Is a stand-alone vent/oven landing strong

[ThermoJax]

I am planning on building my vent/oven landing area about 1/4 inch away from my inner arch as a heat break. I plan on shoving some insulation board between the two to top it off. I wonder though, if it will be a fatal move, meaning that later I may wish that they were connected for strength. Can anyone comment on the wisdom or folly in not connecting the two?


Tom

[thamnophis]

Re: Is a stand-alone vent/oven landing strong

I have the same question. Doesn't it make at least some sense to break the connection between the two by an inch or three, and insulate with the same material the rest of the oven is insulated with?

[Tscarborough]

Re: Is a stand-alone vent/oven landing strong

I couldn't figure out a practical way to do a structural thermal break, so I just insulated the area extremely well.

[oventhusiast]

Re: Is a stand-alone vent/oven landing strong

Why? I don't see the advantage. You would still need to cut the transition bricks to conform the vent to the dome. (even though they won't be touching)Then you would need to add butress bricks to reinforce the sides of the vent to hold the weight of the chimney (or to keep it from shifting to the side and falling down)! I could be wrong but it seems to me like a case of 'If it ain't broke, don't fix it!
Best of luck to whatever you decide!
Rick

[thamnophis]

Re: Is a stand-alone vent/oven landing strong

The advantage might be that the heat stays where its needed rather than bleeding into the entryway bricks.

I wonder if I could build the front just like the back (we're talking barrel vault style here), adding a square opening with the top layers of brick supported by angle iron.

Then add the ceramic insulation to the front and build another square, angle iron supported structure for the chimney right up against the insulation.

Maybe the draw from the chimney would be less effective with the square opening, but doors would be easier to construct (for me anyway).

There would still have to be a connection of supporting bricks along the edges of the opening between the 2 structures, but it could reduce the connection by 80%+

[Tscarborough]

Re: Is a stand-alone vent/oven landing strong

Look at mine, in sig.

Other than the floor, all that touches is 3/8"x12" of firebrick.

[thamnophis]

Re: Is a stand-alone vent/oven landing strong

Naive question: Is the chimney in front of the door? In other words, does the chimney only function when the door is off?

[Tscarborough]

Re: Is a stand-alone vent/oven landing strong

Correct, although I plan on making an inner and an outer door.

[Tscarborough]

Re: Is a stand-alone vent/oven landing strong

Here is a direct link showing how the smoke chamber is built. I was wrong, there is 32"x3/8" touching, plus the flue itself and and the filler around the flue. The whole area is well insulated, though.

Smoke Chamber

[dmun]

Re: Is a stand-alone vent/oven landing strong

The idea of thermally isolating your entry is something pretty new, and I'm not convinced of it's utility. For starters you don't want to leave any refractory insulation exposed, particularly in your cooking area.

I suppose if you do a lot of retained heat baking it might be worth considering, but the standard design holds heat for a long time. Remember, your entry area gets REALLY hot, not as hot as the dome interior, but there's a lot of heat absorbed there, even with a thermal break.

[Tscarborough]

Re: Is a stand-alone vent/oven landing strong

Exactly, Dmun. I can think of several ways to make a good thermal break, but none that are practical. The simple fact is that insulating materials are either soft or very expensive, so there is no PRACTICAL way to do it, other than insulation around the entry which is sufficient for a home oven.