There are many types of oil felt paper, which can be divided into petroleum asphalt felt, coal asphalt felt, low-temperature resistant felt, powder faced felt, sand faced felt, colored sand faced felt, mineral wool paper felt, asphalt glass cloth felt, metal foil felt, hot-melt felt, self-adhesive felt, flame retardant felt, etc. according to the type of asphalt and spreading fabric, tire base material, functional characteristics, etc. Among them, petroleum asphalt felt can be divided into three specifications according to their grades: 200, 350, and 500. Each specification of felt has its specific application scenarios and performance characteristics.

The leakage of asphalt glass cloth and felt mainly occurs at the through wall pipe, bolt, deformation joint, and roll joint. These special areas have poor waterproof base treatment, loose structure, and loose leveling layer closure; The edge of the additional layer of the coil is not tightly closed, and the cutting of the coil is irregular; Poor twisting and compression of the deformation joint waterproof strip, structural deformation, and other reasons cause water leakage at the deformation joint; The joint rolls constructed successively at the joint of asphalt glass cloth and asphalt felt have been damaged, and the adhesion is not tight, resulting in water leakage. During construction, standardized treatment methods should be adopted according to different special parts. During operation, the roll material should be carefully cut according to its shape, and the edges should be flattened and tightly bonded. After completing the additional layer paving in these parts, careful inspection should be carried out to ensure strict acceptance.