Roofing Waste and Landfill

Roofing waste includes old coverings, underlayments, insulation, decking, flashings and fasteners removed during reroofing, plus offcuts and packaging from new installations. Because roofs are replaced several times over a building's life, roofing contributes a steady stream of construction and demolition (C&D) waste.

Scale

The US EPA estimated that about 600 million tons of C&D debris were generated in the United States in 2018, and just under 145 million tons went to landfill. Asphalt shingles are one of the materials the EPA tracks in this stream; a 2007 EPA-commissioned estimate put US asphalt shingle waste at about 11 million short tons per year, most of it landfilled.

Main roofing waste streams

• Asphalt shingles: the largest residential stream in North America; recyclable into asphalt pavement where processors exist.
• Metal: aluminium, steel, copper and zinc have scrap value and are usually recycled.
• Single-ply membranes: thermoplastic PVC and TPO can be recycled through programs such as Europe's Roofcollect; EPDM is harder to recycle.
• Built-up roofing and modified bitumen: bulky and often landfilled.
• Clay and concrete tile and slate: durable and often salvaged for reuse or crushed as aggregate.
• Wood shakes and decking: may be reused, chipped or used as fuel, depending on treatment.
• Insulation: some rigid boards can be reused if dry and undamaged.

Reducing waste

• Choosing longer-lasting materials, which means fewer replacements. Published life expectancy estimates range from about 20 years for basic asphalt shingles to 60-150 years for slate.
• Recovering rather than replacing, for example by recoating or overlaying sound low-slope roofs where codes allow.
• Salvage and reuse of tiles, slate and metal.
• Source separation on site, keeping metals, shingles, wood and membranes apart to make recycling practical.
• Accurate ordering and reuse of offcuts.

Hazardous materials

Older roofing products may contain asbestos (in some felts, shingles, cement sheets and mastics) or coal tar. These require testing and specialist handling and cannot be recycled with ordinary waste.

Policy

Landfill fees and bans, construction waste diversion targets and green building credits encourage recycling. Local availability of processors largely determines what is recycled in practice.