All About Energy-Efficiency
We have come a long way from the days when homes and other buildings were covered by the kind of material that was nearest to them. Hand-split slate was commonly used as roofing material in areas where there was plenty of slate to quarry. In some places, stones were used to cover buildings due to their availability, but were soon replaced by thatch, and eventually clay tiles, as soon as resources were depleted.It simply became too difficult, not to mention impractical, to transport all the stones using horse-drawn carts for miles.
Nowadays, every town has a roofer that is affiliated with manufacturers thatcan supply many types of roofing materials for any style of home. However, it is not just the materials anymore that people are concerned with, but how energy efficient they are. Yes, I am talking about the energybills that don’t seem to go down one bit. Current advancements in technology have allowed roofing manufacturers to develop roofing materials that are more energy-efficient than ever before.
The Dawn of Energy-Efficient Roofs
Roofing today has become more than just “putting a roof over your head.” The main focus of manufacturers is to cater to the demand for an environmentally safe, energy-efficient roof.
The ENERGY STAR label, for example, is the government’s way to help consumers choose products that are certified to be energy-efficient. Roof products that are ENERGY STAR qualified can decrease the overall temperature of a roof’s surface by up to 100°F, and reduce the maximum cooling demand of buildings by as much as 10 to 15 percent.
Among the roofing manufacturers that are known to offer energy-efficient roofing materials are GAF, Firestone, Duro-Last, Carlisle SynTec, and Hydro-Stop. These manufacturers have created products that have passed EPA’s guidelines for the ENERGY STAR program.
Now what makes roofs energy-efficient? There are two terms you need to keep in mind for now: (1) emissivity and (2) reflectivity. Emissivity is the ability of the roofing material to release any heat that it absorbed. Reflectivity, on the other hand, is the capacity of a roofing product to reflect the sunlight and heat away from your home. The higher the solar reflective value of a roof, the bigger your energy savings will be.
This is why reflectivity and emissivity ratings are largely considered in rating systems such as the US Green Building Council’s LEED (Leadership in Energy & Environmental Design) and various local and state building codes. ASHRAE’s (American Society for Heating, Refrigeration, and Air-Conditioning Engineers) Standard for the Design of High Performance Green Buildings have served as a reliable guideline in a national scale in terms of roofing requirements, despite the fact that there is no national code regulating reflectivity values and other factors for energy-efficiency.
Types of Energy-Efficient Roofs
Cool roofs–an umbrella term for roofs that have reflective coating, which may be in the form of paint, tiles, shingles, or a sheet covering that reflects more of the sun’s rays than absorbs them. With cool roofs, you can lower roof temperature by 50°F and use your AC less frequently.
Green roofs – If you have a green thumb and have a flat or shallow-pitched roof, then by all means try having a green roof. Whether it is just shrubs or a more complex garden, having a green roof allows you to putrainwater to good use, not to mention having a living space on your rooftop. More importantly, green roofs provide insulation,reducing the need for heating and cooling.
Partners in Energy Conservation
One of the key ingredients of an energy efficient roof is attic insulation. Heat rises, so proper insulation under the roof goes a long way to keep heat from escaping your home in the winter, and conversely keeping the heat of the summer out. Have you ever been up in the attic during the summer? Then you know how incredibly hot it can get. Most attics have some insulation, but many, especially older homes, are inadequately protected. Have yours inspected and add more to increase your insulations R factor (measure of thermal resistance) for increased energy efficiency and lower energy bills!
There are also radiant barriers or reflective insulation systems that reduce the radiant heat transfer that goes from the underside of your home’s roof to other surfaces in your attic. These are recommended for homes in hot climates as they can reduce cooling costs by as much as 5-10 percent.
Mike Curcio is one of the proprietors of CMS Roofing. His extensive years of experience in the field of roofing and exterior design have enabled him to help customers find what they need in their homes. His writing works on the company’s blog were creating ripples of information in helping a much larger group of readers and customers inside and out of the Carolinas.