Wish I could vent it horizontally however stove is not on an exterior wall and recent renovations and a new addition would make it very difficult at best to do it. So, I need to figure out how to go through the ceiling into unheated space over ceiling and then up through the roof. My concerns involve possible condensation and grease accumulation in the pipe; having a stack that can survive a grease fire in it; having a safe and solid pipe exiting the roof. The stack would have to extend at least two feet above the roof to be above snow accumulation. I'm frankly not certain that this can be done practically in a safe and sound manner. Would Metalbestos pipe have a place in this project?Thanks for any comments offered.