Vermiculite versus perlite

[rbigante]

Any advantages to using one material over the other for the insulating hearth? Is there a specific grade that I need to obtain? I see that these are used in the gardening industry, is it the same stuff?

Thanks, Rino

[dmun]

Re: Vermiculite versus perlite

There's a silicone coated vermiculite that you don't want (it doesn't adhere to the concrete) Anything sold for agricultural use is fine. Perlite and Vermiculite both work the same. It mostly depends on cost/availability.

[rbigante]

Re: Vermiculite versus perlite

dmun, thanks for reply. helps alot because i'm having a tough time finding a place nearby that sells vermiculite. i may have to order online???

[adman2u]

Re: Vermiculite versus perlite

I found my vericulite in the garden shop of Home Depot is was about $16 for a huge bag. I mixed it about 50/50. I also placed a single piece of cardboard between my insullation and solid pour for expansion. So far so good after about 20 fires but ask me in a year. Pictures in gallery under name showing steps for my pizza oven / tandoori grill / smoker combo. Have done all 3 successfully in same unit.