can run single wall pipe to the wall of the building, then if the wall that you go through is flammable, triple wall pipe through the wall, double wall pipe all the way up on the outside.
That double wall stainless is not cheap. that's what I got on the outside.
I went through this site for directions and all the pipe I needed.
https://www.woodlanddirect.com/chimney-and-stove-pipe/?msclkid=cbdb0ce2eace147645d65349f25c80cf&utm_source=bing&utm_medium=cpc&utm_campaign=Chimney%20Pipe%20-%20Old&utm_term=Chimney%20Pipe&utm_content=Chimney%20Pipe%2FG
