喷涂聚氨酯泡沫已是目前常用的防水隔热材料,据一份国外资料介绍,美国一年喷涂该泡沫的屋面约150万m~2,每年约有8900个油毡屋面用上了这种材料。聚氨酯泡沫主要用于覆盖田屋面,这是因为它能将旧屋面完全封闭,且(?)的潮湿屋面上允许有限水分逸出,具有自(?)燥性。美国的一家国家实验室对此也进行了证实。以1995年为例,在美国用该泡沫覆盖各 Spray polyurethane foam is a commonly used waterproof insulation material. According to a foreign document, the United States sprays a roof of about 1.5 million m2 of foam for one year, and about 8,900 linoleum roofs use this material each year. Polyurethane foam is mainly used to cover the roof, because it can completely close the old roof, and the (屋) moist roof allows limited moisture to escape, with self-(?) Dryness. A national laboratory in the United States also confirmed this. Taking 1995 as an example, covering the foam with foam in the United States