[mieno]

Hi
Just about to start the vermicrete insulation layer and wondering if anyone has ever used pumice stone instead of vermiculite? I have enough pumice to do the hearth but was wondering about its insulative properties compared to vermiculite - same or worse? The particle size vary between 10 - 30 mm and it is hard compared to vermiculite so I guess the slab would not be spongey like vermicrete.

Also, out of interest has anyone had any experience with clay / earth ovens? How well do they work compared to firebrick?

Thanks.