How do you fix a plumbing vent pipe?

Plumbing vent pipe is installed through a cathedral ceiling and metal roof surface there is no easy access into the roof cavity. In an attic after cut off the elbow whose female end contained the remains of the ABS pipe, glued on a short extension and new elbow in the attic, and glued a new plumbing vent rooftop riser into the new elbow. For more information visit at: alliedallcityinc.com