以沥青油毡用于平屋面,俗称二毡三油一砂、或三毡四油等,已有百余年历史。从初期至今在产品质量的不断提高,操作经验的累积,以及各方面的配合下,长期以来它很出色地完成任务,一般施工一次使用期达20—30年。 Bitumen tar mats are used for flat roofs, commonly known as two felts, three oils and one sand, or three felts and four oils, and they have a history of over 100 years. From the very beginning until now, with the continuous improvement of product quality, the accumulation of operational experience, and the cooperation of all parties, it has performed outstanding tasks for a long period of time. The general construction period of one use has reached 20-30 years.