If you've ever stepped onto a hot asphalt road surface in the summertime, you'll appreciate how much heat is being generated by the vast surface area of a black asphalt roof. The heat is intensified if you live in an urban or suburban area with many homes or businesses with black roofs in close proximity to each other and to black asphalt roads and parking lots.
This creates a "heat island" effect that causes the mean temperature of the area to rise in relation to surrounding areas, forcing residents to use an inordinate amount of electricity to keep their homes at a bearable temperature.
However, if you have a home with a black roof, you can do your part to help the neighborhood and the planet, while lowering your electric bills and keeping your home more comfortable, by applying a reflective roof coating to your home.
What do you need to apply reflective roof coating?
While aluminum (silver) was originally the predominant color in reflective coatings, you can now find them in various lighter colors. While it is cheaper to buy the coating in five gallon cans, they are heavier to carry up a ladder to the roof than single gallon cans.
Measure the length and width of the roof to find the surface area in square feet (length x width), then check the back of a can for surface area coverage. You may not need a full five gallons, but if you do, lift a five gallon can to see if you can carry it to the roof and around the roof surface as you apply the sealant.
If not, spend a few more bucks for several one gallon cans.
Applicator brush and handle
Roof coatings are thick and best applies with a stiff brush. You can buy an appropriate brush as well as a screw-on handle near the roof coatings at your local home improvement store.
You will need to sweep the roof to remove any loose dirt that will interfere with the adherence of the coating to the roof's surface. If your garden hose is long enough to reach the roof, squirting would be even better for cleaning the roof.
Applying the coating
Reflective roof coating is very sticky, and will adhere to your clothes and skin just as well as it sticks to your roof, so wearing old shoes and clothing, as well as work gloves, is advisable. Remember to start at a point on the roof that is farthest from your access point, which is likely a ladder, so you won't need to walk on the applied coating to get off the roof.
It is best to apply the coating at a time of day when the sun will be behind you as you work. Reflective coatings are effective because they reflect the sun's rays, and you don't want the sun in front of you as you work. A hat and shades are still advisable, even with the sun at your back.
Even if you work with great care, you may find your clothing,shoes, shades, ladder, and everything else you inadvertently touch tainted with the coating material. It may be a better idea to hire a professional with the money you will save on cooling bills than find yourself and your possessions covered with more reflective.coating than your roof.