National Coatings Blog

A cool roof is a roof or roofing system that has the ability to reflect a majority of the sun’s heat away from the roof while radiating the small percentage of heat absorbed by the roof surface. Cool roofs come in many different colors; however, a white surfaced rooftop has the greatest ability to reflect the most amount of sunlight away from the building. The concept is similar to wearing a light colored shirt versus a dark colored shirt. The lighter the shirt - the cooler you feel on a hot day, the darker the shirt - the more heat you absorb therefore, the hotter you become.

Cool roofs are favored by building tenants and owners because they are able to keep the inside air temperature of the building cooler without using the air conditioning as often. This is an excellent way for building tenants and owners to save a great amount of money on their energy utility bills and put less stress on their HVAC equipment, allowing them to last longer.

There are several different roofing products available offering cool roof technology, how do you know which one’s will perform best? The Cool Roof Rating Council or CRRC is an excellent independent, non-biased organization that has established a system for providing Building Code Bodies, Energy Service Providers, Architects & Specifiers, Property Owners and Community Planners with accurate radiative property data on roof surfaces that may improve the energy efficiency of buildings while positively impacting our environment. They determines the “coolness” of a roofing product based on Solar Reflectance (SR) the portion of the suns’ heat that is reflected by the roof and Thermal Emittance (TE) the capability the roof surface has to radiate the heat absorbed by the roof. The CRRC records initial testing values and aged (3-year) testing values to determine the capabilities the product in question has to perform. Visit their website (www.coolroofs.org) for a complete rated products directory ranging from asphalt roofing, roof coatings, single-plies, metal and more. 

If you are interested specifically in highly reflective roof coatings and roofing systems, National Coatings has nineteen fluid-applied coatings and systems tested and rated by the CRRC. Our AcryShield roof coatings are some of the highest rated products listed in the directory for solar reflectance, thermal emittance and SRI (Solar reflectance index) the measure of solar reflectance and thermal emittance which is used as a guide to determine how much solar heat the roof is capable of discarding. For a full listing of our Cool Roof Rating Council Compliant Products, click here.

Interested in more information on Cool Roofing? Download our FREE Cool Roof Jargon brochure!

1. The Sun is the Most Damaging Element your Roof Experiences
Cool roof coating systems are light colored roof coating systems designed to reflect the sun’s heat, aka Ultra-Violet (UV) rays, away from your roof. This not only protects the roof from the harsh sun, which causes blistering, splitting, embrittlement, and premature aging but it also lengthens the lifespan of your roof.

2. Buildings with Cool Roof Coatings Remain Cooler in Temperature
The ability to reflect the sun’s heat away from the roof means the building absorbs only a small fraction of the heat, keeping the temperature inside the building cool. (The graph below shows the different surface temperatures that were measured on different roofing systems all in Central Texas on a clear 90˚F day.) 

3. Cool Roof Coating Systems Reduce Energy Consumption and Cost
Studies have shown cool roof coatings allow cooling energy demands to be reduced in buildings by up to 50%. After the National Coatings' Cool Roof was installed we definitely noticed a difference in building temperature. It's not a marginal difference, either. It is between 15-20 degrees cooler inside the warehouse and store." Jerry Moore, Facilities Director at Harbor Freight Tools

4. Lowered Maintenance Costs
Cool roof coating systems add years onto your roof’s life by prolonging the inevitable and normal deterioration a roof experiences. These reflective coating systems provide added UV protection, durability and sustainability to the roofs surfacing allowing the roof to experience less deterioration throughout the years.

5. Roof Coatings Cut Landfill Waste
These cool roof coatings are installed in place, directly over your existing aged, leaking and/or failing roof. There is no need for a costly and timely roof replacement, eliminating any trips to a landfill site.

Do you have more questions on Cool Roof Coatings? Read our Guide, Cool Roof Jargon – What it Says, What it Means and What it Implies

The West Coast as well as much of the country has been experiencing a hot summer with high temperatures, which has lead to an increase in air-conditioning usage.  Building owners and tenants are seeing a spike in their energy costs, as it is expensive to cool the inside of a building during the hot summer months. Cool roofing provides an excellent solution to reducing air-conditioning usage, energy consumption costs and creates a more comfortable work environment.

Data has been around for years proving the effectiveness cool roofing offers to cut energy costs. According to the Lawrence Berkeley National Laboratory Heat Island Group “Black surfaces in the sun can become up to 90˚F hotter than the most reflective white surfaces”. This means a black surfaced roof absorbs a large amount of heat from the sun, causing the inside of the building to become warmer. Cool roofing systems reflect the majority of the sun’s heat away from the building, absorbing substantially less heat into the building, allowing for a cooler environment and increased occupant comfort. Download our FREE "Cool Roof" vs "Normal" Roof Guide for more information on traditional roofing versus cool roofing.

The Cool Roof Rating Council (CRRC) has gathered data on cool roof products since 1998 and found “typical cooling energy savings of 10-30% in cooling energy and an extension in the life of cooling equipment” from using cool roof products.  The CRRC is an excellent resource for credible solar reflectance and thermal emittance values.  They test multiple roofing products to provide accurate data showing the levels of reflectively and emittance values these cool roofing products will provide once installed on your building. National Coatings has several cool roof coatings and cool roof systems that have been evaluated by the CRRC for initial and 3-year aged ratings – check them out here. Make sure you do your research – a cool roof coating with high solar reflectance and high thermal emittance values will provide your building with the best Ultra-Violet (UV) and heat protection from the sun – resulting in cooler ambient air temperature inside the building, prolonged roof life and lowered roof maintenance costs.

To learn more - download “The Ins and Outs of Cool Roof Terminalogy – a FREE Guide to Cool Roof Jargon”