Recycling shingles gains notice
by Irwin Rapoport

Of the estimated 11 million tons of oil-based tear-off asphalt roof shingles generated annually in the United States, nearly 10 million are landfilled. However, if fully recycled, they would help reduce oil consumption and greenhouse gases, and lengthen the lifespan of C&D landfills.

Almost 1 million tons of this material are recycled to provide feedstock for asphalt hot mix producers.

“Shingles are just ripe for the plucking,” said Bill Turley, president of the Construction Material Recycling Association (CMRA). “If we used all of it, we could easily set up a system to do it.”

Between 25 and 35 percent of a typical shingle consists of oil. Interest in using shingles is growing and last November at the CMRA’s 4th Shingle Recycling Forum, 381 people attended, compared to 240 at the 2007 forum.

“The reason is simple – the economic benefits are becoming very obvious to many, especially hot mix asphalt plant operators,” said Turley. “They save tremendously when using shingles to replace new virgin bitumen to their mixes, especially since the price of new bitumen has soared in recent years. But plant operators are reluctant to tell the shingle recyclers what value their shingles have, as they are still trying to get the recycled shingles for a very low price.”

Many of the new attendees were representatives of hot mix producers.

“The number of states that accept this material and the amount of research into utilizing it has reached a critical mass,” said Turley, “and now people are beginning to say this is no longer R&D, it is something I can implement myself. While not accepted in every state, asphalt made with recycled shingles is gaining acceptance and there is enough research to back it up so that people who are generally reluctant to try something new are willing to give it a try.”

This is good news to recyclers as the market for shingles now has a solid base from which to expand.

Dan Krivit, a co-organizer of the 4th Shingle Recycling Forum and senior project manager with Foth Infrastructure & Environment, LLC, a Minnesota-based engineering and environmental consulting firm, said, “Given the high oil content of shingles, it can save $2 to $4 per finished hot mix ton. The bidding for paving work and supplying hot mix asphalt for the trucks is competitive and the savings are significant.

“If you multiply the savings against all the tons that are used on roads, millions could be saved and when contracts become more competitive, the savings will be passed along. Recycling shingles makes great economic and environmental sense – it reduces GHG emissions because that is oil that doesn’t need to be refined, purchased and added to hot mix. But the interest in shingles has been much steadier than the rising price of oil.”

He added that in the worst case, roofing contractors or haulers pay the same amount as a tipping fee charged at a landfill to bring shingles to recycling centers, but that many people are now enjoying a 50 percent savings by taking the material to recyclers.

“Ultimately this means jobs and economic benefits that are spread across the system,” said Krivit.

There is an American Association of State Highway Transportation Officials (AASHTO) specification for the use of shingles in hot mix for roads, and the CMRA is pushing a similar specification through the American Society of Testing Materials.

“The Federal Highway Administration is highly supportive of the use of recycled shingles – they know it makes economic sense and has engineering benefits,” said Turley, “but it does not have control over the specifications. They can only advise and advocate their use.”

Krivit is working with states that have approved the use of shingles and those looking to do so.

“AASHTO, which was developed in 1996, was amended in 2009,” he said. “It is generally viewed only as guidelines by the states, but it does provide the context and a peer reviewed starting point.”

The Departments of Transportation (DOT’s) in Minnesota, Iowa, New Hampshire and Wisconsin, he added, have just approved the use of tear-offs in manufacturers specs.

“If the DOT adopts the spec, then the market is ready to take off,” said Krivit. “Since 1986 Minnesota has had a spec for the use of manufacturers shingle scrap, but as of January 1, 2010 the Minnesota DOT now allows, on a permissive basis, tear-offs. The Illinois Tolling Authority has also been working to demonstrate the use of recycled asphalt shingles (RAS) in its hot mix asphalt (HMA) pavements. But Missouri has been the real leader, adopting and implementing its first permissive spec for tear-off RAS in HMA over six years ago.”

Turley added that California and Oregon are looking into allowing tear-offs and that Colorado just conducted a positive pilot project.

Canada is also jumping on the bandwagon. Ontario has a spec for manufactured scrap shingles and is looking to add tear-offs. Nova Scotia has allowed tear-off shingles and British Columbia and Manitoba are considering specs.

Interest in shingles has led to states and cities initiating pilot projects, with at least 24 being planned for 2010 and investments to promote the development of markets for shingle.

“Most governments are trying to be as green as possible and have sustainable purchasing policies and there are examples of states and cities purchasing hot mix specifically to help stimulate the market for tear-offs,” said Krivit, “so if it costs no more than a virgin product, they’ll give a preference to a recycled product. This is the case for copy paper and other products, but it will eventually trickle down to highway departments. They are already purchasing recycled asphalt pavements – the big brother of recycled asphalt shingles.

Asphalt shingle manufacturing plants are doing their part by either recycling the castoffs on-site or selling the scrap to hot mix plants, who bid for the product.

“The same will happen with tear-offs in 5 to 10 years,” said Krivit. “We are close to tear-offs becoming a commodity.”

Turley said it’s not necessary for hot mix producers to unite to purchase tear-offs as the savings are proven and they generally do not want to share any information on production costs with their nearby competitors.

A major barrier to using recycled shingles is the asbestos issue. Prior to around 1975, some shingles were manufactured with asbestos in them. As a result many regulators have been afraid to allow grinding of tear-offs because of a fear the asbestos would become friable.

“But many state regulatory agencies have developed protocols to assuage these fears, and that is helping open up the market,” said Turley, who stresses that asbestos “hasn’t been used in more than 30 years, so there are hardly any shingles with asbestos left out there. A CMRA member has done nearly 100,000 polarized light microscopy tests and has had only 16 hits for asbestos. It’s rare, but regulators are still concerned and they are going to require testing. Fortunately in the states and provinces with higher tipping fees recycling shingles still makes economic sense, despite the testing requirement, to do the tests.”

The United States Environmental Protection Agency (EPA) and state environmental agencies are helping to promote shingle recycling, especially via the CMRA, which is working with the EPA to help spread the word.

Turley said that more and more legislators are aware of the benefits of recycling shingles and working with the industry.

“As a general rule engineers are cautious – they don’t want to take chances until a new product is fully proven. Once they have the opportunity to review the wealth of research and development project results, they often realize that shingle recycling is feasible and can help lower costs of our public highways. We are finding a lot of support.”

He added that while there are other potential market applications that are theoretically possible, the immediate future for shingles rests with hot mix production. However, while some states allow hot mix with recycled content, individual states still insist upon conducting their own pilot projects before giving the green light.

“There is a federal ‘pooled fund study’ led by Missouri DOT, so there is cooperation going on between the states,” said Krivit, “but in general, the states do their own thing. There are legitimate engineering reasons for this – differences between southern and northern climates, which require specific mixes for asphalt.”

Krivit noted that highway pavement engineers use a variety of performance tests, including density and smoothness, to ensure that asphalt made with recycled materials meets the same standards as traditional asphalt mix.