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Concrete Countertops


I'm a very experienced DIY'er, and have no fear of trying something new. It's just an opportunity to grow. I want to do DIY concrete countertops. I would prefer to do a pour in place, with an undermount sink. your advice is greatly anticipated and appreciated.



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Posted 2011-11-01T14:53:59+0000  by Metropoleon Metropoleon


Hi hello and welcome to the How-to-Community.


So you’re interested in concrete countertops and not just that you’re interested in pouring them in place with an undermount sink opening ... and you did say you have no fear of trying :smileywink:


And having said you’re an experienced DIY-er I’m assuming you’ve done your research already and you have some ideas on How-To' s and what materials to use?


C TOP.jpg

My opinion on this Metro is next;


It is possible but the price is too high.:smileyindifferent:




 Well first thing you would have to worry about are your cabinets.


If your cabinets are particle board construction you should know that they are going to be under some serious stress during construction. You need to vibrate your C-Tops and you cabinets are not going to like that.

Second  to worry  about when it comes to cabinets, it’s the actual melamine framing you have to do for the “pour in place”, like you probably already know you need to drop (recess) your melamine base in to the cabinet openings for the C-Tops to sit directly on top of the cabinets.

In order to do that you need to install blocking on the underside of the melamine base and that is not an easy thing to do when you’re dealing with the particle board.


Weight, if you’re sink base is more than 33” wide that’s another one you should worry about.

You should plan for the removable supports to be installed where the sink opening it’s going to be. Keep in mind and in your I Phone :smileyhappy: you are not going to be able to install your undermount sink if there is still melamine stuck on the bottom of it.

Overhang framing, this is another challenge to successfully frame for the C-Top overhang you need to clamp the nailer board to the face of the cabinet rails and that’s one more step towards damaging you cabinets.


Now when it’s all framed out and C-tops are poured you have to start thinking about the mess that comes from the concrete finishing.You may want to consider  a hand trowel finish instead of polishing.

C TOP2.jpg

With the C-top that are poured in place continuous wet sanding it’s not an option being that  your cabinets would be soaked in water.


So this said you have to start thinking about the dry sanding. This extremely messy and even with the vacuum grinder there is just too much dust going on. Also no reasonably priced dry sanding pad can come even close to wet sanding so again you’re scarifying on the finish this time.

But the result it’s unmatched  :smileywink: and if you’re set on trying this one out I would recommend practicing screeding and troweling .You would want to know how to perfectly screed and trowel C-tops to achieve flattest possible surface  and avoid any extra grinding work.


Hope this helps.




Posted 2011-11-01T19:36:17+0000  by George_HD_CHI

Well George,

what about making forms and building CT in the garage and then setting them?


Posted 2011-11-02T18:34:20+0000  by Metropoleon

Hello again Metro and sorry I didn’t get back to you right away, I was on the short vacation.


You asked;

What about making forms and building CT in the garage and then setting them?


This is definitely something I would recommend to somebody how's looking to replicate the finish of the granite C-tops and has an ability of piecing out slabs without sacrificing on the esthetics of the kitchen.


In other words depending on your kitchen layout joining two slabs may be out of the question and you may be better off with "pour in place" or some kind of different material.

If I remember correctly once cured concrete C-tops weigh about 20 pounds a square foot and an average 10 foot slab can weight something like 400 pounds: smileysurprised:


Unless all of your friends are olympic weight lifters I would not recommend pouring anything longer than 10’:smileyindifferent:


There are some prep steps you can take to make "pour in place" a little bit easier on your work area and cabinets.


For example;

Cut you melamine precisely, there should be no gaps bigger that 1/8" of an inch.

Use 100% clear silicone caulking to seal all of the gaps in between melamine framing and cabinets to prevent concrete and water from leaking out of the form. :smileywink:

Use drill operated vibrator instead of pounding on the framing with the hammer risking on opening the sealed forms.

Concrete Vibrator.jpg

Remove appliances and cover cabinets entirely with clear plastic.

Protect all of the electrical junctions and bring power from another source.

Use ZipWall type of system to create dust containment booth and protect non working areas.


This is my favorite one Metro I have a full 4-piece ZipWall kit and I use it with almost all of my “dusty” projects.


Hope this helps and good luck with your project and let us know how it went.




Posted 2011-11-14T15:56:33+0000  by George_HD_CHI

on in place concrete countertops go on line they have lots of options one of my favorites is CHENG Concrete using foam forms.

Posted 2012-02-21T02:09:54+0000  by fabulous

You sound just like me - an experienced DIY'er whose unafraid to try something new.  I have to say, I disagree with the prior recommendation by SteelToes that you NOT attempt the pour-in-place countertop yourself.  While I haven't done mine yet, I'll definitely be doing it this summer in my dual-sinked, corner vanity master bath.  I did the shower last summer and it's beautiful, if I do say so myself.  I have also done a concrete overlay with acid-staining on the floors in my home's main living areas, and it's beautiful, too (again, if I do say so myself), so I feel confident that I'll be able to pull-off a pour-in-place countertop.  Check out the following video:   Of all the ones available on-line, I've found this the most helpful.
BTW, by using the Z Counterforms as seen in the video, you eliminate the problems SteelToes discusses.  I plan on making a couple of sample forms to practice on... and will end-up with a couple of nice stepping stones for my yard in the process.  
SO - I say, "GO FOR IT! and Good luck to us both!"


Posted 2012-12-30T17:54:04+0000  by DIY_Queen
I have the same problem as Metro only different.  I have a "temporary" laminate top in my kitchen with a built-in backsplash and I wish to remove it so I can put the "permanent" backsplash on that I want when granite counter-tops are installed at a later date.  So 3 obvious problems would be 1. how do I cut it in place, 2. how do I fill the approximate 1 1/4" opening after it is removed, and last but not least 3. how do I trim it out "short-term" until granite fills that opening.  I would appreciate any and all suggestions as I know how to remove it entirely and replace it permanently with another top.  Just trying to save a buck or 2 in the short run.
Posted 2019-04-15T14:34:49+0000  by VictorB
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