We are still working on our RMH build
. We were thinking a pebble-style would be the way to go but changed our mind and are going with cob. We are working off of Erica & Ernie’s “Bonny Convection Bench” 8” plans.
This plan is good for a suspended floor and has the convection aspect which will help heat more of our home.
The original plans use a firebrick firebox with 2” of perlite & fireclay beneath and around the sides of the firebox. We are using the Walker SuperHot J Eight Inch ceramic fiberboard firebox.
My question is: How much perlite/fireclay is needed beneath and on the sides of a ceramic fiberboard firebox, if any?