A few questions

[JohnR]

I posted some initial pictures of my wfo build here: http://www.fornobravo.com/forum/f43/...ild-21210.html

I have some questions:

1) I am building a barrel/vault and need some advice on cladding. I do not want to add more thermal mass than necessary yet I want the oven to be structurally sound. So... How can I insulate the walls of the oven and then support it with cladding in a way that is structurally sound?

My plan was to wrap the oven in 3" of ceramic blanket, but I think the efficiency of the blanket would be compromised if I compressed it with cladding.

2) When transitioning from the ceiling arch to the door arch does it need to be gradual or can it step down (sorry can't think of a better way to describe what I'm asking)?

3) My entry arch will not be touching the oven door or hearth. There will be a thermal break and I plan on placing the flue on the entry arches. I do not have any more Calsil. Can the entry arch sit directly on the concrete hearth or does it need to have insulation underneath?

Thanks in advance for the help... I plan on finishing the vault this week and move on to the entry arch and insulation/cladding.

John

[david s]

Re: A few questions

I posted some initial pictures of my wfo build here: http://www.fornobravo.com/forum/f43/...ild-21210.html

I have some questions:

1) I am building a barrel/vault and need some advice on cladding. I do not want to add more thermal mass than necessary yet I want the oven to be structurally sound. So... How can I insulate the walls of the oven and then support it with cladding in a way that is structurally sound?

My plan was to wrap the oven in 3" of ceramic blanket, but I think the efficiency of the blanket would be compromised if I compressed it with cladding.

2) When transitioning from the ceiling arch to the door arch does it need to be gradual or can it step down (sorry can't think of a better way to describe what I'm asking)?

3) My entry arch will not be touching the oven door or hearth. There will be a thermal break and I plan on placing the flue on the entry arches. I do not have any more Calsil. Can the entry arch sit directly on the concrete hearth or does it need to have insulation underneath?

Thanks in advance for the help... I plan on finishing the vault this week and move on to the entry arch and insulation/cladding.

John

1. Your barrel oven is pretty much a semi circle so there won't be much sideways thrust on the lower brick walls. i wouldn't be worrying about cladding or buttressing there, especially as you don't want any extra thermal mass.
2. Normally a straight step down. The end walls should be under the vault rather than outside it.
3. It's the oven you want really well insulated, so no it probably makes little difference if there is no insulation under the entry.

[Laurentius]

Re: A few questions

You clad before you insulate!

[JohnR]

Re: A few questions

David: thanks for the help, I've read a lot of your posts and appreciate your insight.

Laurentius: sorry about that I meant buttress for structural integrity, not cladding for added thermal mass.

I'll post more pics on my build thread, but this picture shows how far up the vault I am on both sides.

Is no buttressing necessary the consensus, or is there another opinion? I ask because I have enough ceramic blanket to cover the whole oven in 2" and then I was going to fill up the enclosure/house with vermiculite. But if buttressing might be needed then I can put foamglas or calsil boards along the sides and back with some concrete block for buttressing and cover the top of the vault with 4" of ceramic blanket and forget the vermiculite.