Paints, Coatings and Liquid Membranes

What are the differences among paints and roof coatings, and what are liquid-applied membranes? The purpose of this article is to define these products and systems to establish guidance for their selection and use and to identify what factors favor specifying a liquid-applied solution versus a prepared roofing solution.

    Paint: A finish where cosmetics are typically a primary attribute. Surface protection may also be a key selling point, but as a rule paint must look good. Paint is sold in specific sheen levels and in a broad range of colors. It usually has limited flexibility, but its hardness provides for exceptional weathering and colorfastness in a thin film.

    Coating: A protective film used to provide surface protection or other resistance property. Color range and appearance are determined completely by performance considerations. A coating generally has an elongation greater than 100 percent, good low-temperature flexibility, is high in solids, and requires a thicker film to achieve long-term weathering and waterproofing.

    Liquid-applied Membrane: A fully reinforced system composed of a fabric and one or more coatings or resins, used to encapsulate and adhere the reinforcement.

Paints, coatings, and liquid-applied membranes are all polymer-rich and share a few key attributes. They are usually based on resins that possess very good weathering resistance and are frequently cross-linked in some fashion to confer toughness and chemical resistance. They are somewhat over-engineered to compensate for the vagaries incumbent with field application.

Paints

Paint applications in roofing are almost exclusively used on steep-slope metal systems for aesthetic or reflective purposes. When metal comes painted from the factory, it is called an Original Equipment Manufacturer (OEM) paint; these baked metal finishes are usually more durable than an aftermarket maintenance coating. Although not intended to improve the water shedding of the roof system, a metal roof may still benefit from the corrosion-inhibiting, temperature-reducing and eye-appealing properties of a paint job.

Steep-slope metal roofs are often important architectural details. Bare metal, despite its luster, has only moderate solar reflectivity and fairly poor emissivity, so it gets very hot. All paints, even dark ones, allow more heat to escape the metal, lowering the peak temperature of the roof. Paints with deep colors can employ special pigments that absorb less heat from the sun.

Most white roof paints are rated for their solar reflectivity and emissivity. Together, these values produce a Solar Reflective Index that can predict the peak surface temperature. In terms of cool roofing, no better improvement exists for metal than coating a rusting metal roof with a white coating. Often these roofs are not well insulated and, as they rust, they become less reflective, holding and conducting heat into the building, which dramatically increases the load on air conditioning. Ultimately, paint can be seen as the first step in a long-term maintenance program that might later involve coatings or membranes.

Coatings

Today, most coatings are based on acrylic, silicone or urethane resins. All seek to extend the service life of the existing roof and, as a rule, prevent the intrusion of water. To do this requires a much higher degree of crack bridging than found in paint. A coating must be able to protect a number of transitions that are subject to cyclical movement: flashing to the membrane, flashing to the structure, joints at protrusions and curbs, and any seams within the membrane. This implies an appropriate degree of low-temperature flexibility, substantial elongation and a thick film. A coating should never be used to overcome a structural issue and, while they must tolerate movement, coatings cannot overcome the limitations of an improperly engineered roof system.

Although many of today’s coatings are sold as part of a cool roof solution, in sunnier climates it is important to recognize that a coating shouldn’t be selected like a paint—strictly on appearance or reflectivity. A coating should provide robust barrier properties, starting with increased water resistance, and often include some combination of chemical resistance (plasticizers, oils, stack emissions) and resistance to abrasion, impact or vapor intrusion (water, oxygen, CO2).

Typically, coatings properties include tensile and elongation, values that are usually reported at standard temperature and humidity. Crack bridging is the key to performance; it’s a function of elongation at a low temperature, tear strength and film thickness. When a material is tested to an ASTM material standard, that protocol will include tear strength, a low-temperature flexibility test and some weathering values. Let’s examine the typical properties and explore what they mean and do not mean.

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Roofing Industry Alliance for Progress Announces Additional Funding for Roofing Research

The Roofing Industry Alliance for Progress announces the addition of four members during 2016’s third quarter, adding $300,000 in funding for progressive roofing research that contributes to the ongoing advancement of the industry.

The Alliance’s newest members are:
Academy Roofing, Aurora, Colo., is one of Colorado’s premier roofing contractors providing commercial and residential roof system replacement and repair in addition to solar roofing, gutter installation and cleaning, new insulation and walkable deck systems. Academy Roofing joined the Alliance at the Governor level.

Bennett and Brosseau Roofing, Romeoville Ill., specializes in in low-slope, steep-slope, metal and green roof system design, construction and maintenance. As one of Chicago’s premier, full-service roofing contractors, Bennett and Brosseau Roofing has a commitment to sustainability and green building practices. Bennett and Brosseau Roofing joined the Alliance at the Governor level.

FiberTite Roofing Systems/Seaman Corp., Wooster, Ohio, manufactures an extensive line of membranes, systems and accessories. FiberTite Roofing Systems/Seaman joined the Alliance at the Regent level.

Georgia-Pacific Gypsum LLC, Atlanta, one of North America’s leading manufacturers of gypsum products and marketers of building products. GP Gypsum joined the Alliance at the Regent Level.

Through the generosity of its members, The Roofing Industry Alliance for Progress commits to the following:
Education and training — Develop programs and projects addressing current and future workplace issues ensuring a qualified and trained workforce for the roofing industry.

Technology — Engage collaborative industry segments to embrace innovation and use technology.

Sustainability — Advocate environmentally sustainable design.

Philanthropy — Enrich the well-being of the roofing community through scholarships, charitable gifts and endowments.

Alliance membership is reserved for those who commit their pledged amount during a three- to five-year period. All members are entitled to participate in the task forces established to guide the Alliance’s agenda, to attend the semiannual meeting of the full Alliance, and other Alliance activities scheduled throughout the year.

Commercial Roofs Will Be More Difficult and Expensive to Insure

Early in the evening hours of June 12, 2014, Abilene, Texas, was hit by a hailstorm that covered approximately 40 percent of the town.

Early in the evening hours of June 12, 2014, Abilene, Texas, was hit by a hailstorm that covered approximately 40 percent of the town.

Early in the evening hours of June 12, 2014, Abilene, Texas, was hit by a hailstorm that covered approximately 40 percent of the town. What made the storm unusual was the size of the hailstones combined with the intensity and duration of the storm. Hailstones varied in size from 2 to well over 6 inches and fell for more than 23 minutes. Most of the stones were frozen rock-hard; some pieces formed when two to three mid-size hailstones froze together.

Some residents reported multiple deck and ceiling punctures with several homeowners reporting stones that penetrated deck and ceiling to smash flat-screen TVs. The damage covered most of the downtown business district; Hardin Simmons and Abilene Christian universities; and a large regional hospital complex, including outlying medical and laboratory facilities. Auto damage was severe and widespread, exacerbated by the large number of visitors gathered downtown for a popular monthly event. There were a few injuries, but no deaths, other than some animals at the local zoo. Initial damage estimates topped $400 million, a sizeable amount for a town of 100,000.

Hailstorms are not unknown in our area though not as common as might be assumed. Since I have been in the roofing business, we have had damaging hails in 1967, 1973, 1988, 2011 and 2014. Our company, now in its 124th year, did not keep records of storms prior to 1967. It has been my experience that no two storms are alike, each taking on a life of its own with regard to how the insurance industry reacts. The last several years, Texas has had major storms in a number of areas, including Amarillo, the Dallas-Fort Worth Metroplex, Austin and Rio Grande Valley. In these areas, roof claims litigation has exponentially increased, driven by a cottage industry of public adjusters, roof consultants, restoration contractors and attorneys, all making a business of inserting themselves between the insurance carrier and the building owner/policy holder. While there can be legitimate need for all these people at times, it does appear some may have crossed the ethical line to shake down insurance carriers with inflated claim demands.

The last several years, Texas has had major storms in a number of areas, including Amarillo, the Dallas-Fort Worth Metroplex, Austin and Rio Grande Valley.

The last several years, Texas has had major storms in a number of areas, including Amarillo, the Dallas-Fort Worth Metroplex, Austin and Rio Grande Valley.

We experienced a little of this activity during our 2011 hail, but it was limited because the hail coverage area included few commercial properties. I was personally aware of several claims made in areas where there was no hail and the damages claimed far exceeded the value of the building.

In response to these perceived abuses, the insurance industry in 2014 has become much more aggressive in its claims handling, especially with gravel-surfaced built-up roofs. Gravel-surfaced roofs remain a significant portion of the roof inventory in this market. Adjusters have been paying for modified bitumen and metal roofing without too much argument. But, since the June hail, we have looked at dozens of buildings with gravel-surfaced roofs that, in our opinion, should be total losses, only to have the adjuster, who is often only vaguely familiar with gravel roofing balk at paying and call in consulting engineers to take sample cuts for lab analysis.

So far, it appears that in the absence of multiple punctures, the assumption is that there is no damage—or at least damage short of a total loss.

So far, it appears that in the absence of multiple punctures, the assumption by adjusters is that there is no damage—or at least damage short of a total loss.

My roofing intuition suggests this activity is a prelude to claims denial. So far, it appears that in the absence of multiple punctures, the assumption is that there is no damage—or at least damage short of a total loss. I can understand the adjuster’s desire to have incontrovertible evidence to base his payment or denial decision, but my experience as a contractor suggests that lab analysis is not foolproof. Some of the tests are based on theories that are at least debatable. The public adjusters and restoration industry have their own labs and tests to compete with the carriers. Regardless of tests, my experience as a contractor suggests that a built-up roof, even with gravel surfacing, is no match for a 20-minute pounding of baseball-sized hail. It is my hope that our industry does not devolve into an adversarial system, which pits dueling laboratories and experts into the claims process.

My suspicion is that it will become much more difficult and expensive to insure commercial roofing, with limits on coverage, much higher deductibles and more specific language to define what is damage. The real loser will be the building owner, forced to assume a much larger portion of the risk.

PHOTOS: JERRY SIEWERT

A Roofer Develops a Solar Solution for Ponding Water on Flat Roofs

The original Sentinel II XD Solar Roof Pump includes a rotatable 20-Watt solar panel.

The original Sentinel II XD Solar Roof Pump includes a rotatable 20-Watt solar panel.

When you say “flat roof”, many people cringe, thinking of stagnant ponding water, health concerns and damaging roof leaks. And it’s not unusual during very rainy seasons to hear about low-slope roofs collapsing under the weight of ponded water.

Auxiliary roof pumps and even solar roof pumps have been around for decades but can be unreliable. Nicholas Bryditzki, a licensed roofing contractor and certified infrared roof inspector, developed the Sentinel Solar Roof Pump because he wanted a more reliable option. “It’s not that I invented it; they already exist but none of them work,” he says. “I went to a premier solar engineer with the concept and said I want to make this thing ‘roofer-proof’.”

To Bryditzki, “roofer-proof” means the roof pump had to be very durable. Consequently, the Sentinel Solar Roof Pump is encased in spun aluminum that is powder coated with a DuPont coating to keep the patent-pending system cool. In addition, patent-pending cold-weather protection ensures the pump won’t freeze and burn out. To further protect the pump, a sensor detects when water needs to be drained, so the pump doesn’t run all the time; it uses a “siphon-effect”, per Bryditzki. The 20-Watt solar panel is large enough to recharge the battery.

The Sentinel II LP Solar Roof Pump is a stationary unit with an embedded solar panel.

The Sentinel II LP Solar Roof Pump is a stationary unit with an embedded solar panel.

“Roofers showed a little resistance to this until I showed them how to actually save a roof and service it until the owner was ready to re-pitch and re-deck or instead of installing expensive new in-roof drains,” Bryditzki adds. “That’s how it’s catching on right now.”

Currently, there are three Solar Roof Pump models available: the original Sentinel II XD Solar Roof Pump, which can be placed where it’s needed; the Sentinel II LP Solar Roof Pump, which is a stationary unit with an embedded solar panel; and Sentinel II XDR Solar Roof Pump, which features a removable solar panel that can be placed away from the pump. “We also developed a pan flashing; roofers install the pan in the roof, place the solar roof pump in the pan and, depending on the roof surface, it will help drain the roof down to virtually no water whatsoever,” Bryditzki adds.

The Sentinel II XDR Solar Roof Pump features a removable solar panel that can be placed away from the pump.

The Sentinel II XDR Solar Roof Pump features a removable solar panel that can be placed away from the pump.

Bryditzki is delighted by the Sentinel Solar Roof Pump’s success during the two years it has been available in the marketplace. He credits the success to the design of the roof pump itself. “The original prototype is still installed and running in the middle of New Mexico,” he says. “I was just out there last month and we tried to break it; we put mud, leaves and rocks in it and it was still draining.”

Learn More
Visit SolarRoofPumps.com.
Call (817) 771-5027.
Watch a Sentinel Solar Roof Pump video.

This “Roofers’ Choice” was determined by the product that received the most reader inquiries from the March/April issue’s “Materials & Gadgets” section.

PHOTOS: Nicholas Bryditzki