Are you planning on fastening the heavy pipe down through the roof and tie it in strong enough to be a rigid pole holder or were you planning to use guy wires on the antenna?
Try to avoid using guy wires if you can which will necessitate holes in a new roof or setting pitch pans.
(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net