These fences must be replaced an average of three times over the course of a typical two-year-long construction project. Moreover, they obstruct sightlines into construction sites, making already perilous jobsites still more dangerous.
颱風頻繁的台灣，一般建築工地以鐵皮當圍籬，常有被狂風暴雨吹倒、造成傷害之虞；兩年施工期間平均得更換 3 次圍籬，甚至因為封閉使圍籬內的工地成為安全死角。