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Eco Roofing Options

Wayne Gjerde
Minnesota Pollution Control Agency

Replacing your home’s roof can be expensive and, given the importance of a roof to your home’s health, it is important to review all the options available. If chosen wisely, the material used to roof your home can directly impact your energy savings and provide other environmental benefits.

Asphalt Shingles

Asphalt shingles are the most commonly used material for roofing homes. They are relatively inexpensive and easy to install, but only have a lifespan of approximately 20 years (the shortest lifespan of most roofing options). Every year Minnesotans add approximately 400,000 tons of shingles and related waste to the landfill. Recycling these shingles would save approximately 200,000 to 300,000 cubic yards of landfill space. Tear-off shingles contain at least 20 percent asphalt oil and approximately 32,000 tons per year of virgin liquid asphalt oil (binder) that could be conserved by recycling shingles into hot mix asphalt (HMA)

In Minnesota several facilities reprocess tear-off shingles for new use by hot mix asphalt plants. If you choose to reroof your home with shingles, ask your contractor if he is recycling the old shingles as well as how the new shingles were processed. Use the longest lasting shingles that fit your budget. Ask your contractor to contact the following facilities that can recycle and process: DEM-COM, Ohman Brothers, Shamrock Recycling, Atomic Waste, and SKB. You can also refer online.

Metal Roofing

During the last few years, metal roofing products have emerged. Metal is highly durable, lightweight, fire-resistant and—in most cases—easy for professionals to install. Metal roofing is available in a variety of materials, primarily from aluminum and steel—but other materials such as copper and alloys are also used. These metals bring a combination of strength, flexibility, and longevity.

Metal roofing can be formed into shapes that imitate Spanish tile, wood shakes, or slate, and they are given a multilayer factory finish that includes granulated-stone topcoats to complete the realistic effect. Most metal roofing products carry long-term warranties.

The ecological benefits of metal roofing include : (1) sustainability, as metal roofing’s durability can virtually eliminate the need to use future raw materials to produce roofing, (2) recycling, as most metal roofing contains some recycled content while steel, aluminum, and copper are 100 percent recyclable, (3) safety, as metal roofing and finishes are nontoxic materials and noncombustible, and (4) energy efficiency, as the reflectivity is higher than of shingles and metal has a low thermal massive (does not retain heat as long).

The initial cost of a premium metal roof is higher than most other roofing materials. Homeowners need to compute the lifecycle cost to see if paying more for a metal roof initially will prove to be a better long-term investment than some other form of roofing.

Solar Shingles

There are two types of solar shingle systems available: the off-grid system is self-contained while the on-grid system is attached to the public utility. The working mechanism behind the shingle solar system is the same as traditional solar panel arrays—it collects sunlight and converts it into electricity through photovoltaic cells. The only difference is that the shingle systems use materials that are much smaller in size. However with the newest solar technology, they are still able to produce just the same amount of solar energy. They are more efficient and absorb more light than other solar materials and yet are durable enough to be utilized in roofing materials.

These new solar shingle systems look like traditional asphalt shingles and can be replaced as easily as asphalt shingles. Almost all shingle systems in the market will last for at least 20 years, and they are able to sustain even harsh weather like storms and high winds.

Because of the immense amount of heat that they absorb, these solar shingles usually require an under-decking of ventilated plywood. When they are laid on the roof like asphalt shingles, they overlap and provide the same protection and weather shedding effect. The wiring from the shingles runs through the roof deck to an area where they can be connected to the solar inverter.

While installing solar shingles can be expensive, the monthly costs of energy production can be greatly reduced, making the cost of energy less expensive over time. Right now, the solar roof shingles are still fairly new in the market, and it is in your best interest to purchase from reputable manufacturers that provide professional installation. Check with the manufacturer for a certified contractor.

Rubber Roofing Shingles

Rubber shingles are a great alternative to standard roofing materials, especially on historical homes. For homeowners that want to preserve the integrity of the look of their home, rubber shingles can easily mimic the more traditional shingle types (such as cedar shake, tile, and slate) at a fraction of both the cost and the overall weight. Rubber shingles are made of recycled materials such as rubber tires and plastic bags. The shingles also frequently incorporate recycled parts of other materials. For instance, shingles made to look like cedar shakes will often include saw dust from saw mills while slate-like shingles will include actual slate dust from recycled slate shingles. They are also excellent for withstanding pests, are recyclable and fire resistant, and resistant to breaking or cracking,. They provide waterproofing options and great insulation for the home.

Rubber roof shingles have been on the market only since 1993, which means that many roofers are unfamiliar with them. Because of this, they often charge more to install them, sometimes more than twice as much as traditional wood or slate shingles. Also, due to their long life expectancy—up to 100 years according to one manufacturer—make sure that you use top quality peripheral materials such as bituminous membrane along all edges and heavy duty aluminum or copper for the flashing. Regardless, you often get a distinct tire smell when they are first installed due to their manufacture from recycled tires. This fades with time and should not be noticeable after the first couple of days.

Energy Savings

As part of the new American Recovery and Reinvestment Act of 2009, homeowners who choose energy-efficient roofing systems may qualify for a federal tax credit of up to $1,500 if the roof is installed between January 1, 2009 and December 31, 2010. Please check with your tax preparer for advice on whether your roofing choice qualifies for this tax credit.

Eco Roofing

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