How to install a double -glazed window in a window opening

Every year, popularity on metal -plastic windows is growing. These windows have many advantages: they are good warm and sound insulator, have an excellent appearance. To install such windows, you must have certain skills and knowledge. Most firms try to save on windows installation. Therefore, they fix the window in the window opening with the help of mounting foam, which climbs in different directions from the window opening. Inexperienced people believe that mounting foam can fully provide hydraulic and thermal insulation of the room. But this is not so. Since the mounting foam does not fit loosely, and there remains air spaces.