Why Do Copper Roofs Turn Green

Usgs for the same reason that iron rusts.

Why do copper roofs turn green.

Just as iron that is left unprotected in open air will corrode and form a. They are 95 chocolate brown with only a few green streaks. Copper that is exposed to the outside environment is more likely to turn green and that is why copper vases and decorative pieces in gardens are often green. I know of condominiums right on the beach at hilton head island which have copper clad mansard roofs and are at least thirty years old.

This process will take several months or years depending on the atmospheric conditions in your area. Both metal and copper oxidize when exposed to oxygen and this is a natural process. Copper roofing is bright pink to begin with and in time it can gain a brownish color and then a nice blue green patina. This change occurs as a result of a chemical reaction between the copper moisture and oxygen referred to as oxidation.

Over time copper will naturally change colors transforming from a shiny brown color to darker browns then blues and finally greens after a number of years. Copper can also turn gray brown or blue in some circumstances. When exposed to the natural elements such as wind and rain copper develops this patina which actually protects and preserves the metal underneath. Copper turns green because of chemical reactions with the elements.

The reason that copper turns green is the same reason the metal rusts oxidization. Copper roofs naturally turn green from exposure to the elements. The patina is due to the process of oxidation and the sulfur particles in the atmosphere. Why copper roofs change color unlike iron that rusts and deteriorates as it ages under wet and airy conditions copper undergoes a chemical change where it actually coats itself with a preservative.