Matteo Lundgren

It looks like Ernie used single wall stove pipe for the exit out the door. That pipe must get really hot if its single wall. Wondering what your experience is with that single wall, double wall or triple wall directly out the doorway smoke exit.  I got his plans for the two chamber Earthen oven the biggest chimney pipe opening he recommends is 6 inches.  If I were to use a triple walled stove pipe to exit the top of the cob doorway would that be over kill?  Since triple walled pipe is 8 to 10 inches wide from the outside I wonder if thats too big for the archway to support? Basically I am deciding between buying 4 inch insulated pipe, 5 inch insulated pipe, or 6 inch insulated pipe and wanted to hear all your thoughts prior to make that purchase