What’s Worse For the Environment…Your Home’s Roof or Your Car? (Earth Day Pop Quiz)
- Metal Roofing Alliance
- Mar 25
- 5 min read
Updated: 1 day ago
Key Points:
When re-roofing your home, there are plenty of ways you can lessen the impact on the environment.
Metal roofs are a sustainable option when re-roofing your home as a recyclable, energy efficient and longer lasting choice, requiring less maintenance and toxic cleaning methods
Leading roofing experts share their tips for how to choose a more sustainable roof for your home
The roof you choose for your home has real consequences for the environment.
That’s the message this Earth Day, which also happens to coincide with spring and the start of re-roofing season.
And the facts about the most common type of roofing found on the majority of U.S. and Canada homes are sobering: A recent Yale study has found that asphalt products, including roofs and roads, can create urban air pollution that is comparable to motor vehicle emissions.
That’s just part of the problem. It is estimated that more than 13 million tons of asphalt shingles get dumped in landfills each year. Even “innovative” new manufacturing attempts to solve the asphalt shingle roofing recycling problem are estimated to only contain about 15 percent recycled materials. The problem is even worse in regions prone to hail, hurricane, and climate related disasters due to asphalt failing under such extreme conditions such as in Florida where they need to be replaced much more frequently.
Metal vs. asphalt: What’s the environmental difference?
Metal roofing has long been the more sustainable option for roofing, thanks to its ability to be recycled. It is one of the only materials in the world that can be recycled again and again, without compromising its qualities. At the end of its very long life, a metal roof is 100 percent recyclable.
Compare this to asphalt roofing, where estimates indicate that under 10 percent of the total waste created is reused for things like paving roads. Worse, only 31 states currently allow for this, and percentages vary greatly, with many falling well under that 10 percent mark according to a 2017 U.S. Department of Transportation report https://www.fhwa.dot.gov/pavement/recycling/pubs/hif18009.pdf
Beyond recycling, MRA executive director Renee Ramey points out that metal roofing lessens environmental impacts in plenty of other ways. They can last 50-plus years, reducing the need to replace or repair your roof as often and they perform much more reliably, especially in regions that experience extreme weather, storms and wildfire threats. Depending on the condition of your old roof, some metal roofs can be installed right over the top, reducing the waste (and cost) caused by tear off and adding to the insulating properties of your home.
Speaking of energy savings, metal roofs can make a real difference in lowering your ongoing energy costs while increasing the comfort of your home. Considered “Cool Roofs,” many metal roofs are ENERGY STAR-qualified based on total solar reflectance and thermal emittance properties, a term that describes how much of a material’s absorbed energy is released and emitted back into the atmosphere (versus causing indoor temperatures to rise). The Environmental Protection Agency estimates a qualified Cool Roof can lower roof temperatures by as much as 100 degrees F.
Metal roofs also reduce the need for harsh, environmentally damaging maintenance and cleaning techniques. In fact, to keep your metal roof looking as good as new, all that is required is a gentle squirt of water and mild detergent every so often. By contrast, organic material such as leaves and pine needles tend to stick to asphalt roofs which can lead to moss and algae, requiring expensive, environmentally harmful professional treatment annually.
How to choose a sustainable roof for your home
When choosing a metal roof, you can do your part in completing the loop by asking prospective metal roofing installers how much recycled content is used in the manufacturing of products you’re considering, to help identify the most sustainable option possible. The minimum amount of recycled content metal roofs contain is 25 percent, and most have percentages that are substantially higher. When recycling a metal roof, homeowners should look for local metal recycling resources in their area or ask their installer if they provide such a service.
Also, ask about coatings when choosing your new metal roof. High quality metal roof paint and stone coated coatings make a huge difference when it comes to protecting your home and lowering your energy costs. While even basic, unpainted metal roofs will reflect more solar radiation than asphalt roofs, by choosing the proper colors and coatings, low-glare metal roofs reflect most non-visible, infrared and UV rays—the kind that produce heat and are the most damaging.
Make your home’s roof work with the environment, not against
Interested in taking your home’s environmental performance up a notch? Consider the many different functions your roof can perform to lessen environmental impacts and increase home efficiency.
For example, metal roofs are an ideal platform for rooftop solar systems, since the panels can attach via clips and fasteners easily (no penetrations to the roof decking required, which prevents possible future leaks and damage) and they last far longer than solar panels themselves. That means, you won’t need to replace the roof before the panels.
Metal roofs also are a great solution for rainwater collection systems. Compared to other materials, metal roofs have much lower concentrations of dissolved organic carbon and other bacteria (note rainwater harvested from any type of roof, including metal, should always be filtered, and decontaminated before use). By contrast, some experts warn that older shingled (asphalt) roofs made before 1980 may contain asbestos which is hazardous if disturbed. Even if your shingles are new, not all varieties are safe for water collection and can leach contaminants and large chunks of grit.
Want to know more? Geeking out on how metal roof recycling works
Step by step, here’s how the metal roofing recycling process works. Once the metal is received, recyclers first sort it based on its quality and material type. The metal is compacted to save room and then shredded or broken down into smaller pieces to be melted in a way that requires less energy.
Steel is then typically formed into blocks, while aluminum is rolled into sheets. Copper is also routinely recycled, with the highest scrap value of any building metal. Scrap is then melted in a large furnace which does require energy, but much less than what it takes to make raw materials*. Metals are then purified and transported to different mills to be remade into new products, including metal roofing.
“It’s the ultimate goal of recycling in action,” said Ramey. “Unlike asphalt or other roofing materials, the need for raw materials and energy for manufacturing is greatly reduced, and reusing metal again and again will not impact its performance qualities, now or in the future.”
*According to the Metal Construction Association, recycling decreases the amount of energy required to produce metal products like metal roofing. For example, producing aluminum from recycled material requires only 5 percent of the energy required to produce aluminum from originally sourced bauxite ore and every ton of recycled aluminum saves four tons of bauxite. Using recycled aluminum instead of mining for new materials also reduces air pollution by an estimated 95 percent and water pollution by an estimated 97 percent. Source: Technical Brief: Recycled Content of Metal Roofing and Siding Panels, Metal Construction Association
