Concrete board as outer structure over Casa Oven?

[jengineer]

You can get excellent tips and techniques by looking through the MHA web site. Take a look at their transition from the oven to the throat of the vent area - CHAMFERED. This has been discussed previously on this board. It helps to turn the flow. One thing to remember is that the ovens made during the annual meeting are torn down after they are used - so no insulation. One thing I like about the reverse flow or squirrel tail set up for the chimney is that you have extremely hot gases flowing over the dome radiating heat back into the structure. I would heavily insulate the horizontal section.

If you do this you would be the first one on this site to do it. That means lots of pictures please.

[dmun]

I think the squirrel tail oven is an unproved idea. The flue gases may help to heat the dome top (which is the hot part anyway) but they will certainly help cool it down in retained heat cooking.

All this becomes moot if you have to run your project past a building inspector. A 30 degree bend is the max allowed by building code: it's the biggest angle you can get a flue cleaning brush past.

Can your reposition your oven entry so it's closer to where the flue needs to end up?

[Barberque boy]

This will probably be the path I go down unless some body here has some really bad feedback. I figure the top of the dome will help heat the flue for draft. But there's that 30 degree angle rule, although the dome dose roll nicely. Yes I would like to imitate their(MHA) throat and venting. My chimney will probably end up going ten feet to meet roof line tolerances. I would transition to S/S once I could go straight up......thanks

[Barberque boy]

Dmun sorry I over lapped you, I don't think there's any room to move the entry. I hadn't thought about the ovens ability to cool quicker also. There wont be any building inspectors, I've kept it unattached, but still do not want to violate any basic principles that would cause future problems. What do you think about doubling the fire brick on the underside of the flue where it travel over top the dome. this could accomplish two things. insulate the dome and change the angle of the flue. I had also thought of taking clay flue liners and laying them over at an angle instead of the bricks the MHA showed . ...thanks

[james]

You can use two sets of Simpson Duravent 30º (and still meet code and the installation instructions), to get a steeper angle -- which will make your hipped roof lower (a sharper angle) and it might help you get the chimney where you want it.
James