粉剂防水材料为建筑拒水粉，其化学成分为脂肪酸钙和氧化钙的复合型白色粉状物，其中脂肪酸钙的包裹体覆盖量越高其憎水性越强。多为整体刚度好，变形小的各类钢筋混凝土屋顶板。当结构层采用装配式钢筋混凝土板时，则应在预制屋顶板的支承端处，及与非承重外墙的相邻边处，应在强度等级为 C20的细石混凝土灌缝的上部留有 30mm 深的凹槽，并灌入建筑拒水粉。现浇保护层必须设置分隔缝，设置部位应在屋顶板的支承端及屋脊檐口等处，分格面积不大于 36m 2 。保护层上部宜做表面分隔缝，间距不大于 1m。块材的保护层可不设分隔缝。
The powder waterproof material is building water repellent powder. Its chemical composition is compound white powder of fatty acid calcium and calcium oxide. The higher the coverage of fatty acid calcium, the stronger the hydrophobicity. Most of them are all kinds of reinforced concrete roof slabs with good overall rigidity and small deformation. When the prefabricated reinforced concrete slab is adopted for the structural layer, a 30mm deep groove shall be reserved at the supporting end of the prefabricated roof slab and the adjacent edge of the non bearing exterior wall at the upper part of the fine aggregate concrete pouring joint with the strength grade of C20, and the building water repellent powder shall be poured. The cast-in-place protective layer must be provided with a partition joint, which shall be set at the supporting end of the roof slab and the roof ridge cornice, with a grid area of no more than 36m2. The upper part of the protective layer should be provided with a surface separation joint with a spacing of no more than 1 m. The protective layer of the block may not be provided with a dividing joint.