FB Brand Insulation Getting Started Discuss FB Brand Insulation in the Pizza Oven Design and Installation forums; Thanks so much for the replies. Mfiore, I think using a DRY mixture of sand/fireclay is the ticket...just like laying ...

[splatgirl]

Thanks so much for the replies.
Mfiore, I think using a DRY mixture of sand/fireclay is the ticket...just like laying patio pavers. Duh. I wish I had thought of/tried that before I wet down a whole bucketfull and tried to trowel it on.
Anyway, I ended up doing as I proposed above which worked pretty good. As you pointed out, James, the particle size of vermiculite is fairly large, and actually, I used perlite which was worse, but it worked great with a little dry sand/fireclay mixture dressing. Success on attempt #1 today! Cooking floor is in and my soldier course is set and ready to be mortared.

I put a tape measure on the boards I'm using before I started the do over just to make sure I wasn't being overly fussy. There was 1/2"+ variation in thickness from one piece to another measured at the exposed edges, plus I'd say I had another +1/4" high spot on one board and close to -1/4 low on another.

Again, I appreciate the comments and advice.

cheers
s.g.

[blacknoir]

James, would you recommend a sand/fireclay mix or a refractory mortar layer between the FB board and the firebrick? If sand/fireclay, what ratio would you recommend?

I just ordered my boards today from FB btw.. can't wait to get started laying brick!

-Shay

[james]

I think dry and mortarless is fine when you are setting discrete bricks. Try 50/50. That should be good!
James

[Glosta]

James- I am building a 42 inch Pompei oven, at your recomended Tuscan height. How many square feet of dome insulation will I need to get 3" of coverage. Also with respect to the with solid insulation, I assume the oven floor insulation extends all the way under the fire brick wall? Since your 42" Pompei kit includes three(3) pieces of solid insulation, is it safe to assue this is enough? Also do you stock or can you recommend and source for oven doors? Last-why doesn't anybody use an ash dump in the base or back wall? Thank you for your advice. Glosta

[dmun]

Last-why doesn't anybody use an ash dump in the base or back wall?

It's not needed. A primarily pizza oven generates only a shovel or two of lightweight wood ash for each firing, which is easy to shovel out the next day. In a bread oven where you were raking out a lot of hot coals and live fire, an ash dump to a masonry enclosure might be useful, but it would necessarily be located right in your busiest work area that you're always using. You would never want to put it in the back, or anywhere else in the oven chamber, as that would cause airflow, turbulence, and other problems.

Finally, having an ash dump in the front, without elaborate angle chute, ends up right in the middle of your wood storage area.

[ErFornaio]

Quick question on the insulation. Is there any reason why we wouldn't want to cover it with construction paper prior to laying down the outside stucco layer? I am asking because my so called Waterproof stucco wasn't exactly waterproof last year and in my rebuild am trying to keep the oven a bit more dry.

[100million]

try looking at my build and us Alum foil and it will be WATERPROOF

[dmun]

Is there any reason why we wouldn't want to cover it with construction paper prior to laying down the outside stucco layer?

Heat some up and smell it: that should answer your question. The larger question is whether you want an absolute vapor barrier between your oven insulation and your outer layer: it may prevent water getting in, but if your oven gets wet from another source (Igloo oven owners report that the place between the dome and the flat surface is a problem) it will also slow the re-drying of the insulation.

[100million]

I feel placing it after the insulation is a good thing as a vapor barrier and I would fire the oven atleast a dozen time before sealing it up just to help dry it out then you can see how bad the cracks arer and if anything needs fixed before moving on to the insulation process

[Royal Ranger f16]

Okay, I am getting kind of overwhelmed with the Hearth insulation news. I was going to pour the vermiculite concrete mix over my pad this weekend. Should I wait and get the new FB board or do a combination. Cost seams like it adds quite a bit.