Understanding the Color Changes with Copper Roofs

Copper is a popular material for roofs, downspouts, gutters and home decorative elements. It starts with a shiny penny hue and later evolves to green. Most popularly displayed on the Statue of Liberty, this dignified and striking color is not a defect, but a natural process. This change should be embraced rather than scorned—especially since that copper roof may last up to 100 years on your Glendora, CA home. Here is an overview of patina and how your roof color develops.

All about the patina

The patina is the surface layer of copper. When kept inside and away from pressuring elements, it maintains its bronze surface.  While the timeframe is different for every building, copper eventually changes to the brilliant green we see on old pennies and statues.

Copper starts changing when exposed to natural elements. It oxidizes, and the patina begins to break down and thicken. As time moves forward, the patina grows thicker and changes color. It may go through a series of colors from copper to dark brown, turquoise and green. The resultant color depends on the climate and how you care for your copper roof.

Factors affecting patina

How long does it take for the patina to change? People ask because they look forward to this evolution or wish to know how long their roof will remain its original color. The answer depends on several elements including:

  • Surface dirt: Clean copper takes longer to oxidize than dirty copper. If a roof tile manufacturer uses lubricants during assembly, that leaves an additional protective layer on shingles and tiles. This layer remains on the tiles as we build your roof, and it holds on through weather elements to slow down oxidation. When the lubricant is gone, the copper starts its transformation.
  • Environmental conditions: Copper kept perfectly clean and dry will not oxidize, and it never forms the green patina. However, even in a desert climate, that is nearly impossible. In wetter coastal environments, the patina develops more quickly than in a dry and dusty environment. Patinas also develop more quickly where there are contaminants from pollution and volcanoes. Sulfur and chloride are the largest culprits when it comes to turning your copper roof in Glendora, CA green.

Keep in mind that patina rarely develops uniformly. If you install copper roofing at one time and add copper gutters and embellishment later, your roof will likely develop the patina first. Also, the sun angles and dew accumulation may cause some parts of your roof to turn green more quickly than other areas. A saltwater wash helps tarnish the areas that are slow to change.

However, it is better to let the natural process happen on its own. If you try to change your roof color artificially, it is difficult to do that successfully while taking weather and dirt into full account. It is more likely that you will encourage a more uneven appearance and find yourself scrambling to make it aesthetically pleasing again.

Dowd Roofing Co. repairs and installs copper roofs for homes and businesses. Whether you seek a perfect roof color or need shingles replaced in Glendora, CA, we are here for you. Call us today to schedule an estimate.