What is cold priming oil? What do you mean by three felts and four oils? engineering

Cold priming oil is a solution made by dissolving 10 petroleum pitch or coal tar pitch with softening point of 50~70℃ in organic solvents (light diesel oil, anthracene oil, kerosene, gasoline, benzene, etc.). ). It is often used in the bottom layer of normal temperature waterproof engineering, so it is called cold priming oil. Before laying waterproof linoleum, it can be coated on concrete, mortar, wood and other grass-roots units, which can quickly penetrate into the pores of grass-roots units and be firmly combined with the base surface after the solvent evaporates. The coating film formed by cold priming oil is relatively thin, which is generally not used as waterproof material alone, but as a supporting material for some waterproof materials. The function is to treat the interface at the grass-roots level, which makes the linoleum easy to be laid and creates favorable conditions for bonding similar waterproof materials.

Three layers of waterproof linoleum and four layers of hot asphalt are laid at intervals, which is a common waterproof practice.