Asphalt shingles: What’s wrong with them?

Asphalt shingles: the unsustainable roofing choice. Studies show that climate change will cause stronger and more frequent hail storms and other weather patterns. With hail the size of golf balls, asphalt shingles don’t stand a chance. The numbers of homes in Bozeman, MT that have been re-roofed since the devastating Spring 2010 hail storm is a message to local builders and homeowners that this product is not a cost-effective roofing material.
Asphalt shingles are not resistant to hail and dramatic temperature changes. They only last an average of 15 years. When old, nonfunctional shingles are removed from a home, they usually are not recycled and end up in landfill. “The amount of asphalt shingles that goes into landfills on an annual basis is approximately 7-10 million tons.” If asphalt shingles are recycled, the recycling product often is not safe nor environmentally-friendly For example, one recycling company sold tons of mulched asphalt shingles for landscaping. “In 2004, the DEQ determined that the mulch contains toxins such as arsenic and polyaromatic hydrocarbons in concentrations higher than those considered safe for soils at residential and commercial settings. The agency directed Darold Smith, owner of the Springfield manufacturing site, to stop selling the mulch to homeowners and nonindustrial firms”

Many builders that advertise their company as “Green” frequently install asphalt shingles. I find this to be highly contradictory. The health aspect of asphalt and fiberglass shingles is also questionable. People who install shingles are at serious health risks. “Fiberglass shingles have a base layer of glass fiber reinforcing mat. The mat is made from wet, random-laid fiberglass bonded with urea-formaldehyde resin. Fiberglass reinforcement was devised as the replacement for asbestos paper reinforcement of roofing shingles.” By tearing, cutting, breathing, and handling shingles, workers are exposed to carcinogens. Asphalt itself is a dirty industry based on petroleum and its associated distillates. The off-gassing of such additives occurs when heated. According to the warranty on the shingle packages, the shingles must not be laid in the cold, meaning that they should be installed when its warm. That’s when the shingle heats up and starts to off-gas. Many shingles are now made with a mild algicide and/or fungicide. Usually this is a copper compound, but may be a more complex chemical.

“WARNING: The National Institute for Occupational Safety and Health (NIOSH) has concluded that fumes of heated asphalt are a potential occupational carcinogen. Do not burn asphalt roofing products.”

How long do asphalt shingles really last?  The shingle companies claim that asphalt shingles will last 25 years, however, they also explain that this warranty is under ideal application, location, temperature, and installation practice. There are whole websites dedicated to helping people who have been scammed by Roofing shingle companies like this one.  Studies show that shingles do not last as long as the roofing manufacturers claim. “According to the insurance industry, an asphalt roof that is over 17 years old has zero value in the event that there is a loss. The insurance industry has also stated that there is no reliable testing that has been done on these products. ” Asphalt shingles usually last longer in cooler climates than warmer ones. Thermal shock, when the ambient temperature changes dramatically within a very short period of time, is damaging to the shingles.  One additional thing to think about is how climate change is effecting temperature swing radicalization.  Asphalt shingles don’t perform well when temperatures increase and decrease radically within short time spans which is where we are heading.

Frequently re-roofing your home ultimately causes your roof to leak. When nailing down asphalt shingles, the roof boards or under sheathing are perforated with a nail nail every 8 -12 inches. Rather than protecting your roofs, installs asphalt shingles just adds more holes. When your shingles fail and the roof is leaking, it is very difficult to patch the roof. Usually, a leaky, overly perforated roof must undergo a complete re-roof, which is an expensive project.  This is an example of life-cycle cost, or pay less now and pay more later, and again, repeat.
One other thing to keep in mind if you live in snow country, asphalt shingles really should Not be used on pitches less than 5/12!  Yes the asphalt shingle companies say that they can be used down to a 3/12 pitch but I can assure you the snow build up and freeze thaw cycles will eventually cause problems  called ice damming.  Steeper roof pitches will drain better and snow will not collect  as deeply this is the key to keeping winters destructiveness at bay.  And one last thing, every shingle, and there are a lot of them on the average sized homes roof, is a possible leak, it is very possible due to extreme repetition of laying them that the roofer will make a mistake.  Saving money today on asphalt shingles means spending later on a re-roof because of  water damage, or asphalt shingle failure.
So, what is good roofing? Read my follow-up post that discusses Metal Roofs: the sustainable alternative.


  • February 15, 2011

    Can you suggest a roofing material that you like? For a Boston climate — cold and snowy in winter, hot in summer? I’d appreciate a post about that. All I see here is a rant against asphalt…

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