[woodenSpoon]

Who has done it and what kind of concrete did you use. I'm considering this for an out door table so it won't be very large

 

[brockmiera]

I haven't but I'd like to follow this thread. I'm thinking about concrete for a basement bar I'm doing.

 

[Mort]

Just a couple sacks of Quikrete, as long as it's air-entrained, should work for you. Make sure to have some wire mesh, so it doesn't crumble. Concrete's compressive strength is awesome, but its tensile strength sucks, hence the wire mesh.

As far as the process to finish it, all I can figure is what I've seen on DIY Network shows, so I'm sure someone more knowledgeable will be along shortly.

 

[concretepumper]

I have played around with this several times. I have always used sacrete from lowes just be sure to measure the amount if water and color into each batch so you don't get different color tone. And yes the forming and pouring is is very easy. But the finishing it is a brute, sand polish sand polish polish polish polish polish very dirty job but the rewarding part when you stand back and look at the finish project

 

[woodenSpoon]

Thanks for the input guys. I am pretty confident about making the forms and all. my main concern was the type of concrete. You don't haver to have the aggregate right?

 

[brockmiera]

Thanks for the input guys. I am pretty confident about making the forms and all. my main concern was the type of concrete. You don't haver to have the aggregate right?

You dont have to as long as you understand the properties of cement. I dont know why you wouldn't use aggregate though. Here is some good reading I found.

http://www.cement.org/tech/cct_aggregates.asp

 

[Bondo]

Just a couple sacks of Quikrete, as long as it's air-entrained, should work for you. Make sure to have some wire mesh, so it doesn't crumble. Concrete's compressive strength is awesome, but its tensile strength sucks, hence the wire mesh.

As far as the process to finish it, all I can figure is what I've seen on DIY Network shows, so I'm sure someone more knowledgeable will be along shortly.

Ayuh,.... I play with concrete, but don't call myself anymore than an ambitious Diy'er...
I understand concrete's properties fairly well, 'n always use alota steel, as I Am a Steel guy...
I haven't tried any of this, but can see where I might wanta someday,...

Anyways, to get to my question,... for concrete countertops, etc,...

Do you see any value in usin' glass fiber, as well as the wire mesh,..??
Maybe less steel mesh, 'n abuncha glass fiber in the mix,..??
Or,...
Does anybody know if the glass fiber, ruins any chance of gettin' a nice finish, after ya pop it outa the mold,..??

 

[Mort]

Its possible you'd be able to see some of the fibers after you mess with it. You can't use them in exposed aggregate driveways for that reason.

 

[Canucker]

I`ll be following this thread. Definitely want to try this:yes:

 

[Tscarborough]

Fibers have changed composition from the old days, they are not glass they are plastic and do not stand up like the glass did (The alkalinity of concrete destroyed normal glass fibers).

Things to consider for concrete countertops:

Thickness: 3-4 inch is OK with bagged concrete, although I would never use the big box 3 bucks a bag fencepost crap for one. If you want to go thinner, you will have to exponentially increase the flexural strength of your mix.

Aggregate/reinforcement size: For a 3-4" slab, #3 (3/8) rebar and 3/8" aggregate are fine. Get smaller than that and you will need to reduce both aggregate size and reinforcement size. 2-3" slabs should use 1/4" or 9 guage wire and 5/16" max aggregate.

Finish: Are you grinding the finish or leaving it as-is hard troweled? If you want a slick finish without exposing aggregate, you will have to pour it face down in a melamine mold.


Normally, you will want a high loading of both fibers and latex to increase the flexural (as well as the compressive) strength.


The most important thing with concrete countertops is to understand what it is and also what it is not. If you want it to look like granite, use granite. If you want it to look like stone, use stone. If you want the random rustic look of concrete, or the polished style of terrazzo, use concrete.

Oh, and be sure to seal it when you are done.

 

[stadry]

find guys who do this work decorativeconcrete.com/forums, concretelocator.com, & concretecountertopinstitute.com,,, some use premix'd bagg'd stuff & others developed their own proprietary mixes,,, no pro i know uses any conc mtls apron/vest stores,,, we got bagg'd c-top mtls from buddy rhodes, elitecrete, & doug bannister's stamp store

did cast onsite & precast ( melamine forms ) but had more luck o'laying existing c-tops & 2" ply using bagg'd mix for 1/2" thick tops,,, stapled carbon fiber grid for reinforcement altho mix properties didn't require it - no fiber or latex,,, IF you choose fiber, propane torch makes quik work of removing the hairs

c-top smoothness depends on your tools & skill - we own'd a planetary trowel/polisher but $ 1,600 may be budget killer for you:yes: not a rentable tool far's i know here in atl