42" Pompeii in Eastern NC

[Caliea]

**EDIT: For those looking for info on a barrel vault - I changed my mind and am building a 42" Pompeii** 9-12-16

Hello all.

I've been lurking on this site for a few years now, slowly gathering information while dreaming of starting my own oven. Well, I'm finally at that point! I'm planning on documenting my build here, so I'll go ahead and flood you with info

Here's my basic info:
- I have zero masonry experience, unless you count tiling bathrooms and showers. No brick, mortar, or cement experience to speak of.
- I have a fairly decent grasp of basic construction techniques, and have access to a vast array of tools and equipment through my father and husband. (yay for tool-hoarders!) Both my husband and father are engineers, so the structural stability/design/code issues aren't an issue as much as real-world experience and guidance.
- I own a bread/pastry bakery, so my main interest is baking breads and other long-term roasts,etc. but I also have 4 sons who are quickly approaching their teen years, so I can only imagine that lots of pizza making will be in our future. I'm hoping to put enough mass in the floor to enable bread baking, but still have the ability to cook pizzas and flatbreads with a live fire going.
- i have read (and read and read) the "Bread Builders" plan by Alan Scott, and have also downloaded and studied the Pompeii plans from this site. I've also read a ton of posts on these forums to try to absorb as much knowledge as possible before asking questions.


I am currently planning on building a barrel vault style oven. I decided on the barrel style mainly because the Pompeii style looks fairly intimidating when I contemplate all those rectangles turning into a hemi-sphere. The shaping on the barrel vault seems a bit more within my abilities.

Along with the oven, I am planning a bit of an outdoor kitchen area. There will be a 36" long counter on each side of the oven, and then a brick BBQ grill area a bit further down the line. Right now, the plan is to build the foundation of the oven and cabinets with CMU blocks, and then frame up the surround of the oven and the base of the cabinets with metal studs and clad them in some fashion (possibly a stone or brick veneer). The countertops (and possibly the entrance into the oven) will be poured concrete.

To further complicate my plans, this will all be situated against the end of a raised wooden deck with pergola. The approximate elevation of the deck surface is 24", so all my foundations will be an additional 24" from the ground that would be found in a 'typical' install.


As I'm laying out my design, I'm able to clarify some of the areas I don't quite understand yet. To that end, I"m hoping for some clarifications.

(1) Hearth construction - as I try to assemble knowledge from so many sources, this is what I've come up with for the hearth construction: (from the top down) (a) two layers of firebricks in a herringbone pattern, turned 'flat side' up (b) 2" FB board for insulation (c) 3.5" (non-insulating) concrete slab for structural support. My question is: is this enough thermal mass to allow for bread baking or overnight roasting? i"m planning on wrapping the dome with an insulating blanket over the concrete cladding.

(2) Ash slot - my plan is to fire the oven, use it for pizzas if needed, then remove the coals and use them in the BBQ area for other cooking. This would allow me to put in bread to bake while grilling. I think maybe an ash slot would make removing the coals more complicated?


I've attached a very basic sketch of what type of setup I'm thinking. This is from the 'deck' side of the oven, and doesn't show the additional height build up that will be required to reach the existing deck height.

Thanks in advance for any input you have for my hearth construction and the ash slot!

[UtahBeehiver]

Caliea,

Nothing wrong with a barrel but domes are not that difficult to build using the right techniques. Look at this thread where the original builder was going to build a barrel but the forum talked him into a dome. He us currently under construction and you could ask him about it. Domes offer cooking advantages dues to the shape. FB offers an inexpensive baseline plan for $3 with walks you through the build process.

https://community.fornobravo.com/for...9952-new-build

Couple comments. I am not sure why you need two floor layers of fire brick for thermal mass unless you really plan on doing full scale bread baking. I would consider a little more insulation under the floor, 2" will suffice but another 1" would be beneficial for multiday cooking. Trade the cost of eliminating the 2nd floor layer for additional floor insulation.

[thevance53@gmail.com]

Yep, that's me. I am just bringing my 7th chain over the entry arch. It is a little intimidating when you start and I had a huge issue understanding how the dome ties into the entry arch, but the bottom line is you just cope the bricks into the arch where they hit. That actually is the fun part. Cutting of the bricks is a piece of cake. Just follow JR's Dome calculator and slightly adjust from there. The hardest parts were figuring out how to build a good, workable IT, and the cutting table. On setting the bricks, it is key to set a couple of starter bricks and let them set up for some time before tapping bricks around them. I had to reset starter bricks multiple times until I figured that out. It does take a long time to set one brick at a time and keep the level of the courses. What scared me about the barrel vault was possibly the need for additional support around the barrell or buttressing. Either way, it is a lot of work and takes quite a bit of time, but I am glad I made the decision to switch. Good luck.

[UtahBeehiver]

Just a side note. Deejayoh is the developer of the brick angle spreadsheet. But JR is the CAD master on the forum.

[deejayoh]

If you want a double-thickness hearth for bread baking, you can also lay the bricks on edge (runners) instead of stacking them - that will give you 4.5" of hearth instead of 5"

But you will get enough thermal mass for bread baking from a single layer of bricks. The 4.5" thickness is most useful if you want to have enough retained heat in the hearth to bake several batches of bread off the same firing. Even with 2.5" of hearth, I have seen posters here who bake baguettes, then boules, then something else. 4.5" really approaches commercial needs.

oh, and with all that mass, you want more than 2" insulation. I would go with at least 4" if your goal is bread baking

[thevance53@gmail.com]

Ooops, sorry for the messing up the credits, although they both deserve kudos for all of the time and effort they have spent on this site along with all of you other contributors.

[Caliea]

Thank you all for the comments! I have to say, I originally intended on building the Pompeii style, but cutting each brick to fit is intimidating. I've been lurking around more of the 'should I or shouldn't I" forums, and now I'm leaning towards the dome style. I figure, if I'm learning anyway, I might as well go all-out. Your encouragement makes me think that I'll at least be able to have a functional oven, even if maybe it's not perfectly cut.

So, I think I'll do the dome style, probably the 'higher' dome calcs on the FB plans. I'm leaning towards the 42", mainly because we tend to have big dinners when the families gather, and I don't want to be stuck cooking pizzas just a few at the time. Also, this is our forever home, so will probably be the only oven I ever build. Don't want to regret making it too small.


Thanks for the hearth advice. I'll go the one layer of fire brick on the hearth surface, and use 4" of insulation between the hearth bricks and the underlying structural slab.

Mike, I've been lurking on your thread - thanks for asking all those hard questions, so I didn't have to

I'm hoping to start forming up my foundation within a few weeks. My husband and I are planning on taking a wood fired oven class at King Arthur Flour at the beginning of October. I'm hoping to at least have my foundation and hearth slab poured by then. That way, when we actually use an oven for the first time, I'll have a chance to ask all those detailed questions regarding quirks of use that might make a difference in my final oven design.

Thanks again for the advice, and I'll keep posting in this thread once I make some progress/ have more questions.

[UtahBeehiver]

Forgot to give you a link to some of the more documented pompeli builds, there are others but these are linked in one place.

https://community.fornobravo.com/for...n-the-archives

[Caliea]

Well, I have over 200 8x8x16" CMUs delivered to my house this afternoon. If Tropical Storm Hermine doesn't flood us out, I'm planning on getting the foundation for the oven and the countertops figured out this weekend. I guess by next week I'll have figured out if I've begun an amazing project or if I've lost my mind!

[Caliea]

Well, the storm dumped 6" of rain and then moved out, so we had the chance to work today. The wet clay was much easier to remove, and we got all the areas dug out and the first course of blocks laid.

We're not doing a foundation slab. Instead we're burying 1 course of block and lining the trench with dry Quikcrete. Hopefully we'll finish dry stacking the walls tomorrow, and then we'll pour some cells full to stabilize the whole thing.

I've attached before, during and after pics of today.

[Caliea]

Day 2: we laid all the courses for the oven and the counters. 200 blocks and 2500# concrete. We're wiped out!

[Caliea]

I did learn a tip: if I expect my husband to put in two hard 9-hour days on his long weekend off, I'd better have a beer in the house at the end of the day! Oops....

[Caliea]

I need some guidance. I'm planning the hearth slab pour, but can't quite figure out the transition from entrance of the oven hearth (approx. 7" above slab: 3" firebrick and 4" insulating board) to the surrounding prep area/countertop. When I see pictures of enclosures, it looks like you can often see the slab peeking through the exterior facade. But that slab would be below the height the pizza is actually cooking, correct?

I'm hoping to pour a concrete countertop area just in front of the oven entrance and off to each side. Is this somehow raised that extra 7" from the hearth slab?

Halp! I'm confused.

[fnbroken]

Hi Caliea,

That's correct - you will need to pour a second slab on top of the hearth to raise the work surface to the desired height.

Take a look thru some of the builds here and there are a number of ways to achieve this...

A good pictorial is here of Mitches... http://blender.formworks.co.nz/oven/

As an aside - have you had any advice about putting a 1 tonne oven on a 9 course high stand with no foundation? That's a lot of weight on very little footings....

[Caliea]

Hi Fnbroken,
Thanks for the link. and the clarification. That's some gorgeous work that Mitch has done - I imagine I'll be poring over those pictures to gain insight on my own build!

I have had advice on the foundation for the oven - maybe more than I needed? My father is a Professional Engineer that has a foundation design consulting business, and my husband is also a Professional Engineer who works with soils and civil projects. They both had input on this foundation. Honestly, if it were just me, I'd probably have a slab per the original FB plans, but since it's what they do, and I have to live with them, I'm doing it their way I figure it's easier to live with the disdain from forum members than it is to live with annoyance from the engineers in my life

Thanks again for the reply!