Shakes and shingles are the most popular types of roofing materials in North-America. 2/3 of all North-American homes have asphalt shingles. But even the best manufactured and light-colored, asphalt shingles and shakes are among the least energy-efficient roof products. They collect to much heat in the summer, and are responsible for a large part of our cooling bills.
Asphalt shingles and shakes do not provide any significant reduction in heating costs during the heating season and may cost you many hundreds of dollars in air conditioning, in the summer.Clay tiles
Contrary to asphalt shingles and wooden shakes, light-colored clay tiles are a good choice to keep your roof cool.
They are among the best rated products for “cool roofs”: their "reflectance" is about 70% on a 0-100% scale, which is comparable to the new white anodized aluminum and white galvanized steel roofs.
Though they come in a wide range of colors, the lighter ones are the best to protect the roof from solar heat.
Other advantages of clay tiles:
- their curved shape, which allows excellent ventilation;
- their ability to be recycled.
- their long durability: there are porous and and low quality tiles that do not long last; but good quality ceramic tiles can last many decades without needing any special maintenance, withstanding very harsh winds, snow, hail and other very adverse weather conditions.
New asphalt shingles
Asphalt shingles can now be engineered to provide a better reflectivity. Manufacturers are using a highly reflective granule technology to reflect the sun's rays and to help keep roofs cooler.
These “cool shingles” meet the solar “reflectance” required by the North American Energy Star program (25%) and the Cool Roof Rating Council (CRCC).
But though they are a better option than the traditional asphalt shingles (with a typical reflectivity of 5%), they still fall short from the best. White clay tile and some metal roofing products, and several roof coatings and membranes provide three times more reflectivity…
High rated Asphalt shingles
If your cooling costs are not significant and you prefer asphalt shingles, choose products qualified by the Energy Star program and the Cool Roof Rating Council (CRRC). They meet the California Title 24 requirements or the ASTM D 225 and the American Society for Testing and Materials (ASTM); fiberglass shingles should meet the ASTM D 3462 standards.
Energy Star manufacturers list:
If interested in ceramic tiles, consider products that meet the Energy Star program standards. They are more energy-efficient and will last longer.