How does a reflective roof coating make a roof “cool?”
Nearly any roof can be converted into a “cool” roof by applying a reflective roof coating. This can be achieved at any time during the life of the existing roof. These coatings can be applied to new and existing dark-colored roofs. A reflective roof is defined by ENERGY STAR® as one that has properties of at least 65% reflectivity and 50% emissivity after 3-year aging. It reflects solar energy back into space so the roof surface remains cooler. A “black” roof becomes incredibly hot in the heat of summer, with this solar energy getting absorbed into the building. The installation of a reflective coating not only reduces the surface temperature and heat transfer into the structure, it also acts as the first line of defense against water penetration.
What are the benefits of using a reflective roof coating?
Architects and Roof Consultants can specify a simple, green, sustainable solution that saves building owners and facility managers money, eases installation for contractors, and can meet, satisfy, or contribute to Title 24, LEED, and other green rating system requirements.
Because the reflective roof coating cools and protects the roof surface, it:
- Reduces the temperature inside the building it covers by 6-9 degrees
- Reduces the roof surface temperature by up to 50%
- Increases the effective “R” value of insulation
- Increases the efficiency of roof-mounted HVAC units
- Saves on the cost of air conditioning the building
- Results in lower energy costs overall to the building owner by reducing the “peak electrical demand” level
- Creates a more comfortable environment in areas where there is no air conditioning
- Slows premature aging of a roof due to high surface temperatures and UV degradation
- Results in reduced overall roof life-cycle costs
- Reduces respiratory health risks and the risk of heat-related deaths, especially in a “Heat Island” area
- Offers your clients a cost-effective method of meeting their roofing needs
And it’s environmentally friendly (“green”) because it:
- Reduces landfill materials – at least 10% of landfill waste is made up of roofing materials
- Saves energy, both for the building owner, and for the utility supplier
- Results in a reduced carbon footprint of the building by reducing the CO2 emissions
- Minimizes the overall environmental burden
Is the cost of applying a reflective roof coating a good investment?
Yes, applying a reflective roof coating is an excellent investment.* If the installation costs for a reflective roof coating (which vary) are slightly higher in certain situations, the long-term benefits can easily offer an attractive return on the installation investment, by providing:
- Longer roof life, better durability—coatings protect the roof substrate from destructive UV
- Reduced maintenance costs over the life of the roof; and coatings can provide the added bonus of being a water-resistant barrier
- Better budget management due to predictable life extension of the roof (the opportunity to re-coat the roof rather than replace it)
- Reduced installation risks
- Minimal disruption to the occupants, operations during application, construction process, saving money in areas other than the roofing materials and application itself
- A more desirable and comfortable work environment inside the building
- Opportunity for energy credits, tax savings, rebates
*Coatings are considered “restoration” and not a new roof system installation. Therefore they may usually be expensed in the fiscal year during which they are applied instead of amortizing the cost over the life of the roof (as in a new membrane installation). This can be a huge tax benefit to some building owners. Check with your CPA or CFO to properly apply this information to your own roof situation.
Is a special contractor required to install a reflective roof coating?
An experienced roofing contractor should apply the reflective roof coating. Although the coating may look like ordinary architectural coating, successful application and long-term performance requires proper preparation, repair of leaks or damaged areas, and ultimately proper selection of the correct primer and coating system.