In principle, a distinction is made between work scaffoldings and protective scaffoldings. Protective scaffoldings are either catch scaffoldings or protective roofs. When work has to be performed in elevated workstations (in particular for extended periods of time), scaffoldings should be used instead of ladders. Depending on the purpose of use, the duration of work and the height of potential falls, a range of work scaffoldings may be used: fixed scaffoldings, travelling fixed scaffoldings, gantries, metal scaffoldings, trestles, bracket-type scaffoldings , suspended scaffoldings, auxiliary scaffoldings and step ladders. In all cases, the scaffoldings must be expertly installed, must be stable and capable of bearing loads. If necessary, scaffoldings have to be anchored in the ground.