Why Does Copper Turn Green?

One of the most popular questions regarding copper roofing is, “Why does copper turn green?” The answer often shocks the person asking the question. The plain, simple truth of the matter is – copper turns green due to corrosion. Just like iron rusts, copper corrodes to a lovely green color.

Nature’s Perfect Waterproof Roof

Patina isn’t dangerous in any way. In fact, it protects the copper from further corrosion. It is quite honestly the perfect waterproofing material for roofs, which is why so many people used copper for their roofs 100 years ago. When homeowners remove that layer of patina to expose the shiny copper finish beneath, they’re effectively removing a layer of their roof. The patina process begins once again.

How Long Does a Copper Roof Last?

Copper and stainless steel are the longest lasting roofing materials available today. They last between 60 and 100 years, minimum. Many homes that are well over 100 years old still boast a copper roof today. If you’re able to purchase a home with a nice patina roof that is only 20 or 30 years old, count yourself lucky. You’ll likely never have to replace the roof while you own the home.

Shades of Copper

Copper weathers beautifully compared to other types of metals used in roofing and guttering. Throughout its lifespan, copper goes through a variety of shades of rust, blue, and green. Copper changes to a dark rusty color within its first year. The second, third, and fourth years begin to show shades of green mixed with the reddish copper tones. By the fifth year, your copper roof will be primarily dark green. Years seven through 25 see major differences in shades of green and blue. Copper roofs age 25+ maintain a light blue-green patina for the life of the roof.

Some homeowners confess to choosing copper roofing, guttering, downspouts, and other accessories as a way to add a type of jewelry to their home. Their efforts pay off in the long run because copper ages at a relatively slow pace, taking 25 years to reach full patina. Every year, the homeowner has the satisfaction of seeing their home transform before their eyes.

GSB Services, LLC. is a locally owned and operated company located in Delafield, WI. We specialize in custom sheet metal fabrication, copper guttering, copper roofing, and copper chimney flashing. Our metal smiths love what they do and it shows in their workmanship. Call us any time to discuss your ideas regarding adding copper to your home or business. We look forward to hearing your ideas and creating a solution for you.

GSB Services, LLC
220 Watertown Plank Road, Unit C
Nashotah, WI 53058
262-646-3070

Site map

Copper Gutter - Copper Sheet Metal Fabrication - Ice Dam Solutions - Copper Roofing