SHSC TIPS: REPLACING ROOFTOPS - HOW TO GET THE BEST ENERGY SAVINGS
- Replacing roofs is an excellent opportunity to improve energy efficiency
- Using light coloured shingles, surface coating and gravel can further add to your energy savings
- ENERGY STAR® cool or reflective roof products reduce the amount of heat transferred into a home
- Strategically planning and timing your projects together will help you achieve maximum savings
- Roof replacement time is the best time to consider a renewable energy system
Replacing a roof due to damage and/or age presents an excellent opportunity to improve energy efficiency, comfort levels for tenants, reduce operating costs and C02 emissions which cause Global Warming.
In the case of a sloped roof aim for a minimum of R40 or, preferably, R50. Insulation will not meet its maximum effect in an attic setting unless the attic is properly sealed and a continuous vapour barrier has been installed.
For a flat roof aim for a minimum of R30. This may not always be achievable because of other structural issues such as rooftop mechanical rooms, roof access points and ridge height, but it is important to instruct your contractor to achieve as high a level as possible.
Further savings can be achieved by using light coloured shingles, surface coatings or gravel. These materials reflect heat during summer months rather then absorbing it as dark coloured materials do. An energy efficient roof should reflect a high percentage of solar energy and radiate away energy (heat) after it is absorbed. ENERGY STAR® cool or reflective roof products reflect more of the sun’s rays, lowering a roof surface temperature by up to 100 degrees, and reducing the amount of heat transferred into a home. The ENERGY STAR® program presently considers reflectance only, not emittance. A Roof’s emissivity relates to how quickly it releases heat it has absorbed. Because of this property cooling costs are reduced. This measure also helps to reduce "heat island effect", a contributor to global warming, particularly in dense urban areas.
As with every energy efficient retrofit measure, maximum results are achieved by combining efforts. The savings gained by a well insulated roof are leveraged by caulking and weatherstripping the building envelope which, in turn, maximizes the efficiency of the HVAC system or, in the case where a system is being replaced, can result in a smaller, less expensive replacement.
Roof replacement time is also the best time to consider a renewable energy system. Because Solar systems have a life span of at least 20 years and, in the case of Solar PV, Solar Thermal and Solar Air roofing, a considerable portion of the cost is installation on the roof, a new roof gives a much greater degree of certainty that these systems will not need to be removed for re-roofing.
Combining all of these measures will result in a healthier, more comfortable building, reduced operating costs, a revenue stream (in the case of Solar PV) from the Feed In Tariff (FIT) and a greener community.
WANT MORE INFORMATION?
Call SHSC Customer Care toll-free at 1-877-733-7472 (1-877-733-SHSC)
or e-mail at customercare@shscorp.ca