We've been working with an architect on plans for a big custom residence with specs for a large copper roof and other details. A concern arose regarding the presentation of the concept to the neighborhood architectural committee regarding whether the copper roof would be too shiny. Here's how we approached this to ensure approval.
Natural copper will always react with its environment once exposed. Generally speaking, the darker color (gray/brown) that is evident early will even out over the first year of exposure, with slight variances depending on the handling, weather, dust and dirt, and a million other variables that an exterior surface might encounter. It’s safe to say that any shiny, bright copper won’t be shiny and bright for very long. It’s also safe to say that the roof will never be an even, consistent color. The way anyone can tell that a metal is genuine copper and not a painted replica is the inconsistency.
How Patina May Develop
In order to get the house approved as designed, we actually pre-aged some copper to show what it would resemble after some exposure time. It worked. Now that the roof is being installed, questions are arising about the shiny copper that was still visible on the most recently installed sections. The board needed assurance it would all blend together like the parts installed on the section at the left of the photo, which was installed first (and a month before the shiniest sections toward the right). See what caused the questions?
We were happy to reassure the architect and the board that the copper will continue to even out as it ages, that it will stay dark for many, many years; that any green patina that might develop will occur many years in the future and will begin on the flattest surfaces first (“time of wetness” is the technical factor that accelerates a copper patina), and will likely not occur on the fascias for so many decades in the future we’ll all be long gone. Leaving the copper now installed alone will make everyone happiest, look great, and last for a century or more.
If you're considering copper for a roofing project, the material is our specialty. We'd love to answer your questions. Contact us today to learn all about this beautiful, durable roofing material.