Copper Roof Turning Green Chemical Change

The only way to prevent a copper roof from turning green is to prevent this reaction from occurring.
Copper roof turning green chemical change. The gradual slide from appearing as a newly minted penny through its brown black and green phases is an oxide sulfate patina or coating that s. 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. This change occurs as a result of a chemical reaction between the copper moisture and oxygen referred to as oxidation.
Eventually the roof will even out to a brilliant green. This is a chemical change because copper oxide is a substance that was not there before. 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. The exterior of the statue of liberty is made of copper about the thickness of two.
This layer known as a patina is incredibly thin. Copper can also turn gray brown or blue in some circumstances. Colors often include shades of copper green dark brown and turquoise.