Asphalt Shingle Recycling

Asphalt shingle recycling is the recovery of waste asphalt shingles, mostly by grinding them into small particles for use in asphalt pavement. Asphalt shingles are among the most widely used roof coverings in North America, so they generate a large waste stream when roofs are replaced.

Size of the waste stream

A study commissioned by the US Environmental Protection Agency in 2007 estimated that the United States generated about 11 million short tons (roughly 10 million tonnes) of asphalt shingle waste each year, most of it sent to landfill. The waste comes from two sources:

• Tear-off shingles removed during reroofing, which make up most of the volume.
• Manufacturing scrap, such as trimmings and rejected shingles, which is cleaner and easier to recycle.

Use in pavement

Shingles contain asphalt binder, mineral granules and a fibreglass or organic mat. Ground shingles, known as reclaimed or recycled asphalt shingles (RAS), can replace part of the virgin asphalt binder and fine aggregate in hot-mix asphalt for roads and parking areas. In 2019, US asphalt plants accepted an estimated 1.1 million tons of reclaimed shingles.

Processing

1. Collection at transfer stations or directly from roofing contractors.
2. Sorting to remove nails, wood, underlayment, flashing and trash.
3. Grinding to a specified particle size.
4. Testing, especially of tear-off shingles, for contaminants; some older roofing products may contain asbestos, so screening is an important step.

Barriers

Recycling depends on nearby processing facilities, asphalt plant demand, specifications from road agencies, and landfill tipping fees. Where landfill is cheap or processors are distant, shingles are still commonly landfilled.

Context

Construction and demolition debris is a large waste stream; the US EPA estimated about 600 million tons were generated in the United States in 2018, with just under 145 million tons sent to landfill. Asphalt shingles are one of the materials the EPA tracks in that stream.