Wide, light, thin wall due to the rigid polyurethane foam also acts as a structural material, making the overall structure is light weight, span, the advantages of high load. Moreover, xps extrusion board, its unique closed cell and high resistance to gas diffusion makes these have superior long-term insulation properties, its thermal insulation properties of sustainable 20 - 50 years or more. Polished 1) insulation board joints uneven application at coarse sandpaper, action is gentle circular motion, do not sand along a direction parallel to the plate joints. 2) promptly cleaned from dust with a brush polished.