March/April 2013
Asphalt shingle recycling is taking off, with processed shingles providing a cost-effective and high-performing substitute for virgin asphalt in road surfaces. Greater state acceptance and alternative markets could further boost this product’s prospects.
By Ellen Ryan
When looking at road construction as a market for recycled material, you might first think of scrap tires. Growing numbers of cities and states are realizing the benefits scrap tire rubber can add to road surfaces when mixed with aggregate and asphalt to create asphalt rubber. But another ingredient in that mix, the asphalt, can be made from recycled materials as well, collected from asphalt-shingled rooftops across the country and processed back into the sticky goo that binds the solids together.
Asphalt shingle recycling is relatively new in the United States. A few companies started processing postconsumer shingles in the 1990s, but much of the interest in this material dates to 2001, when the Construction Materials Recycling Association (Aurora, Ill.) and the U.S. Environmental Protection Agency (Washington, D.C.) held a shingle recycling forum that attracted about 100 attendees. Attendance at that biannual event is now about 350 people, reflecting the growth in this niche. Companies have recycled shingle manufacturers’ scrap for well over a decade, estimates Jason Haus, CEO of Dem-Con Cos. (Shakopee, Minn.), which operates a landfill and materials recovery facility and recycles construction and demolition scrap, including shingles. After that first shingle forum piqued recyclers’ interest, postconsumer shingle collection started in earnest about five years ago, he says.
According to estimates from the EPA, the United States generates about 11 million tons of scrap shingles annually, of which 10 percent is manufacturers’ scrap. Generally, recyclers accept shingles from houses and apartments of up to four units because their processing falls under state regulations, not federal ones, Haus explains. Road construction is far and away the largest end market for the processed shingles, with nearly all recovered asphalt shingles, or RAS, becoming replacement asphalt binder in the hot mix. Other potential uses of this material, which include cold patch (used to fill potholes), temporary or unpaved road surfaces, aggregate road base, new shingles, and fuel, are mostly just that—potential.
Why would users purchase recovered asphalt instead of virgin material? It all comes back to oil. Modern asphalt is typically a byproduct of petroleum. According to shingle manufacturer Owens Corning (Toledo, Ohio), the asphalt in every ton of recycled shingles contains the equivalent of one barrel of oil. The shingles on a typical house roof contain 20 to 22 percent asphalt, Haus says. “The higher the cost of oil, the higher the value of shingles to recycle, assuming all other market conditions remain constant.” As Marty Grohman, director of sustainability for GAF (Wayne, N.J.), the nation’s largest roofing manufacturer, puts it, “The guy bidding with RAS versus the guy bidding a job with virgin asphalt is essentially bidding with as much as 20 percent less asphalt cost. He’s going to win that bid.” A Virginia research report confirms the potential savings, stating that “according to cost estimates, in 2009, VDOT could have saved approximately $600,000 by using 4 to 5 percent shingle waste in one-half of the hot mix produced.” Recovering petroleum from RAS also means less drilling or less dependence on foreign oil.
Adding recycled asphalt shingles to hot mix creates beneficial properties in the road surface as well. Proponents say recycled shingles make a hot mix that’s stiffer than that made from virgin asphalt, which results in fewer ruts and cracks in the road. Further, “using a shingle mix, your pavement will soften less in a hot climate,” Grohman says.
The Federal Highway Administration (Washington, D.C.), shingle manufacturers, and several trade associations support the use of RAS, recyclers point out. And shingle recycling can help a renovation or paving project qualify for the Leadership in Energy and Environmental Design certification from the U.S. Green Building Council (Washington, D.C.).
For a demolition contractor or construction and demolition processor, the transportation costs, landfill tipping fees, and landfill space required for this heavy, voluminous product are all factors encouraging shingle recycling. “East Coast tipping rates are four times higher than in Michigan,” says Chris Edwards, co-owner of shingle recycler Ideal Recycling (Southfield, Mich.), and West Coast tipping fees are similar, making the economic argument for recycling stronger in those regions. In addition, landfill space is often at a premium. “Try permitting a new landfill pretty much anywhere in the United States,” says Bill Turley, CMRA executive director. Plus, this work generates revenue, they add. “Recycling shingles means six full-time jobs we didn’t have before,” Haus notes.
Shingle recyclers believe the road construction market is more than adequate to consume the volume of used asphalt shingles generated each year. “If there were 100-percent adoption by all states of recycled asphalt shingles into hot mix, they’d use 100 percent of asphalt shingle waste,” declares Dan Horton, founding partner of Asphalt Shingle Recycling Systems (Barrington, R.I.). But the acceptance of recycled asphalt in this market falls far short of that goal.
Processing 1-2-3
Of course, you can’t just steamroll a stack of shingles and call it a highway. First you decontaminate the incoming material, which means pulling out all the other stuff that gets mixed with shingles on roof projects: gutters, wood, tarps, water bottles, and even tools. Training contractors and roofing companies to bring clean loads—or at least separated loads—is important, recyclers say. “If the roofers send in a load mixed with [whatever] they receive from the job site, some recyclers will have them put the wood and paper on top,” Turley says. “That way you can just pull them off.” Further cleanup and sorting can be done manually before the shingles are fed into the grinder. Magnets are remarkably effective at removing the many nails that held the shingles in place.
After decontamination is processing. A grinder—typically a modified horizontal unit—turns the shingles into a granulate that consists of 20 to 40 percent asphalt, about 30 percent aggregate, and about 30 percent fiberglass or paper mat. Many recyclers also screen the product with a trommel after grinding. The exact size of the grind desired depends on the end user’s needs. For hot mix, the material typically must fit through a 3/8-inch mesh. Other uses, such as the surface of unpaved roads, might require a different mesh size.
Grinding can be expensive, mainly because it requires specialized equipment, and the abrasive on shingles quickly wears down the teeth or blades. GAF’s Grohman says grinding recovered shingles costs an average of $20 a ton. Some processors find it’s not cost-effective to send larger pieces through the equipment a second time. For example, after Michigan approved the use of asphalt shingles for fuel in 2010, Ideal Recycling began selling the larger pieces that remain after the first pass through the grinder—about 30 percent of the material—for fuel to a cement kiln.
In some states, asphalt shingle processors must test the incoming material for asbestos, even though asbestos has not been used in asphalt shingles in decades, and less than 1 percent of shingles from the 1970s had it, says CMRA’s Turley. In the states that require it, processors inspect samples at regular intervals (the frequency varies by state) with a polarized light microscope. “We’ve done 1,500 to 1,750 tests and never caught asbestos,” Edwards says. “But it’s a scary thing, so I don’t mind doing the tests.” His company checks for asbestos in every 100th ton of material it receives.
Seeking State Acceptance
Those who have fought for states to accept scrap tire rubber in road construction might recognize the battles the asphalt shingle recyclers are waging. The biggest roadblock, processors say, has been the lack of federal and state transportation department specifications that spell out how recycled asphalt shingles can be used in hot mix. Hot-mix specs vary by state, due in part to climate conditions and the type of stone available nearby for aggregate, so it’s a problem each state’s recyclers must tackle on their own. California, at the forefront of so much environmental innovation, “has not been able to get the right parties in the room to develop a spec for use of [RAS] in roads,” Grohman says, “so tons of shingles are being landfilled there for no good reason.” Michigan allows RAS only in commercial parking lots and driveways, not in state or federal roads. Next door, geographically speaking, Indiana does use RAS in roads, but the weight of the material makes it impractical for Edwards to transport his shingles across the state border, he says. Illinois also allows RAS in roads, but its specifications are different from neighboring Indiana, even though they share a border and, generally, a climate. This checkerboard of specifications and regulations, and the economics of supply and demand, result in vast differences in the volume of shingles recycled from state to state.
Once years of bureaucracy are out of the way, however, shingle recycling can thrive. “In Maine, once the spec was written and mix designs were calculated and the equipment was in place, things took off,” says GAF’s Grohman. “The recovery rate went from single digits to 30 percent in about a year.” The shingle market spiked in North Carolina recently for the same reason. Boggs Paving (Monroe, N.C.) helped get the state’s Department of Transportation and its Department of Environment and Natural Resources on board, working with them for three years, says Phil Hill, the company’s recycling coordinator. His advice: Shingle suppliers or recyclers should partner with an end user—a hot-mix company—and ask their DOT to approach a DOT from a state that allows RAS in roads to find out how it works there. Be persistent, adds Dale Ann Behnen, president and owner of Peerless Environmental Recovery (Valley Park, Mo.). The Missouri DOT moved forward with RAS because it realized that she and another local business representative, Roger Brown of Pace Construction (St. Louis), “just weren’t going to go away.” She also credits Joe Schroer, a field materials engineer with the state’s DOT, who “worked to make shingle recycling a reality for Missouri.”
Missouri might be the state furthest ahead in its use of RAS. One of the first state agencies to allow RAS in hot mix, the Missouri DOT used about 9,000 tons of recycled shingles in its roads from 2005 to 2007—enough to reroof 2,880 houses at an average of 3.1 tons per roof, Schroer says. Today that total stands at about 293,800 tons, just for Missouri DOT projects, and he estimates a similar amount has gone into county roads, parking lots, and other commercial work.
Schroer confirms that in his state, RAS keeps down road construction costs. The producer price index for asphalt binder has about doubled since 2005, he says—from an average of $158 to more than $320—“while the average price per ton of asphalt mixture in Missouri has been somewhat level. … It has reached the point that contractors are using RAS in their mixtures to remain competitive in their bids, resulting in over 150,000 tons used in [Missouri DOT] mixtures for 2011 and 2012.”
As more states jump on the RAS bandwagon, the recycling rate looks like a set of stairs, Haus says. “Every time a state comes on board, we jump in recycled tonnage and plateau until the next state comes online.”
Ready to Recycle?
Those interested in recycling shingles should know the drawbacks as well. The equipment can be costly, for one, though mobile operations like Dem-Con’s will come to your site and process them for you. There’s the need for decontamination and, in some states, asbestos testing. It can take years for state departments of transportation to approve the use of RAS, create specs, and so on. Even when approved, RAS must compete with other materials— reused asphalt from a milled road, for instance—and each state sets a maximum proportion of RAS it allows in its hot mix. In Minnesota, for example, it’s 30 percent; in Maine, it’s 5 percent.
A recycler’s location can determine whether shingle recycling is a worthwhile endeavor. The supply of shingles can vary according to the number of demolition projects, prevalence of storm damage, and even climate change in a particular area. “You need a constant supply to keep the batching plants happy,” warns Mike Taylor, executive director of the National Demolition Association (Doylestown, Pa.). Demand can vary geographically as well. “The market may be very regional depending on local stone as needed in hot mix,” he says. In a “good stone state”—one that has an abundance of nonporous aggregate—recycling might not get far. On the other hand, a coastal state that uses a lot of coral aggregate—which soaks up asphalt—might prefer to use RAS, Taylor says, because “importing hard stone from elsewhere costs money.”
And then there’s access to markets. The National Asphalt Pavement Association (Lanham, Md.) reports the country has about 4,000 hot-mix plants, but they’re not all close to shingle recyclers. “Once you go more than about 20 miles with a tear-off [shingle], I’d say you’re starting to hit the threshold of not making sense to drive raw materials around on a truck,” Grohman says. The NDA’s Taylor confirms that “what kills these plans is the transportation costs—diesel, tolls, labor. ... It only makes sense if it makes money.”
The Road Ahead
If the economic and geographic conditions are not favorable for recycling shingles into hot mix in your region, keep an eye on these other prospective end markets:
Aggregate road base and temporary roads and driveways. “A couple of companies here in Maine use a 50-50 mix of RAS and road base,” says Randy McMullin, environmental specialist with the Maine Department of Environmental Protection (Augusta, Maine). “The 50-50 mix tends to pack down better than gravel alone and is less likely to erode than gravel, is a little cheaper, and can be screened to ½ inch instead of 3/8 inch,” he says. “Paving over it really provides for a good, rugged road or driveway for a long time.”
Cold patch for potholes. “It’s not a big-ticket item,” but it helps diversify the market, Turley says. Taylor lists several advantages of selling RAS into the cold-patch market: “Everyone uses it, you don’t need the hot-mix plant to drag around, and it’s at least as strong as original paving.” Further, cold patch can be stored longer than hot mix because it clumps less, according to the CMRA.
Dust control on unpaved roads. For rural roads, contractors have used RAS ground to a ½-inch mesh or smaller. It’s great for keeping down noise and dust, Behnen says. “You can close your eyes and know exactly when you’ve driven off gravel and onto petroleum-based shingle mix. And you know the dust clouds you leave on unpaved roads? There is none of that with this material. It decreases the dust in the air.” Maine and Iowa have reported good results.
Fuel. It’s not recycling, but burning shingles for fuel is better than dumping them in landfills, some say. The material “burns hotter and cleaner than coal,” says a Midwestern recycler who has created engineered fuel from shingles to replace coal at cement or lime plants. The pilot project has nearly cleared the permitting stage and might go public this spring.
Oil conversion. Recycled Asphalt Shingles Technology (Brentwood, N.H.) is one company that wants to convert the asphalt in shingles back into petroleum. The shingles on American roofs hold some $40 billion worth of oil, Chief Financial Officer Bob Zickell told a local newspaper, though there is debate about its quality.
New shingles. This is a goal, but turning recovered asphalt shingles back into asphalt shingles is not yet cost-effective, Grohman says.
These markets have their potential, but in the short term, road construction is the path to the greatest RAS use. According to NAPA, 26 states were using RAS in 2009-2010. As of January, 20 states allow the use of both pre- and postconsumer RAS; seven states allow preconsumer material only; and four states have pilot projects underway, according to information provided by the Asphalt Roof Recycling Center (Stratford, Conn.). That’s nearly half a country of unrealized potential—not to mention the potential in states that are just getting started down this road. “The paving industry uses 500 [million] to 550 million tons of total materials a year,” Grohman says, “and we’re generating approximately 11 million tons of postconsumer shingle [scrap]. So there’s lots of headroom.” And on the supply side, Edwards says, “there’s a roof on every house.”
If the cost of oil rises again, will that make RAS even more desirable and cost-effective than virgin asphalt? Most say yes, but Taylor says no—he believes the increase in fuel costs will offset the lower cost of the recycled material. “Every ton you provide an end user could go up 45 cents because transportation costs go up, and mobile grinders won’t travel if they have huge diesel costs.” That said, he sees long-term potential for this material. “Bill Turley sees more potential than I do,” Taylor says of the CMRA leader, “but 15 years from now, it wouldn’t surprise me if there’s a big market for this. I’m skeptical now, but I’m open to what the market brings.” Turley agrees on the market’s potential—but it’s also a strong market now, he says. He estimates that about 2 million tons of shingles are recycled annually, though “nobody is positive of the exact number.”
Meanwhile, processors like Edwards are happy to be both making money and saving the planet. “It takes 300 years for a shingle to decompose,” he says, but in five years of operations, his company has saved almost 100,000 tons of shingles from the landfill. “I feel pretty good about that.”
Ellen Ryan is a freelance writer based in Rockville, Md.