Hello, Everybody!

[gjbingham]

If you had your plans in order and supplies on-site in advance, and had nothing but free time to build, you could probably pull off the oven in 5 or 6 weeks or so, with some occasional help from friends.

Waiting days/weeks for concrete and mortar to cure before you move on probably doubles the work time involved.

[Orrin Dean]

So, taking you time can be benificial?
I guess the next question would be what steps are the most crucial?

Orrin Dean

[Ed_]

Originally Posted by dmun

Note that this technique requires high density foam insulation, not the pink stuff from HD, and superior drainage both above and below grade.

They do emphasize in that article that you should look for the denser foam. I was just looking at Dow website for specs on the blue Styrofoam brand insulation board. The compressive strength varies a bit from product to product, but the low end is 15psi, which translates to over 2000 lb/ft^2. Seems to me that if you're doing a slab right on the insulation (rather than footings with fill as shown in the diagram), this is more than strong enough. (Especially when you consider that the reinforced slab will spread the load.)

Anyone know more about this? Am I missing something obvious?

[Orrin Dean]

Is there a good post, article or resource that explains the purpose of each feature of a wood fired oven?
For example, a circular dome distributes heat better because radiation moves in concentric circles. But why the hearth and the vent in the hearth, etc...

[thebadger]

Orrin,

I think the FB manual does a pretty good job of explaining the basics of the round WFO. You might also want to search the forum for more specific discussions.

Hope this helps.

Dick

[gjbingham]

There's a sticky posted by James called "Why a wood fired oven is round" or something along that line. Try a search or look in the newbie forum. I read it about 10 times.

[james]

Orin,

There are lots of color graphics on how ovens absorb and reflect heat, cook, circulate air, bake bread, etc. in the Wood-Fired-Cooking eBook. Check that out. There are also graphics on how wood-fired ovens bake pizza in the Wood-Fired-Pizza eBook. Those would be a good place to start.

Wood-Fired Cooking e-Book (pdf) :: Instruction Manuals, CD ROMs & eBooks :: Forno Bravo Store

Wood-Fired Pizza e-Book (pdf) :: Instruction Manuals, CD ROMs & eBooks :: Forno Bravo Store

Or, you could order the CD ROM. :-)

Forno Bravo CD ROM :: Instruction Manuals, CD ROMs & eBooks :: Forno Bravo Store

James

[Orrin Dean]

Thanks! I did order the the Manual and downloaded it at home. I've been reading the forum, at work more than at home, so the information isn't always available. I've been researching insulation board and where to get it around here.
I just feel better with more information.

[dbhansen]

Originally Posted by Ed_

The compressive strength varies a bit from product to product, but the low end is 15psi, which translates to over 2000 lb/ft^2. Seems to me that if you're doing a slab right on the insulation (rather than footings with fill as shown in the diagram), this is more than strong enough. (Especially when you consider that the reinforced slab will spread the load.) Anyone know more about this? Am I missing something obvious?

Ed, I'm no expert but I think the math says you're right. I'm putting the pink "Foamular 150" under my 80x88" slab (see my web album) because according to my calculations it will be subject to less than 1 psi, much less than the 15 psi it can support. A cubic yard of concrete weighs about 4,050 lbs. The 0.83 cubic yards of concrete in my slab will weigh roughly 2200 lbs, and the insulation will cover about 4,600 square inches. Assuming all that weight will be on the insulation (which it won't in my case, since the edge of the slab will rest on a block wall), that's only 0.73 psi.

Correct me if I'm wrong, but I think an oven resting on an 80x88" piece of insulation (7,040 sq. in.) would have to weigh 53 tons to reach 15 psi (106,000 lbs / 7,040 sq in = 15 psi), right? Owens Corning recommends Foamular 250 (25 psi) for under-slab insulation, but it may be overkill for WFOs. Now someone please correct me before I pour my slab!