I work extensively on promoting asphalt shingle recycling, and people often ask what the recycled shingles are used for. As it happens, asphalt shingles are made up of essentially the same ingredients as highway pavement, and they can be added to paving quite effectively. In fact, the use of recycled asphalt shingles in municipal or state highway paving projects is quite common, and GAF has been working for many years to promote it as an excellent use for the material, after it has served a long and useful life on the roof. Often used at 5% by weight (or sometimes more in sub-base layers), recycled asphalt shingles can even help reduce the cost of paving projects and may bring other performance benefits as well.
However, as virgin asphalt prices have eased with the drop in crude oil prices, there has been less incentive to use recycled asphalt shingles in municipal paving, and the demand side of the business has dropped accordingly. At the same time, the residential paving business is a very large, yet seemingly untapped, possible outlet for the material. It would seem that a driveway, which doesn’t have the same load or usage challenges as a highway, would be a great place to put recycled shingles to work.
To test this, I recently got my own driveway paved with a blend including recycled asphalt shingles. Like any emerging market, this wasn’t easy to set up and required me calling around and drawing on our extensive network developed over many years promoting asphalt shingle recycling. However, eventually I was able to do it, and I can report that the project went well. Shingles were blended into my driveway at 20%, much higher than the normal 5% used for highways. Overall, the project was a success. In fact, the paving company I used now prefers the shingle blend because it saves on costs and sets up quickly, allowing a quick on and off the job. Other than that, they saw no difference. As someone familiar with operations in an asphalt shingle plant, I was even able to smell the shingles in the hot asphalt!
GAF continues to support asphalt shingle recycling in all its forms. It’s clear that recycling asphalt shingles into pavement makes economic and environmental sense, but new markets are always needed for any recycled material. So next time you need a new roof, maybe think about how your old one could be made not just into your street, but also into your driveway!