Measuring your Hearth

[james]

Re: Measuring your Hearth

Welcome aboard,

Definitely. That's what I did. Rather then doing 1" of FB Blanket and 4" of Vermiculite, I used 3" of FB Blanket. It's thinner, better insulated and easier to install.

James

[DanaMac]

Re: Measuring your Hearth

Hi,

New to all this but building the oven this week. Can I double the insulationg blanket and cut back on the thickness of the vermiculite shell?

[jahysea]

Re: Measuring your Hearth

Hi,

I have a 42" oven and I've never wished it was smaller. Lots of times I've wished it was bigger.

I know insulation is very important, but if it where me I'd sacrifice some insulation around the bottom of the oven to gain the space inside.

If you take the wider dome approach, might be best to get advice from one of the engineers on the very best insulation material for the space you have. I suspect it's a ceramic blanket, but not sure. The blanket could be coated with portland/stucco just like anything else.

This type of use is pretty common for my oven:
http://www.fornobravo.com/forum/phot...index.php?n=91

[Balty Knowles]

Wall Insulation

My oven design is for a 39" dome leaving 4" for insulation all around to a ciircular brick encasement, 2 bricks thick. I would like to increase the floor size to 42" leaving only 2-1/2" for insulation. I was thinking of using some of the soft white insulating firebricks around the bottom of the dome as insulation between the oven wall & outer brick wall. As the dome curves away from the wall allowing more space I can replace the insulating brick with loose vermiculite.

The white bricks are expensive but I think a bigger oven would be better.

Any thoughts on this.

Balty

[james]

We get a lot of questions on hearth size for the various oven sizes, and as there is not an "exact" hearth size for each oven, I am posting the method for how you can calculate the hearth size that works for your site.

I am also attaching a drawing that you can use as a worksheet to calculate your hearth size.

STAND WIDTH

For oven width, take the exterior width of your oven (oven floor, plus oven wall width), then add 10" for your insulation (1" insulfrax and 4" vermiculite), then add the thickness of your enclosure walls (1/2" for an Igloo, 2" for a metal stud wall, 4" for a concrete block split, etc.)

For example, a Casa90 (35.4" cooking floor) is 40.1" wide externally. That means the stand for an Igloo enclosure should be 51" wide. 40+10 (insulation)+1 (enclosure walls).

If you are building a 42" Pompeii oven, you have 42 (floor)+9 (walls)+10 (insulation)+1 (enclosure wall) = 62".

STAND DEPTH

For the oven depth, you take the depth of the oven and vent, then add 5" for rear insulation, then wall thickness, and then space for your oven landing.

The Casa90 is 43.5" deep, including the vent. If you want a 12" landing, the hearth should be 43.6 (oven and vent)+5 (rear insulation)+.5 (one wall) +12 (landing) = 61".

The 42" Pompeii oven works as follows. 42 (floor)+9 (walls)+6 (vent floor)+5 (rear insulation)+.5 (one wall)+12 (landing)=74.5".

You can find the dimensions of the Forno Bravo Casa, Premio and Artigiano ovens in the installation guides here:

http://fornobravo.com/pizza_oven_ins...tall_home.html

James