Basics of copper

• Natural metal family of materials which develops patina naturally over time
• Has been used for centuries
• Ability to form complex shapes due to malleability
• Prestigious appearance
• Durable and corrosion resistant
• Long lasting metal requiring minimal maintenance
• Low thermal expansion values falls in between aluminum and steel
• May be soldered

Copper and sustainability

• Due to its value, copper roofing and wall cladding doesn’t end up in landfills, but is salvaged and recycled
• Copper is 100% recyclable
• Can be perpetually recycled without loss of performance or qualities

Copper facts

• 16 oz Copper > 24 ga> .022” thickness
• 20 oz Copper > 22 ga > .027” thickness

Patina finish – natural

• The natural weathering of copper to the characteristic bluegreen or gray-green patina is a direct consequence of the mild corrosive attack of airborne sulfur compounds.
  • In industrial and seacoast atmospheres, the natural patina generally forms in five to seven years
  • In rural atmospheres, it may not fully patina until 10 to 15 years, or longer
  • In arid desert environments, patina formation may never occur and the copper surface may weather to a dark brown or bronze color

Pre-patinated finish – factory

• Copper mills have developed pre-patinated (aka preoxidized) copper sheet products due to requests from the architectural community
• The patina is a chemical conversion process whereby the top molecular surface of the copper sheet is enhanced and forced to produce a natural patina
• It is very important to have physical samples when choosing a color
• Some pre-patinated sheets have a variation in their color

Precautions

• Gloves should be worn when handling copper, as oils from fingerprints can be quite visible on that material
• Copper specific training for contractors is highly recommended
  • Copper Development Association offers programs

• Refer to building panel transit, jobsite handling and storage procedures document on the ATAS website