In the states the vast majority of men working at scaffolding are under 35 . The reason being is you have to build a sidewalk shed first. Then you build the scaffolding on top of the shed . Most men don't last more than 10 years putting up sheds , they end up with back, shoulder or wrist problems . They use frame scaffolding ,which can be put up very quickly and with the frame system you cannot use a harness .