40” Pompeii in Rhode Island

[NewEnglandNewb]

I was able to get the first layer of under floor insulation down last weekend. I had enough left over tile from previous projects laying around to use that rather than buying mosaic squares like I have seen used in many recent builds. I placed them glazed face down. Then I covered the tiles with screen to keep the P/V-crete out of the channels between the tiles. Then I knocked out a form that is 3” tall and filled it with P/V-crete. I used a ratio of 2 parts vermiculite, 3 parts perlite, and 1 part Portland cement.

I was traveling for work for the first half of this week so it sat for 4 days before I was able to see how it setup. It was really solid when I took a look today! Next step is putting down 2” of calcium silicate board and I can start playing with bricks.

[NewEnglandNewb]

The plan is a squirrel tail. I still need to figure out exactly how I’m going to do that. I do want some insulation over the dome under the flue so it retains heat better. My current thought is to use some P/V Crete to level the path from the vent at the front of the oven to the top of the dome, then put a sheet of calcium silicate board down with a clay flue liner laid on top that. I’m definitely open to ideas on how to do that.

[UtahBeehiver]

A squirrel/beaver tail venting will be required to have the vent go out the center of the outer structure. Ovens that have a vent out the top of the dome do not perform well.

[NewEnglandNewb]

I pulled the forms off the hearth pour after 9 days. I drilled the weep holes through from the bottom and layout out the floor on the hearth. Next step is to add tile. I did pick up some bug screen to add on top of the tile so the P/V Crete doesn’t clog the channels for the water to drain through.

[NewEnglandNewb]

While I haven’t seen any builds that look like what I’m planning on this site, I can’t say the idea is original. I spent a bunch of time scouring the web looking at pictures of WFOs to see what I like. I do really like the look of an exposed dome, but I will stick with my original plan to build an enclosure. My goal is to make it look something like these two ovens while incorporating all of the great ideas from others on this site.

[RandyJ]

I will be excited to see how this turns out. It is always fun to try a new and different design. I would definitely recommend not doing a igloo unless you are planning a substantial roof over head. Otherwise you are doomed to have water problems. I have seen a few have their vent come apart from freeze thaw cycles. Just my 2 cents.

Randy

[NewEnglandNewb]

The plan for the p/v Crete is half vermiculite half perlite all mixed with a ratio of 5:1 with Portland cement. I think it was a post from david s that I saw which recommended combining the two.

I finished up a small extension of the patio to connect the WFO. Pretty happy with how that came out. I’m going to try and clean up around that area now to see if I can get some grass to grow before the whole area turns to weeds this summer.

[david s]

Yes, good idea. You should be able to easily drill up from the bottom about an inch into the vermicrete, then glue some insect screen over the holes from the bottom to prevent wasps blocking the holes up.

[UtahBeehiver]

Coming along nicely, 5 to 1 p/vcrete under the CaSi gives you enough strength. See attached.

[NewEnglandNewb]

Thanks david s. Yes, there are holes cast into the hearth under the floor insulation as well as outside of the floor/dome OD where the ceramic fiber insulation will be in case that gets wet to give the water an exit path. My plan is weed mat over the tile to keep the vermicrete out of the channels for the water exit path. I was thinking about extending pins up into maybe the first 1” or so of the vermicrete to give the water a better exit path out of the insulation. Bad idea? Overkill?

[david s]

I see you’ve planned for creating weep holes in the poured slab, good move.
Also if your plans are to cast a vermicrete slab over tiles, you’ll need to hold it up with some weed mat or insect screen so it won’t block the channels between the tiles.

[NewEnglandNewb]

I got the hearth poured yesterday. I formed out arches over the front and back entrances to the wood storage and poured those monolithically with the hearth. 25 bags of concrete later and we got it done.

There was a 20% chance of rain when I woke up so I figured I would go for it. It started down pouring right when we finished mixing. We pulled out a tent and carried on.

My 15 year old daughter loves finishing concrete. She got the job of vibrating with a sawsall with no blade (including from underneath) and then got to work with a float.

It is now covered with plastic and a tarp to let it cure for at least a week. Up next is underfloor insulation, then time to start playing with bricks. My underfloor insulation plan is porcelain tile, 2” of perlite/vermiculite concrete, then 2” of calcium silicate board.

[rsandler]

There's another recent build that did their base half-round (This one)--I guess it's the new trend! Looks neat, though I can only imagine the challenges in building the forms etc.

As others have noted, there's no great answers on insulation. It's expensive and hard to obtain. Another vendor similar to Distribution International is SPI which seems to have locations in New Haven and Worcester; not sure if either of those are better than DI in Sharon. One thing to inquire with the vendors is whether they have the insulation in stock or whether they'd do a freight charge to bring it in stock. DI in California needed a freight charge if I wanted it promptly, but was willing to waive it if I could wait for them to fill up a truck with other orders. But, conditional on paying the (exhorbitant) freight charge, they delivered to my house (more than an hour from their warehouse) for free. You'll have to figure out your own trade-offs of time vs. money vs. bother.

[david s]

IMO low duty fire bricks are fine for the dome, but medium duty is a better choice for the floor. High duty bricks are really hard to cut and will cost you lots in diamond blades.

[mongota]

https://community.fornobravo.com/for...es-medium-dutyI don't think I've seen anyone use a round base. Good to see a new style of design!

Brick availability is a constant issue, it's been discussed in many previous build threads. I'm sure a moderator will pop in, but I know in the past the recommendation has been if you can get medium, get them. If you can only get low duty, no worries, go with that. Top of my head, but I thought low was in the 1700F-2000F range, and medium up around 2700F. Flatbread cooking is done in the 900F range, while I seldom shoot temperatures anymore, I don't ever recall seeing anything over ~1150F. I can't see a wood-fired pizza oven seeing high enough temps and enough thermal cycles at high temps to cause a break down in a low duty brick. I know I've seen quite a few builds that used low duty bricks and I never saw a complaint afterwards.

If your look will be similar to the "stone dome" I have on my oven, my oven has been exposed to CT winters for quite a few years. Zero issues. The stucco render on my dome was coated with Thoroseal, it's vapor permeable. My stone veneer went over that. Any coating you put on your dome, I highly recommend it be vapor permeable. You always want to offer a path for super-heated vapor to escape. That might come off as a bit dramatic, but it's just good building practice.

Insulation? Good luck! Like I messaged earlier, I travelled a bit to find affordable and proper insulation. Hardest part of my build, as well as the most expensive, was the insulation, but I went with 4" of blanket over and 4" or board under.

Your ourdoor kitchen looks terrific. The oven will complement it well. Looking forward to your progress!

Firebrick link may be attached to my post. Not sure if it will work...

Best, Mongo

https://community.fornobravo.com/for...es-medium-duty

EDIT for spelling.