屋面防水层上的积存水,是最常见的事故起因,也是容易预防的。防水层虽然具有抗渗性,但出现积存水时,在很短时间内就会遭到破坏。因此,积存水是屋面防水层以及建筑物及其内部财产的主要危害。它可以 The accumulation of water on the roof waterproof layer is the most common cause of accidents and it is also easy to prevent. Although the waterproof layer has impermeability, it will be destroyed in a short time when water accumulates. Therefore, accumulated water is the main hazard of the roof waterproofing layer and the buildings and their internal property. it can