Greenest Roofing EcoLiving

Greenest Roofing EcoLiving

Greenest Roofing

Your choice of roof influences not only the look but also the durability and environmental footprint of your house. Plus, your homes orientation (north vs. south) and the roofs pitch (the sun hits a flat roof more than a steep one) will also affect your heating and cooling needs. Dark roofs may look sharp but they can raise the temperature of your home in summer; lighter colours reflect the heat away and can reduce your need for fans and air conditioning.

Asphalt shingles

Easy to install, relatively affordable and good-looking, asphalt shingles are the most popular roofing option in Canada. The two main versionstraditional organic and the newer fibreglass shingleslook the same on your roof, though fibreglass shows a greater resistance to heat and a better fire rating, and is more popular in mild to moderate climates. (Incidentally, in the roofing world, organic doesnt mean chemical-free, but refers to the paper-based substrate that forms the body of organic shingles.) The most expensive of both types of shingles carry warranties of up to 40 years. Asphalt is a non-renewable resource sometimes derived from crude petroleum. Choose light shingle colours to prolong your roofs lifespan; darker colours absorb more heat and break down faster. Research by the Lawrence Berkeley National Laboratory also shows dark roofs contribute significantly to the urban heat island effect, a worldwide phenomenon in which cities regularly reach much higher temperatures than the surrounding countryside because of the extra solar energy they absorb.

Metal Roofing

Although energy-intensive to manufacture, metal roofing is one of the greenest options because it lasts for decades, is easily recycled and radiates heat out to the environment rather than to the house. Galvanized steel and copper are traditional choices, but the most common and economical are made with a blend of zinc, aluminum and steel. Most versions typically come as factory-painted panels, with lighter colours reducing summertime heat build-up. Available as ribbed, factory-finished sheets or textured products that mimic wood shingles or tiles, metal roofs cost more initially than other options. Weathering of the factory finish is often the limiting factor in how long a painted metal roof remains acceptable-looking, so ask about finish warranties. Unfinished metal also contributes to the urban heat island effect. Metal is one of the easier choices to install yourself, and it goes on fast.

Wood Shingles & Shakes

Attractive and traditional, wood shingles are sawn from logs and are typically 3/8 to thick at the ends, while shakes are thicker and longer, and have a more irregular visible face thats formed by cleaving the wood. The environmental impact depends on how the wood was harvested, so shop for products with Forest Stewardship Council (FSC) certification. Installed properly for drainage and ventilation, and secured with stainless steel nails or staples, wood can last longer than cheap asphalt, though not as long as other options. Although more challenging to install than asphalt, wood shingles can be applied by do-it-yourselfers. Not all roofing contractors will tackle wood installation.

Synthetic Shingles

Often made from post-consumer recycled plastics and fibres, synthetics like those made by Euroshield and Enviroshake are convincing substitutes for slate tiles and cedar shingles and shakes. Some synthetics offer warranties up to 50 years, along with an excellent appearance, making them one of the most environmentally friendly roofing options. Priced comparably to cedar shingles, each brand of synthetic shingles has a unique design, and can be installed by local roofing contractors or handy homeowners. Theyre decay-proof and strong enough to resist physical damage. Certain brands are made to look weathered, like wood shingles. Choose light colours to minimize added heat in summer.

Natural Slate Shingles

Extreme durability makes slate roofs green: they routinely last 75 to 150 years (especially if installed with rustproof stainless steel nails). Slate is an expensive choice that requires specialized skills for installation and repair, but long-term reliability gives it a low annual cost. The only drawbacks are that slate requires mining, which has an impact on the landscape, and most slate roofing comes from China. If youre going to build a slate roof, which is rare in Canada, pick salvaged or reclaimed slate, which The Sierra Club considers the most sustainable choices.

Clay or Concrete Tiles

Greenest Roofing EcoLiving

A long working life and classic good looks are pluses for clay and concrete tiles, though not all roof structures are strong enough to support their weight. Energy-intensive manufacturing and transportation are the biggest environmental drawbacks, but clay and concrete tiles are rated one of the top environmental choices by the British Building Research Establishment. Clay and concrete require installation by specialized tradespeople. Look for a lightweight product that contains recycled content and can accommodate a solar roof tile, such as one made by UniCrete in Calgary.

The most sustainable roofs are literally and figuratively green when they feature plants growing over a waterproof membrane. These green, or living, roofs lower cooling costs by 50 to 90 per cent; minimize rainwater run-off; remove carbon from the atmosphere; improve household soundproofing; and help reduce the urban heat island effect. Despite their high cost (prices start at $18 to $25/sq. ft.), the total area covered by green roofs increased in North America from one million sq. ft. in 2004 to 14.3 million sq. ft. in 2010. Much of this real estate sits atop institutional and commercial buildings, but nearly 1,244 individual green roofs have been registered at greenroofs.com .

Solar Shingles

A growing number of tiles, roofing membranes, shingles and metal roofing options can convert sunlight into electricity. But unlike standard rooftop solar panels. these building-integrated photovoltaics (BIPVs) improve aesthetics associated with solar panels while maximizing the roof area devoted to generating clean electricity. At this stage, BIPV roofing is far from mainstream; you wont find the materials at conventional building outlets yet, and feed-in tariff programs are still required to make BIPV roofing cost-effective. Dow Chemical is poised to launch a photovoltaic shingle that works in conjunction with regular asphalt shingles to deliver lower-cost electricity than conventional solar panels.

Steve Maxwell is a syndicated home improvement and woodworking columnist, and has shingled more than a few steep roofs himself. Get more roofing advice from Canadas Handiest Man at his website .

Materials reviewed by Brandy Burdeniuk, a LEED Accredited Professional, sustainable building materials specialist and co-founder of EcoAmmo. a consulting firm that offers research and education about green design.


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