Scaffolding poles is what we use but also get some plastic pipe to use as a sleeve to cover them (i forget the size right now). That does two things, it stops any marks from the metal poles and makes them easy to wipe the fluff and stuff off, AND makes the rugs easier to load because the plastic pole spins on the scaffold pole. Or, the first lot we had done we had plastic dip coated, but our guys prefer the pipe sleeve ones.