Outdoor built in bbq

I would (and did) skip the plywood.

I mentioned the one at my buddy's place... that was a chipboard base with 2 or 3 inches floated. The chipboard had completely decomposed from moisture (and likely termites).

You'll need more support for the countertop than just a layer of ply and Wonderboard. I'd use Wonderboard as the base, but float concrete at least 2", and preferably 3" reinforced with "rabbit cage" wire.

If there's any flex (and there will be with the ply/wonderboard combo) the grout lines will crack, and you may break a tile, or they may pop loose.

 

So you're saying, put the cement board down and then add a 2"-3" concrete top on top of the cement board reinforced with chicken wire? Sounds like a lot more work haha. Well, hmm I don't think I would have chosen chipboard as a base. I would pick something a bit more solid and apply a water resistant finish.

Anyway, here is the latest shot. I added 3 coats of Redgard to the outside of the cement board. I cut about a half inch of cement board off of the bottom because it was touching a little too close to the ground. I'll need to caulk the base which I plan on doing today.

 

If you're going to lay concretete, we did a cast-in-place 1 1/2" concrete with fiberglass reinforcment in our laundry room and kitchen. I bought bullnose edging molds. They were $200 for 8 eight-foot bullnose peices and 6 eight-foot straight edges (we used those against the wall and for the cooktop knockout).

I used Quikrete Countertop mix (~$15/bag). We used 4 80 lbs bags in the laundry room and 11 bags in the kitchen. We also mixed in some Buddy Rhodes concrete dye to color it (one can for every two bags). The fiberglass is about 2.5 lbs for each bag (bottom layer only).

My wife and I did this ourselves:
This is about 14 sq ft (7'x2')


I did this with my wife and her son.
Kitchen was about 55 sq ft

 

the concrete looks really nice. I just thought of something. Not sure I can use plywood anyway. Anything combustible has to be at least 1ft away from the grill.. hmm

 

Those counters are way beyond my skill level... but I always cover my flatwork with tile or pavers

Ron, looking at your frame again, you've got more support than I first thought.
I'd say you'll be okay with two layers of Wonderboard, bonded together with thin-set.

But I would skip the ply. Even with a waterproof coating, it's not going to last forever, and you won't get a 100% seal.
It will expand and contract with humidity.

 

Two layers of cement board huh..I've been using hardi backer rather than wonder board. The only one "rated" for exterior use is durock.

It's so hard to find the "right" one to use because everyone online has different opinions and they both seem to work, granted they're properly protected.

Hardi backer is pretty pliable, I'm thinking if I do end up using just cement board, I may use durock. My frame is pretty strong, it would take quite a bit of force to move it. Even a cement counter top shouldn't phase the integrity of the frame. And really there isn't any huge gaps between the steel studs. 8 inches at the most except one spot which is about 12"

 

The gaps is what I was concerned about. You don't want ANY flex on the tile countertop. But when I saw how close your braces are, that concern minimized.

Wonderboard is basically just concrete with a glass wrap and smooth sides. Two layers bonded with thinset would be as solid as 3/4" of concrete, and with your support structure, I think would be just fine.

 

3" of concrete on that much area is going to way a shit ton , just make sure you don't have to move the thing later , lol

 

Oh yeah I'm moving it before I start adding anything else. I;m just about ready to start adding the stone veneer. I won't be doing the concrete counter top

 

Is that standard or metric?

Looking good OP!

 

http://www.youtube.com/watch?v=HNmJr7cQlkQ
It's not that bad actually. My wife and I had never worked with concrete before. We took Buddy Rhode's 3-day class in San Francisco. The class was $1200 each but it saved us money in the long run since we did the work ourselves. I used the same zCounterform molds he used in the video. I used glass fibers instead of ladder wire in the laundry room. This video is from a couple of years ago. His class doesn't teach ladder wire any more. It's all GFRC or glass fiber scrim but the methodology for the rest of it is the similar. In the kitchen I used glass fiber and ladder wire just for piece of mind.

With the glass fiber you just mix 2.5 lbs of it with each bag of concrete for the bottom layer (none in the top layer or you'll see the fiber in the cement surface). So for example, our laundry room countertop took 4 bags of concrete. We did two bags with glass fiber and filled the bottom (it's a dry mix so you pack it in by hand. It doesn't really poor). Then we mixed up two bags without fiber and put them on top, screeded, wood floated and then steel troweled the surface.

We also used Quikrete's Countertop mix instead of the Buddy Rhodes cement as it was about 1/4 the cost. It wasn't as nice to work with as Buddy's mix but it turned out good.

We did the laundry room countertop as our first run.

 

I was actually watching that video yesterday. That end results was awesome! I see you're in escondido too. Maybe you can save me the $1,200 dollar class and come help me

 

That's Imperial.

Canadian would be "Metric Shitload"

 

* metric shit tonne

 

I'd help for sure. I have the mixer, a float and trowel. I'll be out of town next week though and wont be back until saturday.

 

Ah, I was kidding, but that is very generous of you. I'm thinking I can get away with using 1/2" hardi backer. It will be overhanging the island by about 1.5". I will redgard the entire thing while I have them off.

 

looks good !

What are you using as a welding machine ?

 

It's a lincoln electric mig welder

So I got the counter tops all cut out and attached to the frame. I used the Redgard on the bottom and top side and sealed between the walls and counter with a bead of silicon. I got the gas line all hooked up as well ready to connect to the grill

I also started on the stone veneer yesterday and it is going to take quite a bit longer than I anticipated. Luckily the stone is quite easy to cut. I simply score it about 1/4" where I want it cut and then tap it with a rubber mallet and it makes a clean cut. I think it's going to look really good when it's all finished.

 

Looking good!!

 

So are you just going to use the tent for shade or whats your plans for that?