The picture here shows the type of flue pipe I will be using on my Quadrafire 7100 install.Where the fireplace is going to set the flue pipe just barely hits the truss..Can I get some kind of flue pipe piece that will offset my pipe to center it between the trusses? The pipe has a collar that goes right at the top of the fireplace that has a flex line that runs outside. Its an air cooled pipe I assume. There is a sticker on the outer flue pipe that has SL348 on it if that helps. Also do I need something where the flue goes between the trusses to keep it off the trusses?