How does the extruded board prevent water molecules from entering the board?

The thermal conductivity of XPS/extruded board is less than or equal to 0.028w/mk, which is much lower than other insulation materials, so it has the characteristics of high thermal resistance and low linear expansion rate. It is generally suitable for roof thermal insulation system, freezer, thermal insulation inside and outside the wall, and the effect is very good. As a good thermal insulation material, water absorption is an extremely important technical indicator. High water absorption will result in poor thermal insulation performance. XPS board has a complete closed-cell structure. There are no gaps on the front and back sides of the board, so that the moisture generated by water leakage, condensation, water freezing, and thawing cycles cannot penetrate, so it can effectively prevent the entry of water molecules. Therefore, it is impossible to cause the board to age, and it has almost the same life as the building.
When it is applied in buildings, it should be decided according to the local high temperature and low temperature conditions over the years, and choose insulation materials of small economic thickness to ensure that the energy saving requirements are met within the specified service life. Under the condition of satisfying the thermal insulation effect, thermal insulation materials with small thermal conductivity should be selected first, which not only meets the design requirements, facilitates construction, reduces transportation costs, and takes up less space.