Insulating slab with Super Isol

[james]

Thermally, one layer does it. 4" of vermiculite concrete has proven to be enough to effectively block heat movement, and the 2" Super Isol should do a better job than that. I think we're in a safe zone.

For the rebar, your lengths should reach to the top of block stand, but not go to the end. You want concrete "around" the rebar, with the rebar "resting" in the center of the slab, on the blocks.

From our concrete experts, structurally -- why is that true?

James

[mrpbjnance]

I just purchased it...I only bought enough for 1 layer.


Should the rebar be lon enogh to reach the blocks end to end? Or does that matter?

Thx
Mike

[Alan]

Are you using one layer or two if the Super Isol?

[dmun]

thickness of support slab

4" of reinforced concrete is what is called for: This gives you two inches on either side of the grid of re-bar. Remember to keep the ends of the re-bar away from the edge of the slab, but long enough to be above the source of support.

[mrpbjnance]

I have purchased the Super Isol board from James... (Thanks James! Your help is appreciated!)
My question is what thickness should I make my insulating hearth now so it is strong enough to support my oven. 2"...4" Do I still need to do 6"?

Thanks
Mike