Confidence help request Vault style oven build

[Bloodtoothbrown]

Hi Community.

I am literally about the commit to building a vault type oven. I have done lots of research but I wanted to do a last minute sense check. Can anyone guide me to the best plans? I am looking at a 81cmx98cm base. Its the height and pitch of the vault I am nervous of, and the heat gain to cook good pizza. And steer to what plans are best would be appreciated. Thanks in advance. Kieran

[SableSprings]

Welcome to the forum! Sorry to say that if your goal is pizza, a vault style WFO is not as good as the classic Pompeii (dome) form. Vaults can certainly work very well but tend to be more oriented to larger scale bread baking. That said (and of course, it's just an opinion), any well insulated cooking chamber/floor that you can get up to pizza temps is better than an electrc/gas "normal" home kitchen oven for this "flat bread delicacy". Do spend time on the forum looking at why the vault form needs extra buttress support and why most of us build the dome form. Good luck & glad to see you want to have a solid plan and clear purpose for your choice of WFO style.

[david s]

To add to Mike's excellent answer, it would be helpful to understand why you want to build a vaulted dome. There are reasons why in some respects it is a better form, much of it relates to what you intend to cook in it. Loading the oven with bread enables the baker to fit more loaves in a vaulted oven than a hemispherical one, because of its rectangular floor area and its vertical walls. The same can apply for roasting, particularly for high sided rectangular roasting pans. These considerations regarding pizza cooking however, do not apply.

Many, particularly first time, builders are attracted to the half barrel design because it appears easier to build than a dome. Unfortunately the reverse is true because of the inherent instability of the vault. A standard semicircular arch is quite a strong structure as the Ancient Romans discovered and used widely for thousands of years. However if that unsupported arch is subjected to enough force it will fail. The damaged section at the back of the Colosseum is a good visual example of this where each adjacent arch supports the one beside it. Where this has been removed a chain reaction of collapse occurs.
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAD

Because an oven is subjected to thermal cycling with the accompanying thermal expansion, the structure is constantly under stress. The flatter the arch (larger radius) the greater the sideways thrust. Kiln design requires either buttressing or bracing of the sidewalls to counter these forces. The temperature and therefore the thermal expansion of an oven is around half that of a kiln, but the same principles apply. In addition the expanding arch has a tendency to push out the end walls, particularly if the bricks are not tied at the corners and the end walls built outside the vault rather than under it. By contrast the dome is a self supporting structure not requiring either bracing or buttressing. There are a number of half barrel oven builds on this site that presumably you have read and some of them address these structural issues while others do not.

[Pizzarotic]

I am looking at a 81cmx98cm base. Its the height and pitch of the vault I am nervous of, and the heat gain to cook good pizza.

Kieran, I haven't see a lot of detailed plans available, it may be that the barrel vault design is so simple that they are generally not required for smaller ovens.

Your vault is just a semi circle with the radius of half the oven width. Some people will raise the arch 1 or 2 courses of bricks to gain more height for bread baking but this is not necessary or desirable for a pizza oven.

Some books that may assist are,
Building a Wood-Fired Oven for Bread and Pizza, Tom Jaine
The Forgotten Art of Building and Using a Brick Bake Oven, Richard Bacon
Your Brick Oven. Building it and baking in it
Russell Jeavons
The Bread Builders: Hearth Loaves and Masonry Ovens, Alan Scott

[david s]

There are plenty on this site. Google “barrel oven Forno Bravo”