Americans discard about 15 million tons of asphalt roof shingles a year, but old roofs can be ground up and put straight back into the roads people drive on

When an old roof is ripped off a house, it may look like a pile of junk, but some of those used shingles can get new life under the wheels of cars and trucks. The U.S. Environmental Protection Agency's Life Cycle Inventories of End-of-Life Pathways of Construction and Demolition Materials estimated that approximately 15 million tons of asphalt shingles were disposed of annually in the United States, based on data centered on 2018, the same year the report's breakdown reflects: an estimated 13 million tons were landfilled, and an estimated 2 million tons were recovered for further use. That makes old roofing a potential source of material for roads.

An old roof can become road material

Asphalt shingles contain asphalt, mineral material, and other components used to make roofing products. Once suitable shingles are taken from a building, they can be processed into recycled asphalt shingles, or RAS. This material can then be used in asphalt pavement mixtures, rather than being sent to a landfill altogether.


The EPA’s 2017 report, The State of the Practice of Construction and Demolition Material Recovery, states that the hot-mix asphalt paving industry is the primary market for recovered non-asbestos asphalt shingles. The report also explains that material recovery can mean recycling, reuse, or energy recovery, depending on the material and how it is ultimately used. However, there’s an important catch. Old shingles can’t just be pulled off a roof and thrown on a road. Roofing material must be collected and processed, and the material used for pavement must meet the requirements of the asphalt mixture being produced. This is especially true for shingles taken from existing roofs, which may contain other roofing debris.

Researchers have put recycled shingles to the test

The idea has also been tested beyond recycling facilities. In 2015, a peer-reviewed study titled ‘Performance testing of asphalt pavements with recycled asphalt shingles from multiple field trials’ published in the Construction and Building Materials journal looked at recycled-shingle asphalt mixtures from field projects with seven transportation agencies.

The researchers tested the mixes for several pavement properties such as permanent deformation, fatigue cracking, and low-temperature cracking. Their study found that pavements containing RAS could be successfully produced and met state agency quality requirements in the studied projects. At the same time, the results explained why the details of the mix matter. According to the researchers, factors like the size of RAS particles and the amount of RAS used could impact pavement performance. The point is not that all old roofs can automatically be turned into roads. The point is that properly processed roofing material can be used in asphalt mixtures when the mix is designed for it.

The biggest opportunity may be what gets kept out of landfills

The EPA figures explain why this kind of recycling has attracted attention. Those numbers describe one year, not a current annual total, but they do show the big difference between the amount thrown away and the amount recovered at that time. The EPA’s material-recovery report also says recovery is impacted by practical considerations including economics, local policies, available markets and transportation distances. In some places, those conditions can make recovery more attractive than disposal; in others, they can make recycling harder to accomplish. An old roof may have done its job, but the materials in it can still have value. With proper processing and quality controls, some of those materials can move from a demolition site into a completely different part of daily life: the roads we drive on.