My late father used to use chain link fence top rail tube, one end is swaged if you want to put 2 lengths together, I believe they are 10 feet long each, putting 2 of them together may be a bit floppy even if you drill and bolt them together, but one 10 foot section on a single story house should put most any scanner antenna up pretty good, oh he used it for TV antennas, I put my scanner antenna on top, lowered the TV antenna down a few inches, and put the scanner ant. at the top, this last time was on a mast mounted to the gable peak of the up-stairs room, my old room, some good reception up there, on a old RS scanner, before the days of trunked and digital systems.
Just now getting back into it again