Advice on Laying (circular?) insulating hearth

[david s]

Re: Advice on Laying (circular?) insulating hearth

Allow at least two weeks sun and wind on the vermicrete slab to eliminate water before building over it. Cover the thing if it looks like rain.

[Dan W]

Re: Advice on Laying (circular?) insulating hearth

So I did that. And here's the result so far. I reckon it's gunna work quite nicely.

Rest of my build is in the Aus regional forum.

[Dan W]

Hi Everyone,

I'm a newbie and just starting to build a 42'' tuscan pompeii. I've built a stand and laid 100mm (3.5inches) suspended concrete slab for the base of the hearth - now dry. There's no easily available insulating board in my region that I'm aware of (Canberra, Australia), so I'm laying a castable vermiculite/cement insulating base to sit the oven floor and dome on. The FB Plans say to lay the insulating base ontop of the concrete hearth in a rectangular fashion right to the edge of the concrete slab. My question for all you knowledgable folks out there is this:

Can you see any issues with simply laying a circular layer of vermiculite/cement insulation ontop my concrete slab hearth, just a fraction larger than the floor of the oven? I'd then lay the floor and dome ontop of that, and aim to bring the dome insulation and stucco down flush with the edge of the circular hearth insulation. I figure this would save a little bit of vermiculite, and result in a nice neat finish.

Any other tips at this stage gladly received! I'll post some pics as I go.

Cheers

Dan