Hearth design

[130mountainside]

I see that most builders use the '2 part' system to build identical hearth slabs- one reiforced concreate, the next on top the insulated slab made with pearlite. Question- not everyone makes identical slabs- some only insulate a portion of the top slab- is there any advantage to this 'extra' step?

Thanks

[Ken524]

Re: Hearth design

Hi Moutainside,

As long as you have 4" of vermiculite/portland (or 2" of insulation board) under the oven floor and oven walls, you are ready to go.

You can skin that cat any way you like

[DimTex]

Re: Hearth design

Mountainside,

I too wondered about that. I did not want to go to the trouble of extra form building so I laid a full layer of the insulating layer save for the cantilevered shelf I put in front, that I did make with a double layer of reinforced concrete.

[papavino]

Re: Hearth design

The reason most of us go to the effort of only insulating a portion of the top slab is that the vermiculite/cement insulation is kind of brittle, so we pour regular concrete around the insulating portion to protect the insulation from chipping off. And we can attach steel studs, etc. to it.