Harnessing the Cool Benefits of Cool Roofs. Cool roofs keep homes cool by reflecting most of the incident heat from the sun.
This reflection promotes energy efficiency because reducing the amount of heat absorbed by the roof and transferred to the home’s interior reduces the amount of energy consumed by HVAC systems. And that’s just half of the good news. Perhaps the best thing about cool roofs is that most roof surfaces can be made reflective without a complete roof overhaul.
Making Existing Roofs Cool
A Quick Note
Modified bitumen sheet membranes can only be pre-coated with cool roof coating during the manufacturing process. Spray polyurethane foam roofs, on the other hand, are already reflective to begin with so they don’t really need further treatment.
As for existing asphalt shingles, you may have them cool-coated, but you’ll be doing so at your own risk as it is not recommended by most manufacturers.
If your roof is due for replacement, there is no reason for you not to get a cool roof as it will cost roughly the same as its conventional counterpart.
As a takeaway, keep in mind that improving your roof’s energy performance depends on more than just what’s on the surface (see Part One). For best results, consult a trusted contractor about taking a comprehensive approach to roof energy efficiency.