Look at the installation: three-point production, seven-point installation, if you do not pay attention to the installation standards, it may cause deformation of doors and windows in the future.

The coefficient of thermal expansion of pvc windo is almost 6 times that of steel, so there must be an expansion joint between the window frame and the wall to prevent thermal expansion and contraction or the slight settlement of the house from deforming the doors and windows.

At the same time, in order to ensure the performance of waterproof, heat preservation and sound insulation, the expansion joints must be filled with elastic materials and then sealed with sealant.

The price of these materials is relatively high, and the quality varies greatly. When installing, take care to prevent cutting corners and shoddy materials.