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Copper Creates Striking Wall Cladding Designs

Copper’s long-lasting, lightweight qualities help make durable wall panels

Cda Oct18 1

What started primarily as an architectural roofing material is now increasingly making its way down the façades of buildings. Copper wall cladding is becoming extremely popular in North America as builders adopt the technique for multiple architectural purposes.

While man’s first metal was originally used for its exceptional malleability and formability, its versatility as an architectural material has increased the number of roofing and siding options available for new construction and renovation projects. Today’s material decisions typically rely on three components: aesthetics, performance and price. Because of these qualities, designers are more frequently turning to copper for their wall cladding projects.

In many ways, copper wall cladding systems can be similar to copper roofing systems. Traditionally they have been generally installed over a continuous nailable substrate which is covered with 30-pound asphalt saturated felt. Rosin-sized building paper is laid over the felt to keep the copper siding or panels from bonding to the felt.

In recent years, the copper industry has also seen a number of nontraditional systems be adapted for use with copper and copper alloys. These include a number of engineered systems from a variety of U.S. and foreign manufacturers including insulated panels, non-insulated honeycomb panels, copper screen panels and structural wall claddings. Regardless of traditional, adapted system or newer engineered system, the majority of copper cladding systems can be formed from sheet material, with many pre-manufactured and transported on-site.

Increasingly Popular

Wall cladding has become increasingly popular over the past decade, several of the 2018 North American Copper in Architecture (NACIA) winners were recognized for their stunning use of copper or copper alloys in wall cladding installations. For example, the Holbrook PreK-12 School in Holbrook, Mass., was cladded in 11,500 interlocking, 18- to 24-ounce, pre-patinated copper panels, covering over 33,000 square feet of the building’s envelope. Covering the entirety of the school’s front curve, copper panels clad nearly 50 percent of the exterior surface.

Many designers, such as those who worked on the Holbrook pre-K-12 School, work with copper cladding for its ever-evolving beauty. Copper reacts when exposed to the elements; but copper isn’t damaged, it just changes colors and develops an incredibly durably and protective patina layer. As copper ages it naturally evolves, turning from bright to iridescent brown, then maturing to a uniform, greenish patina. It should be noted that, as compared to a sloped roof, the patination rate for a wall cladding application is much slower, and indeed will never achieve the complete even green tone of a mature roof installation.

Weathering is a result of the interaction between the metal and the environment. Even in harsh and industrial areas, copper provides a durable architectural solution, but is likely to oxidize or patinate at a faster-than-normal rate due to higher concentrations of pollutants and moisture in the air. Because the red metal naturally forms a tough oxide/sulfate coating as it ages that resists corrosion almost indefinitely, it’s one of the most cost-effective wall cladding materials.

The American Copper Buildings in New York City also feature an incredible use of copper wall cladding. The two towers are adjoined at their closest point through a sky bridge, giving the construction a lively dynamic and making it appear they’re “dancing” alongside the East River. To accent the architecture, the design team developed a copper and glass façade with 4-mm-thick copper-composite panels, installed without additional finishing to allow the structures to patina naturally and evolve over time. The once shiny orange copper continues to visibly weather, giving the facade a darker patina that will eventually age to a greenish shade.

The benefits of using copper don’t end once construction is completed. Its life cycle costs are further reduced by its recycling value. Architectural copper is 100 percent recyclable and therefore retains almost all of its primary value. In commercial and residential projects today, green design in the form of recyclability, sustainability and energy efficiency are all key features of a successful project, all of which happen to be among copper’s most enduring qualities.

Stephen Knapp is director of sheet, strip and plate for the Copper Development Association. To view more examples of how architects and designers are incorporating copper in today’s building wall cladding systems and more, visit www.copper.org.