Albedo the scientific term used in reference to the amount of light reflected by an object, hence it has become the alternative term for a reflective roof coating. These coatings are applied to a roof surface to reduce the amount of heat generated through solar means. When roofing has a reflective roof coating applied, the surface temperature can be expected to drop by as much as 80 degrees F; as a result, a roof coated can have a very positive impact of the cost of cooling. It is estimated that a roof which has been treated with a reflective coating can pare 25% of the homeowner’s annual energy bill.
Reflective roof coatings have another advantage; they are formulated with UV inhibiting pigment. UV (Ultraviolet) rays are responsible for accelerating the aging of a roof considerably, the reflective coating, by inhibiting these harmful rays can add up to 15 years to the life of the roof. This is more apparent on a flat roof or a roof with a low slope as these roofs tend to hold more heat and absorb UV faster than roofs with a higher pitch. In analyzing the total cost of maintenance for a building; the maintenance of Roofing accounts for about 80% of the total. Any product that extends the life of a roof is most certainly welcome as it results in significant savings over the years.
A reflective roof coating is akin to having mirrors on your roof; the coating reflects the radiant energy from the sun back into the atmosphere. Manufacturers have developed a system to classify the reflective index of various materials; the best is bright white paint which has a solar reflectance of more than 85%.
There are various materials used a reflective roof coatings; they include elastomeric, polyurethane and acrylic paints; rubber, plastic or PVC sheets and clay tiles or concrete. Paints can be applied by using a roller and brush and can be done by the homeowner, PVC and other sheet material must be professionally applied as they require a heat source or caulking. For those who wish the best results at the lowest cost, titanium dioxide paint or sheets of aluminum are the best. Both are easy to apply, inexpensive to buy and once applied, require little in the way of maintenance.
The CRRC (Cool Roof Rating Council), in co-operation with the government provide an Energy Star rating to roofing products that pass the tests and are intended as reflective roof coating. As time goes by, the material tends to degrade due to a build-up of dust, dirt and debris. To maintain the effectiveness of reflective Roofing, it must be washed periodically or a reapplication may be needed.
