Ok, my pellet stove exhaust was installed using simpson duravent. I straight shot thru the wall. I am in the process of siding my house and my contractor talked me into a chimney chase made of wood to get the pellet exhaust above the roof line. Yesterday I spent a few hours onthe phone with different pellet stove dealers. The consensus is I need to convert my simpson duravent 3 inch to 4inch exhaust. I need 25 ft, a 4inch collar, 3 straps and a 4inch rain cap. How does that sound? Also, I found selkirk at Lowes for about 1/3 the price of duravent and Icc exhaust piping. Can I attach my simpson duravent to selkirk? I'll be saving about $275 if I can use Selkirk.