Nowadays, slop roof consists of steel column and beam or steel truss and purling, and connected with existed building by concrete beam cast in place, is being used commonly in this project.

目前，在全国各地的“平改”项目中，普遍采用轻屋，由、梁或桁架及檩条成，通过浇筑混凝土卧梁将新增轻屋与原有混凝土连接。