Recycling Building Materials Saves Money and Helps the Environment
Bird's eye view
Many materials can be recycled instead of pitched
Construction generates a huge amount of waste. Most of it is typically thrown into a Dumpster and hauled away. But tipping fees are getting steeper, and landfills already are overburdened. Recycling waste often makes more sense, not only because it can be cheaper but also because it's less of an environmental burden...
Some materials are easier to recycle than others
Building sites produce all kinds of waste: gypsum drywall, wood, asphalt shingles, plastic, cardboard and metal. Recycling markets are well established for some materials--metal and some plastics, for example--but not for others. Some materials have inherent value, while others aren't worth much, and both state regulations and recycling opportunities are mixed.
To recycle, you need a plan
Organize the job site so materials can be sorted as construction waste is generated. When debris is all thrown in one pile, recycling gets much more difficult, so designate specific areas for wood, metal, cardboard and other materials. Make sure everyone working on the site, including all subcontractors, understands the plan and knows where different types of waste should go.
Investigate local recycling options
Comparing the cost of recycling materials to standard tipping fees can be a powerful incentive. Finding markets for recycled construction debris may take some work, at least the first time around. Opportunities vary from state to state, as do tipping fees at local and regional landfills. Although some states offer relatively few opportunities to recycle certain types of debris, others have much more active programs. Take advantage of whatever referral services state environmental offices and industry trade groups have to offer. There are a number of on-line data bases that can help.
Earn green certification points
Houses that generate less waste earn points under green certification programs. By cutting construction waste to a half-pound per square foot, for example, builders can earn 3 points in the LEED for HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify.
program. The NAHB Model Green home building guidelinesThese guidelines were finalized in 2004/2005 and are "...a tool kit for home builder associations to creae new programs and to help those programs expand and flourish." Builders can sign up on the NAHB Green website to use their web-based scoring tool to assess their project(s) according to the Guidelines. As soon as the ANSI National Green Building Standard is available, builders will be able to score their projects according to the Guidelines and/or the standard.
also award points for developing a waste management planPlan that addresses the collection and disposal of waste generated during construction or renovation, usually including the collection and storage of recyclable materials. and for recycling construction waste.
Reduce waste, conserve resources
Construction in the U.S. produces millions of tons of waste every year. Disposing of it conventionally, which means trucking it to landfills or incinerators, is costly to builders and, ultimately, costly to the environment. Recycling construction debris is one way of lowering building costs, extending the life of landfills, and funneling some raw materials back into the production stream.
Recycling also has enormous potential for saving energy. It takes much less energy to make new products out of recycled material than it does making them from scratch. Recycling one ton of aluminum, for example, saves the energy equivalent of 36 barrels of oil. Nationally, about 30% of all municipal solid waste is recycled, saving roughly 1.5 quads of energy per year, or 1.5% of the nation's total energy consumption.
Although recycling has become a core principle of green building, in practice it poses challenges even for builders who are interested. For a variety of reasons, recycling channels for some types of clean scrap can be hard to find. For demolition debris, it gets even tougher. As a result, lots of construction debris is still taken to landfills or incinerators.
Types of debris
Major categories of construction debris include cardboard and paper, PVC and other plastics, asphalt roofing shingles, gypsum drywall, metal, and wood. Some of it is fairly easy to recycle. There's a long recycling history for cardboard, metal and some plastics, for example. Other materials are more difficult to recycle because the material has limited value, or because there aren't many processors capable of handling it.
Opportunities vary by state
Some states have very active recycling programs for construction debris while others do not. In addition, regulations on the disposal of construction waste vary from state to state. Massachusetts, for example, bans the disposal of gypsum drywall scraps in state landfills while other states do not regard the material as hazardous and don't regulate its disposal. To find out more, check the state-by-state list of contacts maintained by the Construction Materials Recycling Association.
Recycling can save money
Landfilling waste can get expensive. Tipping fees vary by state, but they can top $100 per ton. Where opportunities for recycling exist, they can be much lower. In a 2003 case study in Massachusetts, clean drywall scrap from a public school project was trucked to a processor in neighboring New Hampshire for a cost savings of roughly half. Overall, the contractor on that job lowered disposal costs by about 75% by recycling construction debris.
Taking construction debris to a recycler isn't free, but it often costs less than conventional disposal.
MORE ABOUT RECYCLING
Gypsum drywall has many potential uses
Clean drywall scraps make up one-quarter or more of home construction waste, according to the Michigan Department of Environmental Quality. Nationally, an estimated 2.7 million tons of clean drywall scrap are produced every year in the form of offcuts during installation.
Drywall is more than 90% calcium sulfate dihydrate, a natural mineral. The rest is mostly paper. When ground up, it can be used in a variety of ways--as a soil amendment, mixed with animal waste to reduce odor, used in the production of cement, combined with wood shavings for animal bedding, and used in the production of new drywall.
These end uses are more attractive than dumping drywall in a landfill, not only because it doesn't make sense to throw away a material that can be re-used but because finely ground drywall can produce hydrogen sulfide, a noxious gas that can be toxic at high concentrations.
One potential use is to send clean scrap back to manufacturers so it can be used to make new drywall. This has been successful in the past, but a slumping housing market has reduced the demand for new drywall, and that may affect the willingness of manufacturers to accept scrap: They may not need it.
In addition, coal-fired power plants produce a synthetic gypsum from air scrubbers. The president of a Pennsylvania-based drywall processor says 18 million tons of the synthetic gypsum was produced in 2009, but only half of it found its way into new or repurposed products. That also contributed to a glut.
Builders looking for an out might consider buying equipment allowing them to grind up clean scrap on site and spread it over the ground or mix it with soil used to plant lawns and gardens. A Texas company makes two models of a trailer-mounted machine called the Gyp Monster. It's probably not worth the cost to someone who builds a couple of houses a year, but it might make sense to a production builder generating lots of waste.
In some areas, it may be possible to bring in bigger equipment to grind up construction debris, such as wood, drywall and concrete. GBAGreenBuildingAdvisor.com technical director Peter Yost visited one such company, Packer Industries, in Mableton, GA, for a demonstration.
There are established processors in some parts of the country, but not everywhere. In the end, only a small percentage of clean drywall scrap actually gets recycled. And the old drywall produced during remodels and demolition? It could be contaminated with lead paint, asbestosMineral fiber once commonly used in many building materials, including insulation, fireproof siding, and resilient flooring. Inhalation of invisible asbestos fibers can lead to chest and abdominal cancers as well as scarring of the lungs. The use of asbestos in some products has been banned by the EPA and the U.S. Consumer Products Safety Commission; manufacturers also have adopted voluntary limitations on its use. When found in older buildings (most commonly in floor tiles, pipe and furnace insulation, or asbestos shingles), the product's friability is a major determinant in how it must be handled during renovations. More information: http://www.epa.gov/iaq/asbestos.html or some other toxic material, and because of that it's typically not recycled at all.
PVC has very low recycling rates
Polyvinyl chloride is a widely used thermoplastic used to make everything from siding to pipes and floor tile. In North America alone, more than 19 billion pounds of PVC are produced annually, three-quarters of which winds up in construction materials.
In theory, PVC can be melted down and used to make new products. But the reality is that very little of the PVC used in the construction industry is ever recycled. The Vinyl Institute, an industry trade group, says more than 1 billion pounds of vinyl were recycled in North America in 1977, but most of that was in the form of post-industrial scrap.
Post-consumer scrap is another story. More than 2 billion pounds of post-consumer waste (PVC products that are worn out or removed in demolition) are landfilled every year. One reason for the low recycling rate is that additives used to make specific building products make it harder for manufacturers to re-use the material in new products. To make a window frame, for example, a manufacturer may need different additives than if the product were pipe. Virgin material is more predictable and easier to use. Manufacturers also say that PVC's very long service life makes it difficult to find a reliable supply of scrap.
Recycling programs aimed specifically at PVC seem in very short supply. But there are some bright spots. Manville, CertainTeed, Charlotte Pipe and Foundry Co., Allied Companies and LSI Wallcovering are among companies that convert post-consumer PVC into new products, including floor tile, siding, non-slip flooring, pipe, and wall coverings. In the case of CertainTeed, CedarBoards vinyl siding contains 60% recycled materials, including job site scrap and other post-consumer sources.
One source of information about recycling is a Vinyl Recycling Directory maintained by the Vinyl Institute, an industry trade group. You can search by company name or by state (but don't be surprised if your search comes up empty).
Asphalt roofing shingles are worth money
Asphalt shingle waste, most of it from tear-offs, has lots of potential uses:
- Cold patch for repairing potholes.
- Mixed with gravel or ground concrete, as a road base for driveways or a cover for unpaved roads to reduce dust and extend road life.
- To make new shingles.
- To make hot-mix asphalt for road construction.
The high petroleum content in shingles gives them an inherent value that other types of construction waste don't seem to have. The Construction Materials Recycling Association reports tremendous growth in shingle recycling in the last decade, but it's still a hit-or-miss situation depending on which state you happen to live in. For more, check the the association's web site.
Hot-mix asphalt improves with the addition of some ground shingles, with less cracking and increased stiffness,. But not all states have written specifications allowing its use in public road construction.
One concern is the possible contamination of shingles with asbestos. This carcinogen is no longer used in the manufacture or roofing materials, but it's not uncommon for older houses to have two and sometimes even three layers of shingles on the roof and the older the shingle the greater the possibility of asbestos. Testing by a processor in Massachusetts, however, has turned up an extremely low incidence of asbestos in shingles.
Shingle processors aren't available everywhere. But they can offer lower disposal fees than landfills. One Massachusetts processor, for example, charges from $10 to $40 less per ton than landfills around the state.
- USA Gypsum
- Rob Wotzak
- Jeff Medanich
- David West