I own a two story building with a flat roof. I would like to put a TV antenna on the roof. Even though I have two chimneys, my next door neighbor's 3 story building would block reception to an antenna mounted on either of the two chimneys. His building is about 6 to 7 feet taller than my chimney and only 3 and a half feet away from the chimney. I do seem to have a non-used vent pipe towards the back of the building in the middle of the roof (right by the trap door that leads from the 2nd story porch to the roof). The vent pipe is 2" in diameter and sticks about 9 inches off of the roof. The top is covered in tar. There is also no plumbing underneath this vent pipe. The pipe does not seem to move when I push on it. Is it safe to mount to such a pipe, or can it cause damage to my roof? Or are there other alternative mounting areas. I don't really want to mount to the side of the building.
Thanks