Zinc: Cradle to Cradle

Metal has increasingly become the architectural material of choice for cladding institutional, commercial, and industrial buildings alike, due largely to its durability and functionality as a weather envelop, not to mention it’s inherent malleability. Take for example the most well known institutional projects in the Twin Cities: the Guthrie Theater by Jean Nouvel clad in aluminum panels, the Walker Art Center by Herzog and de Meuron clad in extruded aluminum panels, the Weisman Art Museum by Frank Gehry clad in curved stainless steel, and Rapson Hall by Steven Holl clad in copper. Although highly durable, all of the metals mentioned above are extremely energy intensive due to their high melting temperatures: aluminum at 1120° F, steel at 1300° F, and copper at 1983° F.

Increasingly Zinc is being used as an alternative to these more traditional architectural metals due to a number of key benefits. For one, zinc has a relatively low melting temperature of 786° F which significantly reduced the amount of energy required in both its conversion from ore to metal as well as in recycling.

Due to its wide use in a wide variety of products and applications, existing markets for zinc have resulted in recycling rates of over 80%. When taking into consideration its total embodied energy, the production of zinc requires four times less energy than that of aluminum and three times less than either copper or stainless steel despite being a fraction of the cost. Yet like copper, zinc has an incredible durability due to its naturally protective patina. As a result, zinc has a lifespan of up to 100 years in roof applications and up to 200 years or more in exterior wall applications with little or no maintenance required over its lifespan and relatively little energy required to melt it to it’s purified state.