Copper Roof Turning Green Chemical Change

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.

Copper roof turning green chemical change. Eventually the roof will even out to a brilliant green. As the years pass and the roof ages the patina will thicken and change colors. The patina actually protects the copper below the surface from further corrosion making it a good water proofing material for roofs which is why the roofs of so many old buildings are bright green. First copper doesn t turn green it reacts with oxygen in the air to form copper oxide.

The exterior of the statue of liberty is made of copper about the thickness of two. The only way to prevent a copper roof from turning green is to prevent this reaction from occurring. This is a chemical change because copper oxide is a substance that was not there before. This layer known as a patina is incredibly thin.

Colors often include shades of copper green dark brown and turquoise. Copper can also turn gray brown or blue in some circumstances. This is a chemical change because copper oxide is a substance that was not there before.