Stove pipe through roof questions.

[Fluke216]

Looking for some clarification here. There's two images here one shows a ceiling support box and one doesn't. Question is do I need one or not? The wood stove is in sauna want to pipe up through roof, roof is low slope 1/12 with 2x8 rafters that will have rockwool inside a foil barrier underneath and tongue and groove boards. The one images shows a ceiling support box the other shows class A double wall pipe with I assume 2 inch clearance around it. Are both of these acceptable methods? Thanks for any info or recommendations.

 

[Burnin Since 1991]

View attachment 349088View attachment 349089
Looking for some clarification here. There's two images here one shows a ceiling support box and one doesn't. Question is do I need one or not? The wood stove is in sauna want to pipe up through roof, roof is low slope 1/12 with 2x8 rafters that will have rockwool inside a foil barrier underneath and tongue and groove boards. The one images shows a ceiling support box the other shows class A double wall pipe with I assume 2 inch clearance around it. Are both of these acceptable methods? Thanks for any info or recommendations.

Right in the middle of the directions is your answer. "If clearances are large enough not to require shielding, extend pipe 2" below ceiling." I have the install on the right, excluding the rubber boot, though I was required to extend the double wall pipe 18 inches below the ceiling. Unfortunately, the ceiling support box wasn't a thing in 1991. I would go with the ceiling support box on a 2/12 roof. Requires less double wall chimney pipe which is a lot more expensive than stove pipe.

 

[stovelark]

The diagram on right has the adj roof support supporting the pipe instead of the ceiling box. Both would probably be acceptable, but the ceiling support box is generally more aesthetically appealing to people.