I am about to replace a chimney with a stove pipe due to snow issues knocking over the old chimney from sliding down metal roof. Using 3/8" thick single wall pipe, 8 3/4" O.D. Pipe will run out through block wall and up through roof overhang about 12" from outside block wall. How close can / should I run the new roof sheathing up to the pipe due to heat related issues? New sheathing will be covered with metal to cover existing square cut-out from old chimney block. Also - is there something I should wrap the pipe with, or cover the sheathing with to protect from heat? - Chimney is used at cabin with wood burning stove, maybe 12x / yr. Any thoughts/ discussion appreciated. Thanks!
Use double wall pipe. Please! With double wall pipe it's much safer because the inner wall will stay hot enough to give excellent draft and keep creosote buildup to a minimum and you are able to run the pipe closer to combustibles.
Use the directions that come with the pipe for clearances.
"The physician can bury his mistakes, but the architect can only advise his clients to plant vines." -- Frank Lloyd Wright
I hear you about the double walled, but the materials were available for free, and it is a "shop made" fab fit - so no directions. We're going to put it together in pieces, welded, and concrete it into the ground inside the existing chimney block below the ground level. Hopefully it will work OK and draft fine - Im not ventillation expert, just trying to find something that is more structurally sound and shear resistant to snow load/slide than chimney block...