You buy one. Put it in a tripod that you mount on the roof. That's the
challenge. If this vertical is for HF, and isn't a half wave, you will need
a ground system. Putting it up high doesn't usually do any good.
A mast is just a fancy word for a pipe. Might be aluminum and thinner, so
it isn't so heavy.
---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com