I bought 6 feet of ABS pipe today. It will have to wait a while before I get up to the roof again. It's cold and I'm sick. Actually have been for a long time. I'll be going into the hospital next Monday. Hopefully for a short stay. No sympathy requested. My body is hurting, but my mind is happy. And this hobby doesn't take a lot of physical strength. If I'm lucky I'll have my laptop and internet while I'm in the hospital.Adding some height to roof mount by fiberglass/PVC pipe is a good idea.
Any addition to height will improve the range. Each foot of height counts.