This instructable shows how to build a simple concrete countertop. There are several sites on the net with good instruction and lots of details, including one here on Instructables. This project is much more basic for those who may be interested in trying to build one but want to start with something simple (relatively speaking). The countertop was for my friend's new kitchen island and was built by just the two of us with no prior experience. There are no bells and whistles, just a plain rectangular top 74 inches x 37 inches, 2 inches thick.

This will also be a reference as to problems that could arise, mistakes that could happen (read, mistakes we made), and fixes/work-arounds in case they happen to you. You don't want to spend the time building something like this only to have it end up as a small patio in your backyard instead of the countertop you wanted. Believe it or not, the concrete is much more forgiving than you'd think.

On to the good stuff...

Step 1: Gather Your Materials, Have a Plan

The basics for making a concrete countertop are simply building your mold, pouring and finishing the concrete. There are several acceptable materials for building the form, but we chose cheap and easily obtainable...melamine coated particle board. You'll need a piece larger than your desired finished dimensions, we chose a 4 foot x 8 foot piece 3/4 inch thick. Other items needed are:

- Additional melamine boards for the sides of the form
- Sturdy and LEVEL sawhorses to build on (our finished top weighed around 400 lbs)
- 3/8 inch rebar for inner support
- Remesh for more inner support
- Wire for attaching the rebar and remesh to the form
- Screws for building the form (we used 3 inch and 1 5/8 inch drywall screws)
- Drill (you MUST pre-drill the particle board to avoid splitting)
- Saw(s), circular hand saw and/or table saw to cut the form sides. We also used a chop saw.
- Silicone caulk in a color easily seen on your Melamine (we used black)
- Concrete tools consisting of float(s) and trowel(s)
- Long screed board
- Hacksaw/bolt cutter/wire cutters for cutting your rebar, remesh, and hanging wire
- Level
- Rubbing alcohol
- Concrete (of course). We used Quikrete 5000 without additives like fibers or water reducer.
- Pigment of choice. We used a little black so the natural color would just darken a bit.
- Concrete mixer. Ours was rented and we mixed and filled everything in 4 hours.

Before you build your countertop, you should definitely build a test form. We built two 1 x 2 foot forms with rebar and remesh to test pouring consistency, color, technique etc. This also allows you to test finishing techniques on something other than the real countertop. Please don't skip this step.

Plan the size and shape of your top and mark it out on the Melamine sheet. We didn't need to make any templates since ours was a simple rectangle and was going on an island and not against a wall. Be sure to take into account the thickness of the boards being used for the walls when drawing the guidelines.

*While our sawhorses were both sturdy and level, they were only on the ends of the mold base. After curing, we noticed a very slight bow in the countertop. In retrospect, we should have had two additional supports across the length. *
Nice job! I haven't done a counter yet but I've worked with concrete (professionally) quite a bit and I'd just like to note two things -<br><br>Wear gloves! The nitrile rubber ones work well, but anything is better than nothing. Concrete will jack your skin up.<br><br>You also mentioned something about pulling the form sides off to allow the concrete to dry more fully. Concrete actually cures as a chemical reaction with water, not like paint which dries by evaporation, so that's actually not necessary. Unless you're going to try to finish the edges, leave the forms on. You will actually notice the concrete pull away from the form slightly when it's well cured (wait at least a week for a project like this) and the forms should come off really easily. You could also paint or prime the particle board edges if you wanted to reuse them.
<p> I think your project turned out great but just to help people out who are trying to do this for a large project or an entire kitchen. PLEASE PLEASE do not try without the proper additives and fiberglass for your back coat if your not doing cast in place. Its much harder without the proper admixtures and the fiberglass will help to keep your counter tops from cracking. You can use regular concrete with water reducers but its only a few hundred dollars more on a large kitchen to do it with proper materials and if your going to put out the effort don&quot;t skimp on materials.</p>
<p>What additives and fiberglass do you recommend? amounts/ bag?</p>
<p>I'm not sure if that's an insult or not. If it is, keep in mind that one persons instruction doesn't guarantee another's skill. Personally, I'm impressed. It's CEMENT! As an island top! Ingenious and beautiful! Can't wait to try it. </p>
<p>I'm building an outdoor kitchen area and it will include concrete counter tops. There are 4 sections to the counter. I will need 4 separate counter tops. Can you reuse the melamine board - or is it only good for using 1 time?</p>
<p>The melamine is susceptible to water damage and swelling from the wetness of the concrete. However the white portion of the board isn't...so the edges will need to be replaced because they get concrete on them and can swell/break down. All that being said though the melamine is relatively cheap ($30) so if I were you I would just another board to be safe. </p>
<p>i cant get quickrete 5000 what can i use in a basic concrete mix of 1 part water 2 part cement 3 part sand</p><p>are super plasticizers absolutely necessary? </p>
<p>Rough price on material and about how much time did it take from start to finish? Also can you give a rough idea on the weight? I'm looking to build a desk with a concrete counter top but I want to make sure the frame can hold it</p>
<p>Firs of all - great work guys!</p><p>Second, a question. I am not understanding one of main points. You keep writing 'concrete'. Concrete is mixture of ingredients. I am trying to understand how to produce suitable concrete. Of course, cement is one ingredient water is another. But what are ratios? <strong>And should I add anything else</strong>, (sand)? </p><p>Thanks a lot guys!</p>
<p>Could possibly just get a cheap sander and screw it directly to the form, perhaps have the form resting on something that would allow for a little movement but ofc still keep straight and level, could go crazy and mount it to a washing machine on spin :)</p>
<p>I have a wonderful concrete counter top that friends and I made. I sealed it and faux finished it in various shades of green with hand painted embellishments. I embedded several cast iron pieces next to the range. I just love it. I rented out my house for a short while and my renter must have climbed on the counter top, and now I have a large crack in the corner of my island. Can you give me any advice on how I can repair this? </p>
Counter top installers use epoxy to join slab cuts.
<p>I guess it is better to use non steel reinforcements. Something like composite ones. They are stronger and cheaper. Also they say no to corrosion</p>
<p>We have been building concrete countertops for our clients for several years now and have developed some techniques hope they help.Most voids can be filled with a similar(or for contrast a different) color grout as can be wiped over surface and with fine sand paper comes off nicely and adds texture to the counter top also not sure if it was mentioned but to achieve the smooth finish the mold is to be poured upside down and use a tool such as random orbit palm sander or 1/4 sheet sander pressed to edge of form for vibration, a short while but not too long a time , will help to consolidate aggregates and reduce air pockets, as far as form release ....the melamine will not have a problem with separation nothing is required . sealing is a whole topic on its own...hope this helps some</p>
<p>Another thing to try is using glass for the bottom- saves on finishing. You can even use different types of trim for sides if you can find enough, giving it a nice profile.</p>
<p>To aid in removing your form try a little diesel on the form before you pour. Concrete will not stick to the area with diesel</p><p>.</p>
Not a good idea, as its a countertop. Basic cooking oil with do
Great tip, but it's my understanding that the cooking oil will not dissipate like the diesel will, the cooking oil may hinder with the curing of the concrete. Concrete gets stronger over time. Additionally, the counter top will be sealed before use. Just a thought.
<p>I actually think my mix was to dry because I ended up with a lot of air pockets. I heard that you want it to clump up in your hand. I guess it has to be more fluid like.</p>
Try tapping the the side with a hammer or get a vibrator to get rid of the pin holes
<p>I saw on Youtube that if you put some form of heavy tape over the your form edge boards, it will keep concrete from falling into the scew holes while floating or screeding. </p><p>Also, I would avoid diesel if you plan on making this food safe. Try a light coat of olive oil instead, and you should avoid the concrete from sticking. </p>
<p>Thanks for the instructions. I had one problem though. I used Sakrete 5000 which I thought was a comparison to Quickrete 5000. It waid it was made for countertops but when I mixed it up I found that it had to high stone to cement/sand mixture ratio. When screeding I had to move really slowly so that I did not pull up the stones. It was a PITA! Is there a difference between Sakrete 5000 and Quickrete 5000 as far as stone to concrete/sand ratio? </p><p>Another issue that I had was that I pressed really hard to make sure that I got the concrete into the corners but apparently I didn't do a good enough job. I ended up having a lot of voids where the concrete did not get past the stones or some how the stones created a void. Either way I'm not that pleased with the results. How do I make a &quot;slurry&quot; so that I can fill the voids?</p><p>This was my first concrete countertop at my house. I'm a carpenter that's been in business for 10 years but this is the first time that I made a concrete countertop.</p>
<p>Great project! Very inspiring! </p><p>Did you use any release compound like WD40?</p>
<p>Love what you've done. I'm working on a bench top too and am hoping you can advise me...</p><p>What concrete ratio's did you use?</p><p>I don't really want my finish to be showing aggregate stone etc and more of a plain dark concrete finish...similar to what you have finished with from what I can see.</p><p>Thanks for your help!</p>
<p>Hello, very nice complementary instructable to go along with the few other really good ones. But what happened to the link to the slurry <a href="http://www.concreteexchange.com/shop_cat.jsp?catsecid=4" rel="nofollow">Fu-Tung Cheng's slurry mix</a>.?? It is a 404, thanks for the instructable I am doing my kitchen counter tops in a similar way.</p>
<p>Nice job with the instructions, photo's and insets (nice touch), I am confident I could do this after your instruction. </p>
I built a wet bar in the den and will be making concrete countertops. I am pouring in place tho... <br>
I was wondering if you or anyone else interested in doing this have thought about doing &quot;exposed&quot; concrete countertops.
We used to use a sponge dipped in slurry to wipe over the concrete. Then when it starts to dry, wipe off the excess. Also we only used 10mm galvanised mesh and it worked for much heavier applications. The only thing is that we added a chemical to stop the reaction between the cement and metal, I can't remember what the chemical was though...
Nice job!
This WILL be happening here at home this summer. THANKS!
Great, i had to try this myself and its actually dead simple, <br> <br>followed the steps, poored the concrete, sanded it down to grit 400 dry, added slurry yerterday evening, this evening sanding down dry to 400 and probably wet to 800, than top it with tung oil, mine fits on a BBG table. <br> <br>my round DANCOOK BBG was the actual mould shape to make the round hole, <br> <br>now the top of my BBG is flush with the top of the concrete tabletop. <br> <br>
If you wet your finger in soapy water you can smooth out the seams without getting any caulk on your fingers.
Most concrete counters are angle grinded to get a really shiny surface, but you seem to have achieved a reasonably good surface without it. I am doing a desk, so angle grinding is the most expensive part (I don't have a workshop full of tools). <br><br>How does the surface of your counter compare to a polished granite one in terms of smoothness and sheen?<br><br>You could be saving me a lot of work.
Hy...what kind of wax did you use?
did you have any problems with cracking doing the 10in overhang?
No, the rebar went to the edge all the way around and supported it just fine.
You mention digging the concrete out of the screw heads. If you put a piece of painters tape over each screw head, it usually stays put. Just pay attention when you are screeding it.
What was the brand of polyurethane you used?&nbsp; Can you find it at a local hardware store or did you have to special order it?
&nbsp;This was my friend's countertop. &nbsp;I wasn't directly involved in the finishing, but I believe he bought the polyurethane at Home Depot. &nbsp;Just make sure it's marked as &quot;food safe&quot; or something similar. I'll try to find out for sure the next time I see him.
Did you do any sanding?
In step 10 we went over the top with a wire brush, kind of like a very course sanding.&nbsp; Once small holes were exposed by this, we slurry filled and sanded them down once dry.&nbsp; It was my friend's counter so he did all the sanding.&nbsp; I'm not sure how course, but I know it ended up with a fine sanding and buffing.<br />

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