36" Pompeii Build in the desert

[jim lofaro]

Thanks all. The support on this forum would rival any 12-step program out there. I read some of the controversy around the use of ss thermal breaks and fall on the side of the ‘breakers’ for looks alone.

Our story so far:
Mortared the soldier course using the following method;

• Put down an aluminum foil layer around the perimeter of the floor
• Dry fit the soldier course on the foil
• Mixed up approximately 5 pounds batches of the FB mortar to a peanut butter consistency
• Soaked the soldiers for ~ 5 minutes
• Buttered the side of the ½ soldiers on the side that would contact the previous soldier
• Used a water spray bottle to mist the previous brick
• Pressed the brick into position.
• Tap the new brick with a rubber mallet
• Rinse and repeat so 30-odd times

If I had it to do over I would not have buttered the brick up to the oven-facing edge but started around the middle of the brick running the back edge. Would use paper and not foil to keep the bricks from adhering to the floor and diatomaceous earth for good measure. Ended up with a puny brick in the final reel after dry-stacking a number of times (see photo).

Took the first 5 soldiers down as I did not care for the texture of the first mortar mix and some separation of brick/mortar occurred. We have had a few nights of significant freezing, a least for southern Arizona (16 degrees F), and wanted to see if that would separate the bond between mortar and brick. So far so good.

Ordered the Angleizer but it looks like General Tool does not support the software anymore (https://community.fornobravo.com/for...ndows-software). Any thoughts about another source for the software?

Another question; would the internal/external arches be mortared onto the floor or free-float like the solider course?

Jlo...

[UtahBeehiver]

The floor heat break I put in was roughly 5/8" x 2.5" thin wall 316 SS tubing stuff with CaSi board. I salvaged from a ss table. There has been some recent discussion on effectiveness of thermal breaks. I chose to do it because I wanted to do it and it did not take a tremendous amount of effort, time or money. So each to their own.

[jim lofaro]

1*2 was my guess. it does look cool for sure. Thanks.

[deejayoh]

all good information. here is a question for Russell; what size is your ss rectangular tube floor thermal break? Is it worth putting one in?

not Russell... but I put in a 2" x 1" SS Tube. I got lots of advice that it was a bad idea... and I have no way of telling what the impact is as a heat break. But it looks good, and it acts as a nice break between the firebrick in my oven and the soapstone I put in the vent.

[jim lofaro]

all good information. here is a question for Russell; what size is your ss rectangular tube floor thermal break? Is it worth putting one in?

[SableSprings]

Yes Jim, don't mortar the soldier course to the cooking floor perimeter. When the oven is fired there is movement as the bricks expand (and when things cool down). You want to allow the dome and the floor to shift independently. It used to be recommended to put a layer of foil between the perlcrete/vermicrete insulation and the bricks of the dome. Again, this was to ensure some expansion slip between the two materials during heating & cooling of the bricks.

I think with the advantages of the ceramic batting over the more rigid insulation materials, this slip joint concept is pretty much "old school" and considered unnecessary. I actually used diatomaceous earth between my dome bricks and insulation to provide slippage and an "anti-critter" barrier.

[jim lofaro]

With the foul weather we are having I took the opportunity to read up a bit on the soldier course. Seems the general option is Not to mortar the soldier course to the floor (my ½ brick soldiers set directly on my cooking floor). Another suggestion I believe I read was to put aluminum foil under the soldier course to prevent the floor/soldier bond. Sound about right?

[UtahBeehiver]

I used bagged concrete mix that had pea size aggregate plus a liquid acrylic fortifier. I live in Utah where the winters are harsh so I have had some counter top damage plus I think I also over work the concrete when I embedded the glass. I you have a more shelter area or a warmer climate it should not be as much as an issue.

[jim lofaro]

Russell, just went thru the photo log of your build and damn, i must say that is the most amazing piece of art i have seen so far. well done sir and i will be contacting the Smithsonian on your behalf, A question, the concrete pour with the glass, did u use an aggregate/Portland mix or more of a stucco type mixture?

did a bit of a review of going vertical posts and see that RCLake doubled the amount of water for Heat Stop 50. let me try that if it warms up.

[UtahBeehiver]

Nice work and plenty of floor insulation.

[jim lofaro]

finished the floor. there were a few 'peel catchers' so i ground those down. just about to go vertical. any advice for mixing/using the FB mortar?

[jim lofaro]

Ahhh the best advice ever, Relax. A bit tough since i have never layer a brick in my life but let me try. Fireclay and sand it is.

Serenity now!!

[SableSprings]

Here's a link to a short thread on taking off the sharp brick edges (chamfered edge). Using the herringbone pattern, selecting your best bricks, and spending the time to set the bricks level is really about all you need to worry about. The experience for most of the forum folks is pretty much summed up by Novaslo (post #3) and Deejayoh (post #8) in this referenced thread. My bricks are set in the herringbone pattern and I have only one spot where an "edge" has developed...and I easily work around the minor problem.

https://community.fornobravo.com/for...or-brick-edges

I helped set a modular system floor that was level until we put the dome pieces in place , it only raised up two edges so that putting things in was no problem but when you pull ashes out there is a catch on the floor. No big deal and a little grinder action there would be quick and easy...but it just hasn't been worth getting in the chamber with a grinder. I really think that type of installation problem is what the Forno Bravo guide is meant to cover. The use of sand/fire clay to help set the floor is really all you need. (Use a mister to lightly dampen the media, then run a notched trowel over it...this is just like setting a tile floor in the house. The grooves created by the trowel give you the ability to tap/adjust each brick down level with the adjacent bricks. The moisture will help to firm and "set" the sand/fire clay base so things don't move around later. )

Relax...

[jim lofaro]

Thanks again Mike. Looks like the Pompeii instructions actually say 'grind' the floor and not sand:

{{{

Tips and Hints
If possible, hand select your cooking floor bricks for quality, ridges and chips, and use the best you have for the cooking floor.
If you do end up with ridges that catch your peel, you can grind them out later.

}}}

I was thinking more of sanding the floor as to get rid of the some of the rough edges were the brick meet. The link to the sanding thread:

{{{

https://community.fornobravo.com/forum/pizza-oven-design-and-installation/pompeii-oven-construction/4491-sanding

}}}

The oven will be an igloo type with a stucco finish and a DuraVent vent. Never hurts to add a bit of buttress however.

[SableSprings]

Your specs look good as does your picture layout on the setup.

1) The fireclay/sand mix does not have any significant adhesive properties

2) Not sure what you mean by "sanding the floor". I laid down a thin layer of sand/fireclay on top of my perlcrete floor insulation so I could level and set my cooking floor bricks. No sand has come up from the leveling mix to the cooking surface. Any minimal space between those bricks fills in quickly with ash. I've been using my oven pretty steadily since the fall of 2009 and have some minor scrapes & markings on the cooking surface...but nothing that makes me think about replacing bricks.

3) I have buttressed the sides of my vent/landing area because I placed a pretty hefty chimney stack over those arches. I wanted to make sure that the outward thrust of that weight on the arch was completely contained. If you are doing a simple arch with a normal collection area feeding into a standard metal chimney pipe, your layout should be fine. If you wanted to add more brick on top of the landing arch, putting in some additional bricks on the sides as buttressing would be something to consider (IMHO)

Are you going to use some sort of render over your dome insulation? Most folks that have used the ceramic batting over the dome, hold it down with chicken wire which also acts as a great base adherent for the first render coat. I worked on an installation of a modular oven and we laid down chicken wire under the ceramic board so when we put the batting over the dome, we simply cut & pulled the wire up and over & tied it in place. Lots of ways to finish insulating the dome and it's certainly a ways down the road for you...

Looking forward to watching the build come together.