Prior to decoration the glass should be protected from any sandpaper damage whilst rubbing down etc.
Washing down of the window should only be carried out with a Non-Abrasive cleaner such as diluted washing up liquid.
Regular decoration depends on the type of coating applied and the level of exposure.
For instance a product such as the Teknos microporous paint system we would expect to last a minimum of 5 years in
normal exposure conditions.
However in exposed or coastal areas this is likely to be reduced.
The joinery should be visually inspected annually and maintained as found necessary.
The suppliers data sheet should be followed in all applications.