When choosing various building systems, architects, contractors, and building owners are faced with having to make decisions about material performance, life cycle cost, finish, recyclability, environmental friendliness, and ease of use. Copper is often the material of choice today, because of its advantageous characteristics in all of these areas compared to other architectural metals.
In terms of longevity and service life, copper architectural systems are known to be long-lasting and cost-effective for roofing and cladding purposes. Many structures in North America feature copper that has been in place for over 200 years, and in Europe there are examples of roofs which have been in service for over 300 or 400 years. Today we expect similar life spans for properly designed and installed copper systems.
Why does copper have such exceptional service life? When exposed to the environment, it forms an extremely durable patina which protects the underlying metal from corrosion, damage, and natural wear. This very thin layer, which can exhibit a range of colours frombrowns and blacks to greens and blues over the life of the material, is the reason that copper performs so well throughout Canada. Patina formation starts immediately on exposure, and there are noticeable changes within six months after installation. The underlying copper is then protected, resulting in a material that exhibits great natural beauty, requires little maintenance and is exceptionally durable.
What about copper and the environment? Most copper specified for architectural installations, whether roofs, wall systems, interiors, or fixtures, is typically manufactured from recycled metal. It previously existed as something else, such as plumbing tube, or electrical wire and cable. As well, when buildings are renovated or restored, old copper materials, regardless of their age, are typically recycled, often recouping much of the cost of new materials. No other metal, much less plastics, or asphalt materials, can come close to matching copper in this vital area. Copper is considered a green metal and not just for its colour.
This copper advantage is important when considering what type of roof or cladding system to feature on a building. Even typical single-family houses can benefit from a long-lasting, maintenance-free material being used as a roofing system. Compared to other types of architectural metals, copper has an excellent life cycle profile.