Metal Roofing Recycling

Metal roofing materials, including aluminium, steel, copper and zinc, can be recycled repeatedly without losing their essential properties. Scrap from new production (offcuts and trimmings) and from demolition (old panels, flashings and gutters) has value, so it is commonly collected and sold to metal recyclers rather than landfilled.

Aluminium

Recycling aluminium requires only about 5 percent of the energy needed to produce new aluminium from ore, an energy saving of up to 95 percent. About 75 percent of all aluminium ever produced is still in use, which the International Aluminium Institute's 2020 data put at nearly 1.5 billion tonnes. The Aluminum Association reports recycling rates of up to 90 percent for aluminium in building and automotive markets.

Steel

Steel roofing is made from steel coated with zinc or zinc-aluminium alloys and usually painted. It is readily separated magnetically from mixed demolition waste and recycled through steelmaking. Recycled steel content in new coil depends on the steelmaking route.

Copper and zinc

Copper and zinc roofing have high scrap value and are usually salvaged when roofs are replaced. Copper roofs can last for many decades; InterNACHI's life expectancy chart lists copper at 70 years or more.

Coatings and contaminants

Paint coatings, sealants, underlayment residues and fasteners are removed or burned off during remelting. Separating different metals (for example, copper flashings from aluminium panels) improves the value of scrap.

End of life versus recycled content

Two different measures are often confused:

• Recycled content: the share of recycled metal in a new product.
• End-of-life recovery rate: the share of old roofing collected and recycled when removed.

Both influence a product's environmental footprint and are reported in Environmental Product Declarations, which may credit recycling at end of life depending on the rules followed.

Practical recovery

On reroofing jobs, metal is often stripped and kept separate for scrap. Long service life is itself a sustainability factor: InterNACHI lists metal roofs at 40 to 80 years, which reduces the number of replacements and the waste they generate over a building's life.