sand under firebricks?

[david s]

Re: sand under firebricks?

There has been plenty of discussion on using broken glass as an insulator if you do a thread search. It was used extensively prior to modern insulating materials. The air spaces created between the bits of broken glass are what gives you the insulation value. Curved glass is better than flat pieces because they create more air spaces.

[Dagored154]

Re: sand under firebricks?

I am using 3 1/2" soapstone bricks under the fire brick instead of the FB Board. can I just use sand underneath them and not mix it with fire clay? any thoughts.

[mrchipster]

Re: sand under firebricks?

Do you mean soapstone or insulating fire brick? Soapstone is a great conductor of heat and not an insulator, FB Board is an insulator and your plan to use soapstone will be a serious mistake. You may not even be able to get your oven up to temp due to the thermal loss.

Insulating firebrick may be a useful choice but I think it would be quite expensive when compared to FB or some other ceramic insulating board.

Just my two cents.

Chip

[Dagored154]

Re: sand under firebricks?

an old acquaintance of mine has built dozen of home and commercial ovens. and has used them as well. He suggested the soapstone bricks underneath instead of the FB board. He sure seemed to know what he was talking about. I hear what you are saying so I will speak to him when he returns from Canada.

[mrchipster]

Re: sand under firebricks?

You will go through lots of wood with no insulation under the floor.

Just because your friend builds them this way does not mean it is best practice, please research heat loss through the floor or insulation techniques on this site. I have 2.5 inches of vermicrete and 2 inches of FB board under my floor and can cook all week on one firing of the oven, pizza first night and ribs on day 6. With bread, roasts and casseroles in between.

Chip

[Dagored154]

Re: sand under firebricks?

Thank you so much Chip. I am going to order the FB board tomorrow morning and go with that design. not sure what to do with the soapstone I bought. maybe I will put it on the front face of the oven.....