Has anyone made concrete table tops/counters?

[LFS19]

I’m currently making a TV cabinet which I plan to finish with a concrete top. Loads of people seem to get great results with the stuff, and it’s very versatile so far as colours and stains.

From what I gather the process is also relatively simple: If you’re building a 2 inch top, you’d build a frame out of melamine, poor in an inch, then add some support and poor the other inch. Skim the top off and vibrate to rid the air bubbles. Once it’s set you can finish it how you want.

The question is how to support it and fundamentally what mix to use. Regarding the support I was thinking rebar, but I don’t know what size.

For the mix, there are a lot of American recommendations online, non of which are sold in the U.K. Quikrete actually do a countertop mix in the U.S. but there doesn’t seem to be any here.

Has anyone done this? Any advice would be much appreciated. Many thanks!

 

[MARK.B.]

Probably better to use some form of mesh rather than rebar , plain old cement will do the job and you can get additives to colour it or you can get white cement, make sure your frame is well put together ( you can rub a bit of diesel on with a rag to help with sticking) don't be tempted to remove the frame before its dry and don't try to dry it to quickly or it is likely to crack.

 

[Inspector]

Taunton Press published a couple books on them back when people read to get information. If I remember correctly the author gave the ratios for mixing your own concrete from the basic ingredients. Looks like he wrote a third.

https://www.amazon.ca/Concrete-Coun...ountertop+taunton+press&qid=1618427010&sr=8-1
https://www.amazon.ca/Concrete-Coun...ountertop+taunton+press&qid=1618427010&sr=8-3
https://www.amazon.ca/Concrete-Home...ountertop+taunton+press&qid=1618427010&sr=8-7
Pete

 

[LJM]

Are you making it in a mould or forming it in situ?

 

[Ttrees]

I helped me da make one when I was a teen.
Used rebar, he must've bent them using the house fire.
Used concrete pipes for the legs with the rebar inside and large mesh for
the 4" slab.
Got large beams and made a platform on the gas cylinders for underneath the shuttering.
Could have done with some more cylinders as it dipped to one side a bit.
Used it about twic or three times, as those pesky crows kept messing the place up.
A big electricity pole was moved since.
Be nice to have a few steaks on it, if the restrictions ever end.

Tom

 

[mossycave]

I made one a year or so ago as an experiment for a coffee table. Melamine mould, used a pre-mix (but I don’t remember which sorry), and used welded 1”grid as the support. I used crushed glass in the base of the mould to get that sparkly effect on the top of the slab. Use plenty of screws on the mould to keep the sides square, caulk the joints to prevent leaks, and spend way longer than you think you should vibrating it to get bubbles out. I used a combination of hand tapping with a hammer, hammer action drill, oscillating multi tool, all with a dull edge on the sides on the mould. Leave it for at least a week before you de-mould. Wet polishing with diamond pads on a pneumatic sander took an absolute age and makes a real mess, so consider where you do that. End result for me was a good top surface, but the edges were a bit messy, and a bubble remained in one edge, which never looked right after filling and ultimately not good enough for indoors. The slab is now sitting in the garage somewhere waiting for me to do something else with it. We still don’t have a coffee table . Good luck.

 

[SkinnyB]

I made a concrete bar last year, used a melamine form and some old metal mesh fencing to lay into the concrete for reinforcement. I also added black concrete/cement dye in powder form to colour it.

Let it sit for four days in the form, three days out then polished it up. The book I have says to do it while the concrete is still 'green' bit soft and still curing which makes it easier to polish. It then recommend coming back after two - four weeks and giving it a final grind with the high grit polishing wheels.

I used some cheap polishing wheels from amazon with a cheap variable speed polisher and used a hose to add the water while polishing. To finish I applied multiple coats of concrete waterproofer and let it really sink in. over a few days. I finally used some clear paste wax to seal it. Been outside for a year and still looks really good. For vibrating I used an old bench grinder with some offset weight on the spindle and screwed it underneath. Worked a treat.

I can't remember the ratio but possibly used maybe 1 bag cement to 3 sand. I think you want a highish cement ratio. I made a planter a couple of weeks ago and the mix was to sandy.

I would try a small form and make some samples up.

https://www.skinnerdesigns.co.uk/product-page/polished-concrete-bar

Get this book, very informative and helpful.

Concrete Countertops: Design, Forms, and Finishes for the New Kitchen and Bath: Cheng, Fu-Tung, Olsen, Eric: 8601200621594: Books - Amazon.ca
Concrete Countertops: Design, Forms, and Finishes for the New Kitchen and Bath: Cheng, Fu-Tung, Olsen, Eric: 8601200621594: Books - Amazon.ca
www.amazon.ca

 

[OldWood]

I wouldn't.

My daughter who is clearly in a grey phase of her colour life, had a professionally one cast for her kitchen. The guy knew what he was doing and did a good job but the finish is a PVA skin to prevent stains (think drinks!!) entering the concrete and I am not convinced that will last particularly round the sink in her case.

Because of the weight all the gable ends of the worktop sections had to be doubled up. The process took a onsiderable time; preparation, casting, waiting for it to dry - and had to be kept cool - polishing and then a finish.

 

[Sideways]

The original Harry Ramsdens chippy restaurant has / had tables made with polished marble chip tops.
After a few years of having vinegar spilled on them daily, they were dull and eroded.
Polished / diamond ground concrete makes a decent factory floor. They even make boats out of concrete but i'm not convinced.

 

[TRITON]

I've heard you can use fiberglass matting in place of rebar or mesh. broken up and layered in.

I found a book on concrete in a local charity shop and gave it to my sister, who had discovered concrete wasnt as scary as she first thought. Theres a section if I remember about adding coloured dyes to said runny stone.
I'll have to get a loan of it back, see what it's got to say.