Using the right painting techniques; this is a once in 20 year job.
Painting a new metal garden shed is easy and it will last for years providing you follow these simple directions.
Preparation is the key.
What is important to remember is that the single biggest cause of paint failing to provided maximum protection on galvanised iron occurs due to the lack of proper preparation or just no preparation at all!
When the galvanised iron is new it has a fine film of oily grease on the surface to help keep it clean and to protect it whilst it is being shipped and constructed, but this must be removed in order to allow the paint to properly adhere to the surface.
There are a few different ways of doing that, one is to wash the galvanised iron with mineral turpentine, another is to use white vinegar solution in water and another is to use a hot sugar soap mix.