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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Project Profiles: Education Facilities

Maury Hall, U.S. Naval Academy, Annapolis, Md.

TEAM

Roofing Contractor: Wagner Roofing, Hyattsville, Md.
General Contractor: C.E.R. Inc., Baltimore, (410) 247-9096

The project included 34 dormers that feature double-lock standing-seam copper and fascia metal.

The project included 34 dormers that feature double-lock standing-seam copper and fascia metal.

ROOF MATERIALS

Wagner Roofing was awarded the complete replacement of all roof systems. These included an upper double-lock standing-seam copper roof system, a bullnose copper cornice transition, slate mansard, 34 dormers with double-lock standing-seam copper and fascia metal, eight copper hip metal caps and a continuous built-in gutter with decorative copper fascia. Each of the dormers also had a copper window well.

The upper standing-seam roof was removed and replaced with 24-inch-wide, 20-ounce copper coil rollformed into 1-inch-high by 21-inch-wide continuous standing-seam panels that matched the original profile. The eave bullnose, which also served as the mansard flashing, was removed and returned to Wagner Roofing’s shop where it was replicated to match the exact size and profile.

The 34 dormer roofs were replaced with 20-inch-wide, 20-ounce copper coil formed into 1-inch-high by 17-inch- wide continuous standing-seam panels. The decorative ornate fascia of the dormers was carefully removed and Wagner’s skilled craftsmen used it as a template to develop the new two-piece copper cornice to which the roof panels locked. The cheeks and face of the dormers were also re-clad with custom-fabricated 20-ounce copper.

The oversized built-in-gutter at the base of the slate mansard was removed and replaced with a new 20-ounce copper liner custom-formed and soldered onsite. The replacement included a specialty “bull-nosed” drip edge at the base of the slate and an ornate, custom-formed fascia on the exterior of the built-in gutter. The decorative copper fascia included 85 “hubcaps”, 152 “half wheels” and 14 decorative pressed-copper miters. The original hubcap and half-wheel ornaments were broken down and patterns were replicated. Each ornamental piece was hand assembled from a pattern of 14 individual pieces of 20-ounce copper before being installed at their precise original location on the new fascia. The miters were made by six different molds, taken from the original worn pieces, to stamp the design into 20-ounce sheet copper.

In all, more than 43,000 pounds of 20-ounce copper was used on the project.

Copper Manufacturer: Revere Copper Products

ROOF REPORT

Maury Hall was built in 1907 and was designed by Ernest Flagg. Flagg designed many of the buildings at the U.S. Naval Academy, including the Chapel, Bancroft Hall, Mahan Hall, the superintendent’s residence and Sampson Hall. His career was largely influenced by his studies at École des Beaux-Arts, Paris. Examples of Flagg’s Beaux-Arts influence can be found in the decorative copper adorning the built-in gutter on building designs.

Maury Hall currently houses the departments of Weapons and Systems Engineering and Electrical Engineering. The building sits in a courtyard connected to Mahan Hall and across from its design twin, Sampson Hall.

PHOTO: Joe Guido

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An Oceanfront Elementary School Poses Tough Problems, but a Coated Aluminum Standing-seam Roof Passes the Test

Elementary school students sometimes find themselves staring out the window, but few have a view to rival that of the students at Sullivan’s Island Elementary School in Sullivan’s Island, S.C. The school is located on oceanfront property, and when it was time for the original building to be rebuilt, the site posed numerous challenges.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

The original school had been built in the 1950s. It had been designed for 350 students and built on grade. The new school would have to be elevated to conform to modern building codes and service 500 students. The structure would not only have to withstand high winds, severe weather and a salt-air environment, but it also would have to fit into its surroundings. Many residents feared the larger building would look out of place in the cozy beach community. It was architect Jerry English’s job to figure out a way to make it work.

English is a principal at Cummings & McCrady Architects, Charleston, S.C., the architect of record on the project. He worked with a talented team of construction professionals, including Ricky Simmons, general manager of Keating Roofing & Sheet Metal Co. Inc. in Charleston, to refine his vision and bring it to life. English and Simmons shared their insight on the project, and they both point to the building’s metal roof as a key element in the project’s success.

CHALLENGING DESIGN

Cummings & McCrady Architects handles a broad range of commercial, institutional, religious and historic work—new construction and renovation. The firm had done a lot of work with the Charleston County School District over the years, including a small library addition for the original Sullivan’s Island Elementary School after Hurricane Hugo passed through in 1989, and it was awarded the new construction project.

The building’s foundation system had to meet strict regulations regarding resistance to storm surge. The building is elevated on concrete piers, which were topped with a 6-inch reinforced concrete slab. Metal framing was constructed above the slab. “With our building, we had to raise the underside of the structure almost 7 feet above the grade,” English recalls. “What we did is we built it a little bit higher than that so the underside could be left open and used for playground.”

For English, coming up with a design that would reflect the character of the local community was the biggest challenge. To achieve that goal, he broke up the building into four sections and spread them across the site with the tallest sections in the center. “We have four linked segments that transition down on each end to the height of the adjacent residences,” he says.

The roof was also designed to blend in with the neighboring homes, many of which feature metal roofs. “The idea of pitched roofs with overhangs became a strong unifying element,” English explains.

English checked with several major metal roofing manufacturers to determine which products could withstand the harsh oceanfront environment and wind-uplift requirements. “Virtually every one of them would only warranty aluminum roofing,” he says. “The wind requirement and the resistance to the salt air were what drove us to a coated aluminum roof.”

The majority of the panels were factory-made, but the manufacturer supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

The majority of the panels were factory-made, but Petersen Aluminum supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide. Metal trusses give the roof system its shape. English tapped the resources of roof consultant ADC in Charleston and the metal roofing manufacturer to iron out all the details. English wanted to avoid any cross seams in the metal roofing, so he worked with Dave Landis, the manufacturer’s architectural/technical sales manager, to arrange for the longest panels to be formed onsite.

The roof also includes two decks that serve as outdoor teaching areas. These sections were covered with a two-ply modified bitumen roof system and protected with a multi-colored elevated concrete paver system.

Another standout feature is the school’s entry tower, which is topped by a freestanding hip roof featuring curved panels. This roof was constructed with panels that were 12-inches wide. “We found other examples on the island where the base of the roof flares a little bit as a traditional element, and with the closer seamed panels they were able to get those curves,” English says. “It’s a refinement that’s a little different than the rest of the roof, but it’s the proper scale and the fine detailing pulls it together and sets if off from the main roof forms that are behind it.”

PHOTOS: Petersen Aluminum Corp.

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Coating Comes with List of Ingredients

Fluropon Pure is Valspar's newest addition to its Fluropon 70 percent PVDF family of coil and extrusion coatings.

Fluropon Pure is Valspar’s newest addition to its Fluropon 70 percent PVDF family of coil and extrusion coatings.

Fluropon Pure is Valspar’s newest addition to its Fluropon 70 percent PVDF family of coil and extrusion coatings. Formulated with material transparency in mind, Fluropon Pure does not include hexavalent chromium, lead, phthalates and PFOA, allowing the product to meet Living Building Challenge’s Red List 3.0-Compliant requirement. Fluropon Pure delivers the same capabilities of Valspar’s original Fluropon line, including cool roof formulations. Additionally, the coating is trusted to protect buildings against harsh outdoor elements, including humidity and corrosion, dirt, stains and chemicals.

Color Pigment System is Reflective and Fade Resistant

Nationwide Protective Coating Manufacturers Inc. introduces COOL COLORS with ColorActiv Technology.

Nationwide Protective Coating Manufacturers Inc. introduces COOL COLORS with ColorActiv Technology.

Nationwide Protective Coating Manufacturers Inc. introduces a color pigment system of reflective, energy saving colorants with fade resistance called COOL COLORS, with ColorActiv Technology.

The color pigments were originally designed for Military applications. The reduction in surface temperatures provided stealth capabilities against thermographic heat seeking radars to military vehicles and structures. This same technology is now available in ColorActiv Technology pigments for most any of Nationwide Protective Coating Manufacturers Inc., paint or coatings from concrete stains to wall and roof coatings.

Touch the roof or walls of a home or business when it’s been out in the sun for a while, and you will feel it’s hot. In fact, some dark colored roofing can attain a temperature of 190 degrees fahrenheit or more. These materials absorb a portion of the infrared radiation from the sun. This heat buildup transfers inside the structure, increasing cooling costs. ColorActiv Technology now allows for dark colors to have more reflectivity. This lowers the surface temperatures thus lowering heat transfer into the structure. The reflective coatings come in a variety of colors and custom color matching is also available. Depending on your color choice these coatings provide a reflectivity from 23% to 77%.

AkzoNobel Combines Sales and Marketing Teams from Its Liquid and Powder Coatings Businesses

AkzoNobel will combine the sales and marketing teams from its liquid and powder coatings businesses that serve the aluminum architecture and façade and cladding markets. The move reflects the growing importance of powder coatings in that sector, and will help customers and specifiers to make the right coatings choices, says Ben Mitchell, manager, Extrusion Coatings at AkzoNobel.

”Because liquid and powder coatings are not always interchangeable in aluminum applications, it is important for customers to understand which are most appropriate,” he says. “Having a combined team will ensure a unified approach to helping designers, specifiers and fabricators to select the optimal solution for their project.”

The new team builds on an effort to educate industry professionals about powder and liquid coatings choices for aluminum, Mitchell adds. These include an AkzoNobel research paper presented at the Council on Tall Buildings and Urban Habitat 2015 Conference and the AEC Daily continuing education course “High Performance Coatings for Aluminum Fenestration”.

“Specifiers need accurate information on all available products in order to make the best decision for a given application, Mitchell adds. “AkzoNobel prides itself on superior customer service, so our priority is to keep internal experts networked throughout our organization and provide clients with optimal solutions for their specific application, regardless of chemistry or application method.”

AkzoNobel’s products for metal coil and extrusions include TRINAR, CERAM-A-STAR, POLYDURE, ACRA-BOND, INTERPON D3000, INTERPON D2000 and INTERPON D1000.

SOPREMA Acquires Chem Link

SOPREMA, a manufacturer of roofing, waterproofing, wall protection and civil engineering solutions, announces the acquisition of Chem Link, a manufacturer of high-performance, environmentally friendly adhesives, sealants and coatings.

Chem Link will operate as a subsidiary and it will be business as usual for their customers and for the markets they serve. The joining of companies accelerates access to more technology, products and innovation for existing and new complementary markets.

“We’re proud to be welcoming Chem Link into our company, helping SOPREMA further our commitment to providing environmentally friendly innovations that drive our industry forward,” says Tim Kersey, vice president and general manager, SOPREMA USA. “Adding Chem Link is an opportunity for us to provide greater value for all our customers, suppliers and employees.”

“Chem Link’s business principles and core values align extremely well with SOPREMA’s, and being a part of the SOPREMA Group will provide additional resources to assist the company in attaining its fullest potential,” says Phil Georgeau, founder.

Valspar Launches Website for Coil and Extrusion Division

Valspar recently launched a new website for its coil and extrusion division. Keeping the same domain, the new website provides an easy to navigate layout, that is fresh and functional for visitors. From architects to installers, the new design addresses the needs of all end-users.

With a focus on innovation, Valspar’s new architectural coating website allows users to explore colors, industries, products and projects. An updated project gallery showcases the latest innovative uses for Valspar coatings across a variety of industries. Endless inspiration coupled with educational resources provides users everything they need to transform ideas into a colorful reality.

Visitors have the option to browse by color family or special effect to find the best fit for new projects. With more than 20,000 choices and the ability to create custom colors, the new website displays the wide variety of options in an easy-to-preview format.

The new website also houses a wealth of resources for customers to utilize, along with company news and updates. Visitors will find literature on everything from new coatings to Valspar’s commitment to sustainability. The site also features an education component geared towards AIA certification.

RCMA and Members of Congress Address Issues of the Roof Coatings Industry

Members of the Roof Coatings Manufacturers Association (RCMA) met with its members of Congress on Capitol Hill as part of the Association’s Summer Meeting and Legislative Day.

More than 30 RCMA members participated in the Legislative Day, which entailed paying visits to members of Congress and key congressional staffers from their states and districts. RCMA scheduled meetings with more than 80 congressional offices, offering opportunities for manufacturers and suppliers to the industry to communicate to lawmakers the issues of importance to the roof coatings industry.

“The meetings on Capitol Hill gave RCMA members the chance to highlight the issues that are important to our industry,” says John Ferraro, RCMA’s executive director. “It was clear many of the senators, representatives and legislative staffers we met with were receptive to these industry issues, and therefore RCMA will be continuing the dialogue with these congressional offices.”

In particular, RMCA members discussed three main issues of interest to the roof coatings industry: opposing the Environmental Protection Agency (EPA) from further lowering the National Ozone Standard, supporting the Clean Air, Strong Economies (CASE) Act, and advocating for a federal tax credit for reflective roof coatings.

The RCMA opposes the EPA’s proposal to lower the National Ozone Standard. Reductions to the standard have resulted in implementation of hundreds of regulations that created a tremendous regulatory burden. Consequently, the rule forced industries to spend billions of dollars to reformulate their products to achieve new volatile organic compound (VOC) content limits. Over the last few decades, 90 percent of VOC content has been eliminated from roof coatings, and further reduction of VOCs can have a wide variety of unintended consequences.

The RCMA supports the CASE Act (Senate Bill 751 and House Bill 1388). The bill would prohibit the U.S. EPA from lowering the National Ambient Air Quality Standard (NAAQS) until at least 85 percent of counties that are in nonattainment areas have attained the standard.

To incentivize building owners to make the investment to save energy and reduce roofing waste, the RCMA supports the creation of a federal tax credit for reflective roof coatings applied to low slope roof surfaces on multi-family residential, commercial and industrial buildings.

Valspar Acquires Quest Automotive Products and Quest Industrial Products

Quest Specialty Chemicals has completed the sale of the Quest Automotive Products and Quest Industrial Products businesses to The Valspar Corp. The two divisions account for approximately $190 million in sales of specialty coatings in the automotive, transportation and industrial markets. Financial terms are not being disclosed.

“Over the past several years we have successfully built strong teams and grown these businesses into leadership positions in their markets. I’m very pleased that in Valspar we have a buyer who can continue to build the business, brands and customer relationships,” says Doug Mattscheck, president and CEO of Quest Specialty Chemicals.

QAP manufactures automotive refinish coatings, fillers, putties, and other accessories primarily under the Matrix, Pro-Spray and USC brands globally, and QIP serves the professional and consumer markets with aerosol spray products and coatings for industrial applications under the Patriot, Raabe and Precision Color brands.

“Our brands are well recognized and respected, and they compete favorably with premium brands in performance and color-matching at a better value,” says Mattscheck. “They will be a good complement to Valspar’s product range.”

Quest previously announced that it was actively seeking new ownership with the blessings of its equity partners, Audax Private Equity and Moelis Capital Partners. Quest retains ownership of the Quest Construction Products business, which makes and sells roofing systems, reflective coatings for buildings and pavement coatings for the construction market.