Glass corrosion is a prominent problem in New York City. And it always comes as an unpleasent surprise for homeowners, who wash their windows just to discover that the glass is not transparent anymore as it used to be.
The leading causes are: the building runoff, city grime, pigeon droppings, construction dust, screens runoff, mineral build-up. All these things if not removed for some time will cause the glass to deteriorate. The extent of deterioration caused by corrosion depends on the time the corrosive substance remains in contact with the glass of the window. With most of the substances, except for construction-related, the process of corrosion is quite slow. But usually window cleaning occurs rare enough for the corrosion to happen. When it happens the haze of the glass is not just dirt on the surface anymore, it is a part of the structure of the glass. Regular methods of window cleaning would not deliver the desirable transparency of the glass.
