Going Green: All About Copper Patina

As I said in the last blog, copper roofing is becoming popular again. I say “again” because looking back at history, it’s been used for many centuries as a favorite roofing material.

The patina that forms on copper roofs is a result of weathering and changes in the chemical composition of the metal. It’s a process of oxidation that happens over time that turns copper green. Other metals can acquire a patina as well. Even old wood furniture can get a sheen of oxidation in time.

Metal Master Shop aged copper roof on churchUneven Changes

The patina develops based on exposure to oxygen, water, and chemicals. Because of these varying conditions, the patina will form unevenly.

As you can see in the picture, the patina is only visible in certain areas. The top of the roof will have the least amount of standing water because of the incline, for example, so it may turn green more slowly than other areas.

Likewise, depending on the climate, patinas will develop faster or slower. As with everything else in Miami, we move fast! A patina will form on a copper roof here far faster than it will in a drier climate.

Although this process takes time, it starts immediately after the copper is first exposed to the elements.

If you want to speed up the process or assist it in developing more evenly, there are some chemicals that can be painted or applied to the roof. But this artificial enhancement doesn’t always achieve the same look as a natural progression.

Not just a pretty face

While many love the look of a copper roof with a full patina, it’s also very beneficial for your roof. The patina is like an extra protective layer of armor against the elements. The very things that change the copper surface initially, make it stronger against those same corrosive materials.

This “armor” isn’t just chemical, but physical as well because the patina literally adds layers to the roof, making it physically thicker.

As you can imagine, in the Miami, Florida weather, anything you can do to make your roofs more resistant to the elements is a good thing! It will help your roof last longer than if you routinely clean the patina off.


Quite frankly, if you don’t like the look of patina on a copper roof, I would suggest that you get a different metal. We have some that aren’t copper but look like it, so they will have the same appearance as a new copper roof but won’t develop the patina as time goes by. That is a smarter option for those with a different style in mind for their property.

But no matter what you are looking for, Metal Master Shop has what you need.


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