Painting the Roof?
Yes. Painting your roof can save you money on cooling. This concept is as basic as it gets. Black absorbs heat, white reflects heat. Paint your roof a reflective color and save money.
The paint used on roofs is elastomeric, meaning it will expand and contract with the material it is adhered to. These roofs have become mandatory in Chicago for all new construction projects. This method will save you 15-30 percent on your cooling bills and it will cost less than $300 for a 1,000 square foot roof area if you do it yourself. It also will seal any seams that may have split or holes not visible without close inspection.
Generally 2 coats are needed to have the proper thickness. The paint can be applied with a roller or spray gun. The temperature to apply elastomeric coatings should NOT be below 40 degrees as the paint will not cure correctly and will not bond to the roof surface. The paint should be applied very thinly to avoid cracking and should be given 6-8 hours to cure before it can be given it's second coat or walked on. As with all paints, the roof surface should be clean with no dirt or dust.
This is probably one of the simplest energy efficiency projects there is. Please note that this is for flat roofs only that have rubber, EPDM, or rolled roofing membranes. This method should not be used on shingles.