Insulated Pad question

[Wlodek]

I take it 2in of FB is not enough then? Has anyone combined FB with vermiculite-concrete?

W.

[dmun]

Two inches of cal-sil insulation is enough. You can use more if you want, but for home use, that's a good insulation layer.

[Wlodek]

Many thanks ... last minute wobbles and insecurities here ...

The support base is ready here ... all in local stone, came out solid like a bomb shelter but with a certain charm, will post some photos soon.

Best wishes,
W.

[tdibratt]

I am not sure I like the vermicrete on the entire pad so I was thinking of pouring say 3-4" of concrete and then pouring the vermicrete mixture in the centre of the pad where the oven hearth would be and filling in around it with concrete again. That way when I build the facade and enclosure I have real concrete to adhere to. Anyone see any potential issues with this approach? I might even add the insulation board over the vermicrete for extra insulation.

Thx

[DrakeRemoray]

TDIBratt, this should work. It is in the plans as the "island hearth" method. I would make sure that the insulating layer extends beyond the walls of the oven 4 inches, but beyond that it does not add anything and does cause some problems with attaching a facade.