Why do they put the old film back on the window after removing it?
This is to soften the adhesive from the old UV film, making it easier to remove. It’s really important to apply UV film to a clean surface to get a good finish.
How long does it take to complete a window?
That often depends on quite a few factors: how old the UV film is; the thickness of the pane(s) of glass; and the condition of the windows. If the film is very old it might not come off in one piece. If the film breaks up, it takes much longer to remove. If the glass is very thin, more care needs to be taken when removing the old film as too much pressure on the window may cause it to break. Windows in poor condition will take longer to clean than windows in good condition.
Will this stop items from fading?
No, not completely. This will only stop the damage caused by ultraviolet radiation. Objects still need to be protected from visible light which also causes fading and damage. This is the reason we also utilise sun blinds and shutters.