Mar 21, 2023 - 8 mins
Up for the challenge: PVDF-based coating system makes tough facade restoration job easier
Originally published on Commercial Paintings Magazine VOL. 2, NO. 4
Some properties, while being striking in their design, pose unique challenges when they at some point need facade restoration. Piercing the Florida skyline, this iconic 18-story, government-owned structure features a highly pitched roofline that makes the restoration in the field particularly difficult.
Constructed in 1989, the building’s aluminum and glass panel exterior lost its luster, and regular facade cleaning proved to be unsustainable over the long term. To help restore the building to its original factory fresh-looking finish, the building’s owners turned to MLD Architects of Tallahassee, Florida, Childers Construction Company (also of Tallahassee), and All Trades Historical Restoration of St. Petersburg, Florida. A full facade restoration, using NeverFade Coatings formulated with Kynar Aquatec® PVDF resin, began in December 2021 and is scheduled to be completed in May 2023.
Hot, Humid Climate Takes its Toll
By 2015, the building’s once bright-white exterior had become dull and muddled after decades of atmospheric pollution. Desiring a facelift for the building, the owners contracted with All Trades Historical Restoration to give the exterior a thorough cleaning. Around the same time, the owners engaged MLD Architects to address leaks coming from unsealed joints between the building’s metal panels and glass windows.
Both of these facade repair and maintenance projects were successful, but several years later, windborne dust and grime, along with relentless UV exposure, continued to degrade the building’s appearance.
“The original factory coating on the metal panels was coming to the end of its lifespan,” said Iain Harnden, RID, LEED AP, Principal, MLD Architects. “While the coating still had good adhesion and wasn’t peeling, the clear topcoat had disintegrated, creating a textured surface that retained dirt.”
This time, the owners decided to initiate a full-scale exterior restoration and turned to their trusted service providers for help. Their goal: a long-lasting finish that would stand up to the area’s unique environmental conditions. When evaluating exterior coating options, project managers discovered that while not all coatings were up to the task, one was: NeverFade Coatings formulated with Kynar Aquatec® PVDF resin.
“In subtropical climates like Tallahassee, buildings are regularly exposed to harsh UV rays, high heat and humidity, which can cause building exteriors to fade,” explained Ron Partridge, Sr. Account Manager, Fluoropolymer Coatings for Arkema. “Even high-performance paints can quickly chalk, fade and degrade. However, coating systems formulated with polyvinylidene fluoride (PVDF) resin technology deliver long-term colorfast performance other coatings can’t.”
Both of these facade repair and maintenance projects were successful, but several years later, windborne dust and grime, along with relentless UV exposure, continued to degrade the building’s appearance.
“The original factory coating on the metal panels was coming to the end of its lifespan,” said Iain Harnden, RID, LEED AP, Principal, MLD Architects. “While the coating still had good adhesion and wasn’t peeling, the clear topcoat had disintegrated, creating a textured surface that retained dirt.”
This time, the owners decided to initiate a full-scale exterior restoration and turned to their trusted service providers for help. Their goal: a long-lasting finish that would stand up to the area’s unique environmental conditions. When evaluating exterior coating options, project managers discovered that while not all coatings were up to the task, one was: NeverFade Coatings formulated with Kynar Aquatec® PVDF resin.
“In subtropical climates like Tallahassee, buildings are regularly exposed to harsh UV rays, high heat and humidity, which can cause building exteriors to fade,” explained Ron Partridge, Sr. Account Manager, Fluoropolymer Coatings for Arkema. “Even high-performance paints can quickly chalk, fade and degrade. However, coating systems formulated with polyvinylidene fluoride (PVDF) resin technology deliver long-term colorfast performance other coatings can’t.”
Arkema’s Kynar Aquatec® PVDF resin is an engineered thermoplastic polymer that promotes weatherability, color retention and abrasion resistance thanks to carbon-fluorine bonds that do not break down under exposure to the elements. It has extreme weatherability similar to that of Kynar 500 PVDF resin-based coatings, which has been used in factory finishes on exterior building materials for decades. Side-by-side southern Florida weathering testing of Kynar 500 and Kynar Aquatec® based coatings over the past 21 years show similar superlative performance with respect to color fade and chalking.
“I was familiar with solvent-based Kynar® 500 technology and was pleasantly surprised to find the PVDF technology is also available for field applications,” said Harnden. “It looked to be ideal for resisting the dirt pickup that plagued the building in the past—a key consideration for this white-colored building.”
Kynar Aquatec® PVDF resin helps APV Engineered Coatings’ field-applied water-based NeverFade Facade Restoration Topcoats resist extreme UV rays, high temperature, humidity and abrasion from salt spray, sand and other windblown particles. It also hinders mold, mildew and dirt pickup for over 20 years—a much longer lifespan than the five-year lifecycle typically seen with high-performance urethanes and acrylic latex paints in climates such as Florida and Arizona. In environments like these, traditional high-performance paints break down under UV exposure, eroding over time and eventually leaving the building’s substrate bare and open to damage from the elements.
“I was familiar with solvent-based Kynar® 500 technology and was pleasantly surprised to find the PVDF technology is also available for field applications,” said Harnden. “It looked to be ideal for resisting the dirt pickup that plagued the building in the past—a key consideration for this white-colored building.”
Kynar Aquatec® PVDF resin helps APV Engineered Coatings’ field-applied water-based NeverFade Facade Restoration Topcoats resist extreme UV rays, high temperature, humidity and abrasion from salt spray, sand and other windblown particles. It also hinders mold, mildew and dirt pickup for over 20 years—a much longer lifespan than the five-year lifecycle typically seen with high-performance urethanes and acrylic latex paints in climates such as Florida and Arizona. In environments like these, traditional high-performance paints break down under UV exposure, eroding over time and eventually leaving the building’s substrate bare and open to damage from the elements.
Teamwork and Technology Combine in Winning Formula
To test the performance of various coatings, the building owner invited four coatings suppliers to install side-by-side mock-ups on the ground floor of the building. MLD Architects and Childers Construction Company worked closely with specialists from Arkema, APV Engineered Coatings, and distributor Lazer Manufacturing throughout the mock-up and subsequent installation process.
“Representatives from Lazer and Arkema showed our firm how well Kynar Aquatec® based coating systems had fared on similar buildings throughout Florida,” said Harnden. “Because the project did not involve costly removal of the existing coating, the mock-up process was crucial to ensuring that the coating would adhere to the previously powder-coated surface.”
“The other coatings failed tape adhesion testing,” added Randall Gardner, Project Manager, All Trades Historical Restoration. “They also lacked the smooth finish and uniformity of the Kynar Aquatec® based coating.”
According to Harnden and Gardner, the choice of NeverFade Coatings was solidified by its 15-year product and labor warranty that covers fading and chalking, plus the fact that it is a one-component water-based system with a long pot life. Tallahassee’s high temperatures and humidity would have caused two-component systems to get tacky quickly, making them difficult to roll on and making application almost impossible. In addition, the water-based Kynar Aquatec® based coating is low in volatile organic compounds (VOCs), meaning building occupants and the painting crew would not be inconvenienced by nuisance odors.
“Representatives from Lazer and Arkema showed our firm how well Kynar Aquatec® based coating systems had fared on similar buildings throughout Florida,” said Harnden. “Because the project did not involve costly removal of the existing coating, the mock-up process was crucial to ensuring that the coating would adhere to the previously powder-coated surface.”
“The other coatings failed tape adhesion testing,” added Randall Gardner, Project Manager, All Trades Historical Restoration. “They also lacked the smooth finish and uniformity of the Kynar Aquatec® based coating.”
According to Harnden and Gardner, the choice of NeverFade Coatings was solidified by its 15-year product and labor warranty that covers fading and chalking, plus the fact that it is a one-component water-based system with a long pot life. Tallahassee’s high temperatures and humidity would have caused two-component systems to get tacky quickly, making them difficult to roll on and making application almost impossible. In addition, the water-based Kynar Aquatec® based coating is low in volatile organic compounds (VOCs), meaning building occupants and the painting crew would not be inconvenienced by nuisance odors.
Application Challenges Quickly Addressed
Everyone involved with the project admits that the building is “tough to paint.” The building’s height and 45-degree roof angle required the use of swing stages for application. Hung from the roof, the swing stages are manned by two crew members, and was supported by an additional crew member on the ground.
“The swing stages only reach to the 16th floor of the 18-story building, so we have an additional crew of up to six rappelers on bosun chairs working on higher levels,” said Gardner. “Given these extreme conditions, we needed a coating formula that would be easy to apply via roller, at the appropriate film thickness and with a quick dry time, but not so quick that we couldn’t maintain uniform coverage across the panels.”
According to Gardner, his crew initially applied the coating in three drops across the large metal panels, working from left to right to maintain a wet edge. However, overlapped roller marks—a big challenge with rolling a coating onto a metal surface in high ambient temperatures—were visible from the ground, prompting the extended project team to brainstorm a way to install the coating in two drops and feather in the overlap lines for a seamless finish.
In addition to the logistical challenges posed by the building’s height and roofline, the crew faced another challenge early in the restoration process. As Gardner’s crew began to pressure wash the building during the surface preparation stage, the dark, tacky caulking material between sealant joints in the roof panels was dislodged, causing streaks down the side of the building. The project team quickly realized that coating over the streaks would compromise the integrity of the coating’s adhesion and thus void its warranty. They therefore had to sand the residue off by hand, wipe the surface down with alcohol to remove any traces, and reseal the roof before proceeding.
“Any time we had even the smallest issue, reps from Arkema, APV, and Lazer were there to help and check on the resolution—from recommending sander grit and tweaking the formula’s dry time, to checking our millage and conducting scratch tests, to final inspection,” said Gardner. “They were there every step of the way, making sure the coating was being applied properly.”
“You can already see the difference in the portions of the building that have been coated,” Harnden added, saying, “and we’ve been able to accomplish everything without undue disturbance to the building’s occupants.”
“We are extremely pleased with the coating and the support we’ve received from Arkema and APV,” concluded Gardner. “We’re looking forward to using the Kynar Aquatec® based coating on different surfaces like masonry, stucco and roofing, and are specifying it for just about every new project we bid on to help keep buildings looking clean and fresh for decades.”
“The swing stages only reach to the 16th floor of the 18-story building, so we have an additional crew of up to six rappelers on bosun chairs working on higher levels,” said Gardner. “Given these extreme conditions, we needed a coating formula that would be easy to apply via roller, at the appropriate film thickness and with a quick dry time, but not so quick that we couldn’t maintain uniform coverage across the panels.”
According to Gardner, his crew initially applied the coating in three drops across the large metal panels, working from left to right to maintain a wet edge. However, overlapped roller marks—a big challenge with rolling a coating onto a metal surface in high ambient temperatures—were visible from the ground, prompting the extended project team to brainstorm a way to install the coating in two drops and feather in the overlap lines for a seamless finish.
In addition to the logistical challenges posed by the building’s height and roofline, the crew faced another challenge early in the restoration process. As Gardner’s crew began to pressure wash the building during the surface preparation stage, the dark, tacky caulking material between sealant joints in the roof panels was dislodged, causing streaks down the side of the building. The project team quickly realized that coating over the streaks would compromise the integrity of the coating’s adhesion and thus void its warranty. They therefore had to sand the residue off by hand, wipe the surface down with alcohol to remove any traces, and reseal the roof before proceeding.
“Any time we had even the smallest issue, reps from Arkema, APV, and Lazer were there to help and check on the resolution—from recommending sander grit and tweaking the formula’s dry time, to checking our millage and conducting scratch tests, to final inspection,” said Gardner. “They were there every step of the way, making sure the coating was being applied properly.”
“You can already see the difference in the portions of the building that have been coated,” Harnden added, saying, “and we’ve been able to accomplish everything without undue disturbance to the building’s occupants.”
“We are extremely pleased with the coating and the support we’ve received from Arkema and APV,” concluded Gardner. “We’re looking forward to using the Kynar Aquatec® based coating on different surfaces like masonry, stucco and roofing, and are specifying it for just about every new project we bid on to help keep buildings looking clean and fresh for decades.”