Wood siding on oven wall

[BANTAR1000]

I've got my pedestal, the dome and a fireplace on my oven finally built.  (mostly)  There was a failure to communicate on my part to the guys helping with the fire place.  But, I love the way it turned out so I'm now changing my design. I'm going to build a 'dog house' around the dome, but my plan is to start that dome in the center of the side of the fireplace so I will have the fireplace visible.  If I build the doghouse and a frame roof with metal studs is there a reason I can't put wood siding around that since it will be so far away from the fire?  In my drawing, I would put the wood siding where the question marks are and all the way around the dog house. 

[Jon in Albany]

with 20/20 hindsight, I think I would have used steel framing on the enclosure face with the oven opening and near anything that framed the chimney. In my setup,, near the chimney is the only part of the enclosure that sees any heat, and it isn't much.

Mixing and matching may not be up to building code by you, but I checked with my local bldg office and my only constraints were distances off a building and property lines. Framing in the roof with timber would have been much easier. And wood is easier to buy, cut, and put together too. Maybe concrete board all around or just up front. Plywood would have been OK for sure on 3 of the walls.

So, if everything is very well insulated plus an air gap, I wouldn't expect the wood framing on 3 walls and the roof to see anything higher than typical attic temperatures.

My 2 cents...

[BANTAR1000]

Jon,

You just made me feel so much better!  My plan was to steel stud frame everything and Durarock the walls.  But now, I may just use wood framing.  I intend on wrapping the dome with fiber blanket and refractory cement, then pouring vermiculite all around it inside the 'dog house.'  Since I won't have an overhang over the oven door, I don't think anything will actually feel any real heat.  Now I just have to decide what to use for the siding.

Two questions for you:

1. What do you mean by an air gap?  I'm planning on using tin roofing on an a-frame.  Can the ridge vent work for this? 

2. The ceramic fiber blanket looks and seems to be the same stuff they use to insulate a water heater sold at lowes...  Do you know if that stuff sold at lowes will work?  Thanks again.  -John

[Jon in Albany]

For the air gap, I didn't mean a ridge vent for a roof. I meant a space between all the insulation and the timber framing. I'll try to explain it better.

say you've got 40 inch diameter dome, then 3 inches of insulation, then 2 inches of loose perlite - that's a total width of 50 inches. The dome plus insulation on both sides. If the distance between the inside of the timber studs is 54 inches, there's a 2 inch air gap between the studs and the insulation on each side. With the stuff I have around my dome, I think the roofing sees more heat from the sun on black shingles than from the oven.

I used a ceramic fiber blanket I got from a kiln place. I can track down the name if you need it. It is good to something like 1600 degrees. I'm not sure what you were looking at in a Lowes but make sure it is good in the temperature range you expect. The wood oven is going to get a lot hotter than a water tank. All that blanket insulation kind of looks the same. The design range is what matters.

[BANTAR1000]

That makes total sense.  Yes please, I’d love to know where you got the blanket!

Also, is there anything holding the ‘loose’ perlite? How do you keep that 2” away from the framing?

[02ebz06]

For the air gap, I didn't mean a ridge vent for a roof. I meant a space between all the insulation and the timber framing. I'll try to explain it better.

say you've got 40 inch diameter dome, then 3 inches of insulation, then 2 inches of loose perlite - that's a total width of 50 inches. The dome plus insulation on both sides. If the distance between the inside of the timber studs is 54 inches, there's a 2 inch air gap between the studs and the insulation on each side. With the stuff I have around my dome, I think the roofing sees more heat from the sun on black shingles than from the oven.

I used a ceramic fiber blanket I got from a kiln place. I can track down the name if you need it. It is good to something like 1600 degrees. I'm not sure what you were looking at in a Lowes but make sure it is good in the temperature range you expect. The wood oven is going to get a lot hotter than a water tank. All that blanket insulation kind of looks the same. The design range is what matters.

I used ceramic blanket as well when I stucco'd my PizzaParty ad previous house.  Got mine from Amazon.
Was cool to touch no matter how hot unless you put your hand on the side right where the fire was, then just warm.

[02ebz06]

That makes total sense.  Yes please, I’d love to know where you got the blanket!

Also, is there anything holding the ‘loose’ perlite? How do you keep that 2” away from the framing?

Here is one on Amazon, good to 2600F.
https://www.amazon.com/dp/B07C51GCSV/?tag=pmak-20

[Jon in Albany]

Similar stuff, I got whichever line of Inswool was recommended from Harbison Walker. Was lucky and had to travel in the area of one of their locations for work. Got the board for under the oven there too.

I kept the loose perlite in place-ish with the pieces I used to form the oven walls. Dumped more on top of the oven while closing up the roof. Again, with 20/20 hindsight, I think I would have just gotten a little more blanket instead. With a 4th inch of that blanket, I can't see the outermost piece of insulation ever getting hot to the touch. If there is exposed brick that could get hot, that's a different story.

[Tscarborough]

Code is 4" airspace between flue/fireplace for wood, with a few exceptions that do not apply in your case.  Wood it up!