20 Apr The Metals in Metal Roofing: What is Copper Roofing?
In another of our series “The Metals in Metal Roofing”, McCarty Metal Roofing Systems of North Carolina explores copper metal roofing.
Copper is generally recognized as one of the most attractive metal roofing options. Unfortunately, it carries a pretty hefty price tag. Copper is the most expensive of the three most popular roofing metals (steel, aluminum, copper – in increasing order of expense). Rarely used over an entire residential roof, copper is mainly used for accents over bay windows, dormers, or other areas where a touch of elegance is desired. Copper is used often on historic buildings, church steeples, cupolas, and the like. Copper is installed in short standing seam panels or sheeting, but there are some copper shingles available as well.
Classic’s Oxford Shingle is available in copper, an ideal choice for the applications mentioned above, and available through McCarthy Metal Roofing Systems.
Galvanic Deterioration and Stain on Copper Roofs
Sometimes, copper is used as a flashing material in conjunction with other roofing materials, but that’s not a recommended use with aluminum or steel roofing, not only because most residential metal roof systems come with their own preformed flashings, but also because if copper is left in direct contact with a dissimilar metal, it will speed up the deterioration of the other metal through galvanic action. Besides, as the copper becomes patinated, the water runoff has a tendency to stain other metals, brick, concrete, and almost anything else with which it comes in contact. Therefore, it’s important to understand where the water runoff over a copper portion of a roof is being directed and how it is channeled off of the roof. As an alternative, and to solve this problem, lead- coated copper is sometimes used as a replacement for pure copper. This is being done less often, though, due to the public outcry against anything lead-related in building products.
Copper Patina on Your Roof
Copper is best known for its attractive blue-green, or verdigris patina that forms when left exposed for 8-15 years. The actual length of time to completed patination depends on what is in the air; salt spray in a coastal environment, for example, dramatically hastens the process. The patina is like a barrier against corrosive elements and is part of the reason for copper’s extremely long life. While copper can be treated to speed up or slow down the patination process, or even be purchased pre-patinated, most homeowners elect to allow copper to weather naturally so as to ensure the rich, luxurious verdigris look.
Copper for Long-Life Roofing…All the way Back to Paul Revere
Because copper is relatively soft and malleable, it is fairly easy to work with and usually solders well. Copper is extremely durable and has a very long life—sometimes more than 100 years. Copper has been used extensively for hundreds of years in the United States. One of the first applications was the Massachusetts State House. The copper for this project was one of the first orders for Paul Revere’s newly founded copper rolling mill, in 1801.
The Permanence of Copper Roofing at a Lower Cost
Recent coatings technology has brought homeowners the option of choosing steel or aluminum roofing that has been coated to resemble copper. Finishes are available from bright “new” copper to fully weathered copper, as well as coatings designed to look like copper in varying stages of the patination process. Classic offers several colors along this line on its aluminum roofing systems, giving homeowners an option of the permanence of copper at a lower cost.
Copper Roofing Summary
- Beautiful, extremely durable, easy to work with, easily solderable
- Expensive, runoff will streak or stain other materials, natural patination takes time
- 12 oz. (.016″) and 16 oz. (.022″) are common for pre-formed shingles
- 16 oz. (.022″) and 20 oz. (.027″) are common for vertical seam
- Between 100 and 150 lbs per square.
- Varies but is often around 35%.
Copper Solutions from McCarthy Metal Roofing Systems of North Carolina
Whether you choose to use copper metal roofing as an accent to your bay window or other home feature, or, choose a “copper like” profile from Classic Metal Roofing Systems for excellent durability and a life-time guarantee for your entire roofing project, we can help. Contact us today for a free estimate, and to learn more about the environmentally sustainable roofing products we offer.