It’s no surprise that reflective roof coatings remain the fastest-growing product segment in the fluid-applied roofing market. Cool roof coatings can lower energy consumption - a key goal of state and federal regulators - as well as meet more stringent cool roof performance requirements in the building codes.
While it’s true that the high solar reflectivity and emittance of white elastomeric coatings can cut down on air conditioning costs, these products do a lot more than just save energy.
White elastomeric coatings can restore, protect and beautify most waterproofing systems and prolong the life of almost any low-slope roof, including metal.
Even contractors who have shied away from selling restorative roof coatings are seeing the opportunities. Some have even begun installing these products themselves rather than subbing them out to coatings specialists.
The benefits of today’s cool roofing coatings are more than a few mils deep, and reflectivity is often just the beginning of even more dramatic waterproofing performance.
The cool roof coatings market is primarily made up of white elastomeric products and, to a lesser degree, colored coatings that contain infrared reflective pigments. Solvent-based elastomerics, polyurethanes and polyureas all serve similar functions, but there are distinct differences between these products in terms of application, performance and price.
For the roofing contractor, material cost and warranty are the key selling points when considering a cool roof coating. “With one acrylic elastomeric (coating) selling at $75 a pail and another at twice that price, the difference comes down to the percentage of solids in the material,” said one elastomeric coatings supplier. “Go to a home center and you can find acrylics for $75 a pail with 45 percent solids.”
Roof coatings manufacturers agree that a product with 66 percent to 72 percent solids is a good choice for low-slope roofing. In fact, coatings with a high solids content of 70 percent or more can often be warranted for up to 20 years.
Of course, longer warranties require certified installers who can count on strong technical support and inspections from the coatings manufacturer. This also assures the architect and property owner that the contractor has been well trained to install the product.
A well-designed coating, regardless of color, should also be resistant to dirt pickup and be reasonably receptive to cleaning when fully cured. Yet the very properties that allow the membrane to remain pliable through cyclic temperature and climatic changes can undermine this, particularly with lighter colors and in low-slope situations. Dirt pick-up is an issue with any white roof surface, no matter what its make up. This is best remedied by initiating a semi-annual maintenance program that includes thorough cleaning, inspection and repairs.
The Benefits of White CoatingsAs legislators, architects and property owners embrace the idea that building design has a large impact on energy consumption and sustainability, they are also recognizing that white coatings offer big benefits with few drawbacks.
Energy Secretary Steven Chu’s now-famous suggestions for painting the roofs of all buildings white to reduce carbon dioxide emissions and save energy used for cooling has also spurred interest in cool roof coatings.
Energy efficiency initiatives are promoting the use of cool roofs, which may lead to substantial energy savings. In addition, some building codes are now requiring the use of reflective roofs.
“For the past several years, the benefits of roof reflectivity have become increasingly prevalent in the roofing arena,” observed Lynn Picone, senior product manager at GAF Materials Corporation, Wayne, N.J. “Local codes across the nation have embraced reflective roofing with volunteer programs or even code compliance changes.”
If anything, the green building movement is gaining strength every year and raising awareness of the benefits of reflective roof coatings. More generally, environmental awareness of global warming is also raising interest in cool roofs.
“Energy shortages are driving the need for energy savings, and the building industry is also experiencing a greater sensitivity to environmental concerns,” said Kate Baumann, marketing director, Mule-Hide Products Co. Inc., Beloit, Wis. “These two issues are influencing demand for field-applied roof coatings that deliver cool roofs for energy savings as well as sustainability.”
With regard to retrofit applications, the cost effectiveness, proven performance, ease of application, and sustainability of metal roof coatings is another important factor driving demand.
“When applied to metal roofing, coatings can perform several important functions, ranging from aesthetic to weatherproofing,” said Jeff Crace, product services manager, United Coatings, Phoenix. “Coatings offer a choice of color, protection against moisture intrusion, potential energy savings, and structural enhancement, all at a reasonable cost.”
Without question, lowering energy use is not the only benefit that accrues from the use of cool roof coatings. White coatings can extend the life expectancy of many different types of commercial roofing systems simply by avoiding the high roof temperatures associated with exposure to the sun.
The technical term for this exposure is “insolation,” and it is measured in terms of the rate of solar radiation received per unit area (typically expressed in Watts per square meter). Under clear skies, up to 1,220 W/m2 of solar radiation reaches the rooftop.
Heavily insulated roof systems block this radiation from penetrating the building as heat; however, in summer months, convective heat transfer to the surrounding air and radiant heat transfer are inefficient. Consequently, the heat has nowhere to go and roofing membrane temperatures can soar.
While California lawmakers deserve applause for encouraging the use of white coatings to reduce heat gain and lower energy costs, the Big Apple has also seen the benefits of cool roof coatings.
GAF recently partnered with The New York City Cool Roofs Program and donated both materials and labor toward the installation of a reflective coating on a roof owned by the Jewish Association for Services for the Aged.
The NYC Department of Buildings launched the volunteer-based NYC Cool Roofs Program in the spring of 2010 with the goal of installing reflective coating on one million square feet of roofing by October and reducing greenhouse gas emissions by 30 percent by 2030.
The website www.nyc.gov states that “a cool roof absorbs 80 percent less heat than traditional dark colored roofs and can lower roof temperatures by up to 60 degrees and indoor temperatures by 10 to 20 degrees on hot days.”
In fact, an infrared thermometer measured a significant reduction in temperature on the roof at the Jewish Association for Services for the Aged after just one application of TOPCOAT roof coating.
Most people appreciate that white coatings result in savings on cooling costs, but enhanced roof longevity, especially in northern states, can be another major benefit that results in at least as much savings. Without white coatings, roof temperatures can soar in the summer months, especially for buildings in northern climates. This is primarily because these roof systems typically have a lot of insulation to retain the heat during the winter months.
Coatings can also prevent premature roof deterioration by providing a “sacrificial” layer to take the punishment that the elements and the environment dole out.
Coatings can also waterproof and extend the lives of older roofs. Roof coatings can protect the integrity of a metal roof by reducing thermal-shock roof damage. A cool roof coating moderates the excessive thermal expansion and contraction that otherwise could lead to fastener and seal failures.
Standing Up to 6-Inch HailOn May 16, 2010, one of the worst hailstorms in Oklahoma history cut a path of destruction three miles wide and five miles long through Oklahoma City. During a 10-minute period, hail the size of softballs damaged thousands of homes and automobiles.
According to the Associated Press, “The storm produced so much hail it looked like a snowstorm had hit.”
Unfortunately, the storm also zeroed in on a property owner with six large metal buildings spread out over a half-mile area.
“Six-inch hailstones took out every roof within three miles,” said Chuck Musgrave of Musgrave Properties. “The hail came in at a 45-degree angle and we lost the north face of every building in the area. It chewed through roofing and siding and into living rooms and ruined three of my metal building roofs. But the other three with TOPCOAT came through fine.”
It’s a story that some would find hard to believe. Even Musgrave had doubts about the integrity of the coated roofs.
“Three different roofing companies couldn’t find anything wrong with those TOPCOAT roofs,” said Musgrave. Finally, Musgrave asked the roofing manufacturer’s senior coatings expert and a local rep to inspect the three roofs, which totaled almost 15,000 square feet. The roofs were coated six years ago with 18 dry mils in the field and 78 mils on seams and flashing details. However, none of the roofs were under warranty.
“They found a couple of popped fasteners and some dents,” said Musgrave. “Later on, we power washed the roofs and applied more TOPCOAT over the dents.”
Musgrave had to replace some other low-slope roofs affected by the storm, and he said it continues to amaze him that any roof coating could stand up to softball-size hail. “It was one of those ‘100-year’ hailstorms, and one of the most costly to ever hit Oklahoma City,” he said.
Opportunities for ContractorsCool roof coatings are growing exponentially, particularly in the metal roof restoration market. “These products are capturing the repair segment of the roofing market and beginning to corner the energy efficiency retrofit demand as well,” said Luke Sutton, owner of Longhorn Construction, a roofing company in Texas. “As word has spread, building owners are deciding to have their roofs coated even when they are still sound, because they want to extend the lives of their existing roof systems.”
Darren Ward, president of Midwest Roofing Services Inc., Wichita, Kan., agrees that the coatings sector of his business has grown substantially over the past two years.
“It’s a sector of our industry that has a lot of growth potential,” said Ward. “The energy-saving aspect of white roof coatings is one of the most important tools in our marketing program right now.”
When calling on facilities managers, Ward said many are eager to engage in a dialogue about metal roof restorations. One of the contractor’s largest customers has installed “thousands of squares of white roof coatings this year, with ten thousand more squares to go.”
“Especially in the current economy, commercial building owners are deferring major capital expenditures in favor of sure-fire ways to keep using what they have,” added Sutton, “ They consider a metal roof coating to be the next best thing to an entirely new roof.”
Ward has seen the roof coatings market in Kansas become increasingly competitive in recent years, as more roofing contractors invest in their own spray equipment.
“I was one of those contractors who were reluctant to enter the coatings market years ago,” said Ward, “but I came around. More recently, we have also seen coatings grow from a specifications standpoint as well.”
Georgia roofing contractor B&L General Contractors has seen the same thing. Founded in 1989 in Atlanta, the company installs single-ply membranes, modified bitumen and metal roofing, but has seen a strong trend toward the use of cool roof coatings in recent years.
“Quality roof coatings are designed to protect the building against the destructive forces of the environment, while enhancing its appearance and energy efficiency,” said Harold Bolt, president of B&L. “That’s why we offer customers a variety of coatings and membranes to solve their diverse needs. This includes water-based, spray-applied elastomeric coatings.”
According to Frost & Sullivan, the elastomeric coatings market accounted for $620 million in 2004 and has grown into the double digits over the last seven years.
“We’re big believers,” said Ward, “and our customers are as happy as we are with the performance and the tax savings on metal building retrofits.”