The retrofit flashing roofers didn’t know they needed

By Jesse Sanchez. 

The new materials and real-world design of this product make it a standout solution for rooftop venting challenges. 

In an episode of Roofing Road Trips®, inventor, contractor and founder of Garrdal Corporation Dennis Vowles revealed what sets his product apart from traditional rooftop flashing systems and why roofers across the U.S. and Canada are finding new uses for it every year. Garrdal, a two-part retrofit pipe flashing system, is engineered to tackle one of the most frustrating aspects of re-roofing jobs: navigating around rooftop obstacles like electrical masts, concentric vent pipes and tankless water heater exhausts. But it’s not just the design that’s making contractors take notice, it’s the material quality. 

“Plastics have changed in the last 40 years,” Dennis said. “We can make it bulletproof and see-through and that's the same product.” That shift in thinking led to the use of Copaline and Santoprene, materials that Dennis says can withstand temperatures from -70°F to over 200°F. He added, “UV resistance is not an issue. Working in the heat, it'll operate at 210 degrees.” 

But beyond the specs, what’s catching contractors’ attention is how well Garrdal integrates into real-world applications. Dennis noted how the product has been used creatively beyond its original purpose. “There’s a fellow with Platform Pro, he installs swamp coolers and elevated condensers mostly in the south that are rooftop mounted, and he closes in the supports with Garrdal.” 

Even high-elevation contractors have found unique advantages. “A guy in Pinetop, Arizona uses Garrdal to dry in the metal roofs to stop the moist air from getting between the roof deck and the metal he’s going to install,” Dennis explained, pointing out the condensation problems that come with wide daily temperature swings. The product’s real strength, though, may lie in what Dennis called “invisible installation.” Unlike many retrofit flashings that look like afterthoughts, Garrdal’s design is clean and low-profile. He shared, “It looks like a one-piece new construction flashing.” 

Dennis also touched on how Garrdal helps roofers maintain aesthetics and material integrity on insurance repair jobs. “You can repair a foul pipe flashing with Garrdal without having to replace any of the shingles. So, when you do the repair, the roof still matches.” For contractors facing the increasingly complex landscape of modern rooftops, where radon pipes, HVAC systems and solar arrays collide, Garrdal offers a durable, flexible and professional-grade solution. Dennis hinted at more innovations in the pipeline, including versions optimized for steep-slope roofs and potentially new designs if the solar market demands it. 

Read the transcript or Listen to the podcast to learn more about how contractors are using Garrdal in unexpected ways and why it might be the retrofit solution you didn’t know your crew needed!