Saturday, January 03, 2009

A Little Better Explanation

OK, this is a crappy little drawing but if you click on it and enlarge it you might be able to make sense of what I did with the sink counter. I know my photos of the pouring did not show things well. I was in a hurry and didn't realize I had not taken any photos until after I already had one bucket of mud in the form.
Basically, I located all of my wall studs that were withing the boundaries of the counter and drilled a 9/16" hole in each stud about an 1 1/4" down from the top of grade. Which is to say, down from what would be the surface of the concrete. It is 2" thick concrete and I tied a mat so you have to account for stacking two layers of rebar. I then inserted #4 rebar into each hole in the studs, glueing each one very well with construction adhesive and letting them extend out into the counter about 12". This gave me two #4 bars in each wall, which gives you more strength since the dowels are on 2 sides, rather than just on one wall. The countertop being set into a corner allows for both of your outermost corners to be supported. A triangle is one of the strongest forms and if you can keep the back corner down, the front can't tip forward.
I then tied #3 rebar to the #4 bars and long enough to run the length and width of the counter. I used #3 because this would take up less space, allowing more concrete around the bars but wanted stronger ones (the #4's) in the wall for obvious reasons. You can bend #3 bars pretty easily but #4 is much harder to bend.
I had to bend two of the #4's to get them to go into the studs straight but miss the sink area where they extended into the counter area. Now, I have a rebar bender to make this easy but you can bend it using a long secure pipe (a cheater bar) or a stump and nails etc.
I think I actually tied more rebar in the counter than what the drawing shows but I can't remember exactly. You get the idea though.
The counter is 42" long and about 22" deep, so it is not really that big of a surface. However, it is still pretty heavy and I think if I had made the counter any larger I would definately put 2 brackets under it for support.
So, FC, basically, it is attached to the wall the same way your mantel is.


karl said...

nice, thanks for the detail.


Floridacracker said...

Thanks Annie!
That's exactly what I thought you did.

Aunty Belle said...

Youse clever. Know ya's so happy to have it done! Yore place is comin' along, really reflectin' yore skills.

Happy New Year!

edifice rex said...

Hey Karl! no problem; it's a pretty simple idea really.

Hey FC! Yeah, I figured you probably already knew.

Hey Aunty! thanks. Oh, I am very happy to have it done; should have got off my butt and finished it so long ago. Happy New Year to you!

Ed Abbey said...

Thank you for all the postings on this subject. Someday I'm going to build my own house and I've always wanted stone or marble countertops but lately, I've been interested in concrete counters and then behold, you write many posts on doing one yourself. Since I've done a lot of concrete work in my past, I know it should be something I can handle and now I have a clearer idea of what is involved. Excellent series of posts!

edifice rex said...

Hey Ed! Well, glad you got some good info from it. I plan on doing another on just general concrete finishing. If you have poured a good bit you should be just fine doing your own countertops. Once you see how concrete reacts and works, you know what to expect.