Metal siding means corrosion... and even if it is covered with paint or zinc-coating, there can still be some kind of scratches, and everything will begin to rust there. Metal is also hard, and if, for example, compare it with vinyl one, vinyl siding is much easier to install. I installed it 2 years ago without problems! Now I am planning to clean it and I search for a vinyl siding cleaner. Can you advise anything?