laid out the template for the under mount sink.
From the remaining melamine I traced the template and cut out the sink form. Since the Melamine was ¾”, and the counters are 1 ½”, cutting two templates and stacking them gave me the perfect 1 ½” height I needed.
Once I cut out the under-mount form I laid it out using a framing square to ensure everything was square and where it should be. Note: I probably could have moved it back from the front edge another ½”.
Using an extra piece of wood, I clamped the sink cut out form down, then screwed it in place from the bottom.
Since the Melamine is just open particle board on the sides I used packing tape to keep the wet concrete from absorbing through the sides.
When I laid the template out on the form I marked the faucet location. Using a hole saw I drilled a 1 ½” hole and inserted a piece of 1 1/2” PVC in to the form its self. I used packing tape on the bottom to keep the PVC from falling out the bottom and used silicone around the top to help keep everything plumb.
Then the real work begins. Mix’n that concrete! I used the Quikrete Countertop mix from Lowes. The instructions say 1 gallon of water per bag, but I found that to be VERY dry and hard to work with. I went with about 1.5 gallons for this one and it gave me a much smoother final product.
I bought a mortar bucket for $12 and mixed it with a shovel. I have always heard the dryer you can get away with the better. With a very dry mix I had a lot of worm holes. Worm holes are blemished in the surface caused by air bubbles. We will cover that later.
***NOTE: In hindsight I would have used closer to 1 3/4 to 2 gallons of water and bought a concrete vibrator to get all of the bubbles and worm holes out! even though this ended up giving me a super cool finish.****
Then I filled the mold ½ way with the cement.
Then I added a 3/16” welded wire with 3/8” rebar surrounding the sink. I threw on some Stucco wire mesh on top of that for good measure, and tied them all together with bailing wire.
****NOTE: keep the metal 1 1/2 to 2" away from the edge of the form****
Close up!
Then You just fill the form up with more cement and run a 2x4 across the top to get it level. I had to do this a few times. I would remove all of the high spots then fill the low spots and repeat until I was happy enough. Remember the bottom is facing up so it doesn’t have to be 100% perfect, but the closer the better.
NOTE:**** if you wait 10 to 30 minutes the water will rise to the top ( I am told the pros call this cream or the leche). once this happens it is much easier to smooth the back using a magnesium trowel.****
I waited for 72 hours before I popped the form out of the mold. First I removed the side walls. Next I pulled the screws out of the bottom then cut the sink mold in half with a sawzall. I popped the under-mount insert out in 4 pieces.