I'm installing a dayton propane heater in an a frame cottage. The installation instructions require the exhaust pipe to rise above the roof peak. Heater is located near an outside wall (the lowest point of the A frame). If I were to run the pipe straight up, it would have to stick up 20 ft in the air. Pipe is metal 4 inch double walled metal exhaust pipe. Is it safe to run the exhaust pipe diagonally through open space - strapped to the diagonal a-frame ceiling, but not touching it, then penetrate the roof near the ridge?
This would require two 45 degree turns.