Really need some help getting started

[Matt916]

Re: Really need some help getting started

I really like the pictures of what you guys have done!! I'm attaching a few pictures of the progress I've made thanks to all the help I received thus far. I really didn't realize I would be able to do this much so fast.

Now onto building the hearth. I looked at the online instructions on how to do it and I downloaded the PDF file, but am still a little nervous about it. Mostly i'm worried that the 2X4 reinforced plywood won't hold all the weight of the concrete...i'm probably just being paranoid haha.

Also, just to make sure I understand correctly, the hearth slab is comprised of 3 1/2 inches of normal concrete on the bottom and 4 inches of vermiculite-concrete (5 parts vermiculite to 1 part portland cement)? I just wanted to make sure my numbers are correct! And finally (sorry for all the questions) why is it that in the on-line instructions the vermiculite-concrete mix wasn't poured under the oven landing area? would it be ok to go ahead and pour the whole thing vermiculite-concrete, or should some other material be used to fill in the gap. Dusty (or anyone else), do you have any advice before I move on?

like i said, sorry for all the questions, its just now that i have the foundation and stand built, it feels like this thing is getting serious and i don't want to use the wrong measurements/materials/etc.

[Matt916]

Re: Really need some help getting started

sorry...had to put these in a separate post for some reason

[dusty]

Re: Really need some help getting started

Matt,

Looks great so far. Looks huge for some reason.

Your numbers look correct and it is perfectly acceptable to pour the vermiculite/cement stuff over the entire hearth. Simpler too. I did. I built my dome right on top of that stuff.

dusty

[ttriche]

Re: Really need some help getting started

Mostly i'm worried that the 2X4 reinforced plywood won't hold all the weight of the concrete...i'm probably just being paranoid haha.

Yeah, you are. Use 2x6's or 2x8's since you'll be pouring it plenty deep. With a suitably long ratchet tie-down strap or two (and some blocks of scrap) you can crank those forms down tighter than a drum. Be sure and pound on the sides of the form a lot during and immediately after pouring and screeding the structural slab. Concrete behaves like a liquid while it is being vibrated and the resulting slab will be much, much stronger if you take advantage of this trait.

If you have any tapcons, a neat solution to the problem of how to build a 'tray' for the 3/4" plywood underlayment part is to screw some 2x4s directly onto the blocks of the stand, and then put legs at the corners and a 4x4 or 6x6 in the middle. Worked like a charm.