| JUNE 2008
Sensible metal roofing gains homeowner interest
The Environmental Protection Agency reported that $40
billion is spent annually in the United States to cool buildings. This
accounts for one-sixth of all electricity generated in a year. These
staggering statistics, coupled with the rising cost of heating and cooling
homes, have homeowners looking for ways to save the earth and save money
on energy costs.
The metal roofing industry’s products are environmentally friendly as
most metal roofs contain more than 25 percent recycled content. This
level of recycled content allows metal roofing to be included on listings
of ‘green’ and recycled content products. In addition, metal roofing
is 100 percent recyclable. Traditional roofing products, such as asphalt
(if not recycled), contribute 13 billion pounds of waste to United States
landfills annually. Many metal roofs can be installed over an existing
roof, without tear-off and disposal.
A cool roof is often described as one that has a high solar reflectance
and a high thermal emittance. The emittance of a material refers to its
ability to release absorbed heat. A roof is ‘cool’ if its surface temperature
is lower, and as a result, the cooling load in the building is reduced.
Solar reflectance is the most important characteristic of a roof product
in terms of yielding the highest energy savings during warmer months.
The higher the solar reflective value, the more efficient the product
is in reflecting sunlight and heat away from the building and reducing
roof temperature.
A study conducted by Oak Ridge National Laboratory found that the installation
of highly reflective metal roofing coatings can save homeowners up to
forty percent in summer cooling costs. Special pigments for metal roofing
coatings have been developed and tested that increase the solar reflectivity
of the metal roof. The vent technology creates an insulation barrier
that aids heating during the winter months.
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