is 2" enough thermal mass?

[mpjfitz]

Hello

The fire bricks I have are quite an unusual shape. The measure 8" x 9" x 2". I'm ready for a lot of cutting to make the dome

I'm ready to lay my hearth soon. But I'm concerned that 2" won't be enough thermal mass?

I can easily add some more 'mass' if need be?

Any advise will be appreciated

Thanks ... Mick

[fxpose]

Re: is 2" enough thermal mass?

I assume you're talking about the floor?
As far as the dome walls you can cut your bricks into quarters which will give you at least 4" in thickness.

[mpjfitz]

Re: is 2" enough thermal mass?

Yes I'm talking about the floor.

I've already started cutting them into 4 for the walls

Mick

[kebwi]

Re: is 2" enough thermal mass?

Hmmm, that is 80% as thick as "normal" firebricks at 2.5". I'm unsure of the implications. If you can find a supply for "splits" you can lay down a half-thick layer first. Alternatively, depending on how much cutting you want to do (I did a lot, had no problem with it), you could dice your 8x9s into thirds and lay them down edge on. One axis would yield slightly under 3" (blade width costs you about 1/8" loss), the other axis would yield slightly under 2.67", which would be almost exactly 2.5", the standard thickness.

[texassourdough]

Re: is 2" enough thermal mass?

I would prefer a thicker hearth based on my experience. Unfortunately my experience is not with bricks so.... I fear that you will lose a lot of hearth heat to the pie and need to pull coals out periodically to recharge the hearth. Not a big deal necessarily and everyone (in my experience needs to do so occasionally (at least to get rid of a blob of cheese or sauce) but less often is better. I would encourage more mass.

Good luck!
Jay

[mpjfitz]

Re: is 2" enough thermal mass?

I am considering adding maybe and inch of refractory (damp mix) mortar and bedding them on that. I know it will make them hard to replace at a later date ... but I'll let my Gran-kids work that one out

[DrakeRemoray]

Re: is 2" enough thermal mass?

I think that the floor of the commercial ovens that forno bravo sells are thinner than 2"...So it could probably work. For retained heat cooking, I think the dome holds most of the heat. I think you would just have a fast heating floor...

[texassourdough]

Re: is 2" enough thermal mass?

Hi Drake!

The casa ovens have a floor that I recall as being about 1 1/2 inches but it is really heavy/dense and I think has higher heat capacity than brick so I think it holds more heat than bricks but I could easily be wrong. In my case I have my insulation below the slab so I have LOTS of mass to heat load.

Jay