RoofViews

Commercial Roofing

Roof to Wall Flashing: Why Details Matter for Single-ply Roofing Systems

By Karen L Edwards

August 06, 2021

Contractor working on a roof

Roof to wall flashing is critical to the performance of every single-ply roofing system. These transition points, where the flat part of the roofing system is tied into the parapet wall, are potentially vulnerable areas for water intrusion. Following the requirements for proper flashing can help ensure that the roof system offers better protection.

How do you install flashing on the wall and roof? Seasoned roofing industry professional Dave Scott of Roofing it Right with Dave and Wally talks through the various roof flashing methods and shares tips for success in a recent webinar.

High Wall Flashing with Screws and Plates

GAF Everguard™ TPO or PVC single-ply roofing systems require flashing between the flat roof surface and the adjoining wall. When using plates and fasteners, Dave refers to GAF detail 317C, High Wall Flashing with Plates and Fasteners.

EnergyGuard™ polyiso insulation should act as the base layer where the roof meets the bottom of the wall. The detail indicates that the insulation should not be greater than 8 inches. As Dave explains, "The reason you don't want the insulation to be thicker than 8 in. is because of the pendulum effect on your fasteners. As the sheet billows or moves, the fastener could lean, causing an egg shape in the hole, and your uplift resistance isn't what it should be."

Using Drill-Tec™ fasteners and plates, a reinforced membrane should be installed over the insulation, 12 in. on center. Another layer of reinforced membrane goes over that, extending up the wall and leaving a 6-in. lap on the roof so that it can be heat-welded into place. The membrane is attached to the wall using the fasteners and plates, again at 12 in. on center for base attachment.

Contractors have an alternate option for the base layer when installing roof to wall flashing: rather than using plates and fasteners, Dave says that opting for a termination bar is an option, as long as it is not higher than 3 in.

The next layer of membrane goes onto the wall, covering the first row of fasteners. Dave explains that up to 24 in. in height, the membrane can be dry hung on the wall. "If you are dry hanging the wall flashing, you are using a 30-in. sheet with a 6-in. lap. Basically, a 30-in. sheet is a half sheet, which is a 5-foot sheet cut in half. You'll have 30-in. flashings up the wall with a 24-in. reveal."

It is crucial to remember to use EverGuard Cut Edge Sealant on all cut edges of the reinforced TPO membrane.

High Wall Flashing with 10-ft. Wide Sheets

In detail 317A, Dave reviews the steps for high wall flashing using 10-ft. sheets.


The steps are similar to those of 317C: a base layer of EnergyGuard polyiso and then a layer of reinforced membrane, attached using fasteners and plates. With 10-ft sheets, the next step requires that EverGuard Bonding Adhesive be applied to the roof and the wall, followed by the installation of the 10-ft wide membrane.

Plates and fasteners get installed at the seam—vertically up the wall at 12 in. on center and a minimum of 10 ft. from any corner or end of wall. Laps are heat-welded, and the process continues until the wall flashing is complete.

"The maximum parapet wall height is not to exceed the width of a 10-ft. sheet," Dave notes. "You're going to have 6 in. on the deck, so on a 10-ft. sheet that gives you 9 [ft.], 6 [in.], so hopefully you can get over the top and install a cap."

A termination bar is acceptable at the top if the sheet is not able to go up and over, according to Dave.

High Wall Flashing with 5-Ft. Wide Sheets

Drawing 317B reviews requirements for high wall flashing with 5-ft. wide sheets of membrane.

It begins in a familiar way: with polyiso and membrane attached with fasteners and plates. The 5-ft. wide sheets are run vertically up the wall and attached with 12-in. on center fasteners also running vertically up the wall. Sheet laps are heat-welded, and the fasteners continue with vertical attachments spaced every 5 ft. along the wall.

Dave likes the versatility of the 5-ft. wide sheets. "The beauty of this is you can go as high as you want. If you have a 15-ft. wall, you can run a five-footer all the way to the top of that 15-ft. wall, and you don't need glue," he says.

Intermittent Fastening and Vertical Sheet Layout

Fastening patterns are key to the success of the system. Detail 317D shows the unique placement of the fasteners as well as how attachment plays a critical role at the corners and the ends of the building.

As Dave explains, "The first three sheets from each end of the building require a row of fasteners, 12 in. on center. Once you reach the interior corner, three sheets out from the corner each way also require the fasteners."

EverGuard cover tape or an 8-in. flashing strip should be installed over the fasteners. However, Dave notes that the fasteners being midway up the sheet make it conducive to using RhinoBond® to avoid penetrating the membrane.

Details matter when it comes to roof flashing. Fortunately, the experts at GAF are on hand to help you determine the best methods and find success. For more information on roof to wall flashing, register to view the full webinar. For additional courses and training opportunities, visit www.gaf.com/care.

About the Author

Karen L. Edwards is a freelance writer for the construction industry and has a passion for roofing, having worked in the industry for 20 years.

Related Articles

Group of Roofing Academy students speaking with Trevor Leeds of BYLTup
In Your Community

Roof Raiser: Trevor Leeds, Elevating the Roofing Industry

The roofing industry has long been a competitive space for contractors, but that healthy competition has helped drive innovation and lift up independently-owned businesses across the country. BYLTup, Inc. is one such business, and CEO Trevor Leeds is committed to elevating the greater roofing industry through everything his company does.After many years in roofing, Trevor partnered with his brother, Brady Woodside, in 2022 and co-found BYLTup, Inc. in Southern California. The pair started from scratch with a blank slate, allowing them to create a culture and brand experience that raises the industry bar, which is important to them.Trevor knew GAF would be a part of their success from the start. He experienced GAF-certified contractors'* support through his previous company and knew the organization's vision and innovation would be key to building the business.Enhancing Roofing Professionalism and SafetyTrevor is passionate about the roofing industry and believes everyone—from manufacturers and distributors to the contractors performing the installations—should work together to create a professional and positive customer experience. Even more importantly, Trevor advocates for the industry's employees and their experiences; safety is an area he wants more people to consider."We need to be making sure that we are taking care of employee safety," Trevor says. "Everyone should be focused on that. Everyone should be concerned about their employees going home safe and sound every single night. When an accident happens in the industry, it's devastating to the business owner and the individual, but it impacts the industry too. We all feel that in some form or fashion."Guiding the Next Generation through GAF Roofing AcademyTrevor's concern for employees and the industry's future led to his involvement in the GAF Roofing Academy. While he didn't have an immediate need for labor in his business, he recognized that taking action now could contribute to building a pipeline of skilled workers that would benefit the roofing industry as a whole.Trevor observed the pool of talent and skilled workers dwindling during his time in roofing. "You have the baby boomer generation that is retiring and a younger generation that wants to get into tech and doesn't want to get into the trades," he notes. "We've got to be able to hire and attract young talent back into the industry or we're all going to suffer."Training Students at the SoCal Roofing AcademyTrevor first learned about the GAF Roofing Academy at a regional conference and stepped up to assist. His company was involved in the first SoCal Roofing Academy, which had three tracks: residential roofing, commercial roofing, and sales training. BYLTup hosted the training's residential portion, and Trevor was impressed by the students' interest and engagement."I was blown away at how engaged they were. GAF had certainly done a very good job screening and prepping these individuals coming in, but they were green," he says. "The trainer was fantastic. The students were shingling after three days."Once the groups completed the tracks, they were brought back together for their graduation ceremony, which was a life-changing experience for many. "I realized that many of these people had probably never been recognized like this before," Trevor says. "They were very proud, holding their certificates and sending photos to their families."Making an Unexpected Hire at BYLTupJust before hosting the SoCal Roofing Academy, GAF Roofing Academy Operations Manager Erick Osuna reached out to Trevor and shared recent graduate Jose Navarro's resume. Jose had completed the commercial roofing training program and stood out to Erick, so he connected with Trevor about possibly hiring him."At that time, I wasn't looking for someone on the commercial roofing side. We weren't really expanding that crew, but we were looking for a production role," Trevor shares. "Long story short, we loved him. He was going to be a great fit for the company, and we hired him as our assistant production manager."Jose excelled on the job. BYLTup quickly moved him into a full production manager role, hiring an assistant to work with him. Trevor says Jose was a great hire. "He's young, he's hungry, he wants to learn. I've never seen another individual in the industry that just wants to learn roofing, and he's a sponge."Committing to Supporting GAF Roofing AcademyTrevor has seen the caliber of students attending and graduating from the GAF Roofing Academy, inspiring his commitment to support ongoing trainings. "I was pleasantly surprised at the overall outcome of the [Roofing Academy] event," he notes. "It encouraged me to the point that I said, 'I want to do this, whether we benefit from it or not, I want to support this at least twice a year, and we want to get more contractors involved in it.'"Want to get involved in supporting the future of the roofing industry? Learn how to participate in a future Roofing Academy and discover the training opportunities available to your team through GAF CARE.*Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program and offering GAF enhanced warranties, which require the use of a minimum amount of GAF products. Your dealings with a Contractor, and any services they provide to you, are subject to the Contractor Terms of Use. Visit www.gaf.com/gaf-contractor-terms-of-use for details.

By Authors Karen L Edwards

June 17, 2024

GAF worker applies StreetBond®, a solar-reflective pavement coating, to an asphalt court.
In Your Community

GAF Partners with the Orlando Magic to Revamp a Sports Court

A newly renovated basketball court at Chambers Park Community Center in Kissimmee, Florida, is a slam dunk for local children and families. GAF is proud to have partnered with the Orlando Magic, AdventHealth, and the city of Kissimmee to make this community's hoop dreams come true.The Chambers Park Community Center is a focal point of the Kissimmee community. The facility offers after-school programs, community events, and camps. It also features a popular neighborhood playground and basketball court where friends and families gather.The collaborative work involved in upgrading the sports court—which reopened on January 10, 2024—is just one example of how the GAF Community Matters program supports and celebrates neighborhoods nationwide.Renovating the Court's Coating and DesignThe inspiration for this project came from wanting to enhance the quality of life for the residents of Kissimmee and provide a safe, vibrant place for families to play outdoors. GAF understands the importance of building resilient communities, so the company donated cutting-edge materials and covered the cost of installation labor to ensure the Chambers Park Community Center's new sports court was a perfect outdoor place to play. To make the asphalt court as safe and durable as possible, GAF used StreetBond® solar-reflective, durable pavement coating with Invisible Shade™. The product can help reduce pavement surface temperatures by an average of 10°F while also helping to protect the pavement from premature degradation due to heat and UV rays.In areas where heat collects, also known as "urban heat islands," there tend to be few trees and minimal shady vegetation, so blacktops and hard surfaces—including parking lots, roadways, concrete recreation areas, and roofs—absorb and release heat well into the evening. Over time, these excess temperatures may contribute to heat-related health effects and negatively impact quality of life for local area residents. This wasn't the first time GAF deployed pioneering cooling strategies to enhance a community's experience. As part of the GAF Cool Community project in Pacoima, California, StreetBond® was used to help diminish urban heat island effects. GAF quickly completed the work in Kissimmee and the facility was opened to the public shortly afterward. The sports court's vibrant design uses custom-made colors inspired by the blue retro logo honoring the Orlando Magic's 35th anniversary court.Celebrating the Court's OpeningCurrent and former Orlando Magic players and Kissimmee's Mayor celebrated the court's unveiling. Team mascot STUFF the Magic Dragon joined the festivities to the crowd's delight.Sixty youth from the Chambers Park Community Center after-school program also attended the court's reopening. The students were thrilled to join in a fast-paced basketball skills clinic. The newly launched court was their chance to meet their sports heroes up close, take photos with them, and enjoy their new playground.Investing in Communities of the FutureThe Chambers Park Community Center's sports court is an important gathering space where youth and their families can safely play, build relationships, and develop their skills.With this project, the GAF Community Matters initiative continues its longstanding partnership in neighborhoods across the country. GAF is committed to making a positive difference by offering roofing expertise, resources, and products to help build more resilient communities.Providing safe, high-quality sports courts where residents can gather helps build resilient communities while promoting active, healthy lifestyles—and GAF is proud to play a role. To learn other ways GAF supports communities across the country, visit www.gaf.com/communitymatters.

By Authors Wendy Helfenbaum

May 28, 2024

Roofers install a GAF EverGuard PVC roofing system.
Commercial Roofing

How PVC Experts Can Help Design Specialized Roofing Projects

With the growing popularity and versatility of PVC roofing systems, GAF has responded by building a team of PVC experts to aid architects, specifiers, and the design community in project success. These highly trained and experienced professionals offer 1:1 support to help answer customers' questions and unique needs when working with PVC on roofing projects, and are here to help you!PVC, or polyvinyl chloride, is a single-ply thermoplastic roofing membrane. The material's characteristics help it thrive in particularly challenging applications. In fact, PVC roofing systems have a proven track record in the US, first introduced in the 1970s after making their debut in Germany a decade earlier.Here's a look at the benefits of PVC roofing systems as well as the guidance and support offered by the PVC experts at GAF.PVC Roofing Advantages and ApplicationsWhile several materials are available for use in roofing systems, PVC has been identified as a particularly long-lasting option. Accordingly, it's steadily grown in popularity nationwide.David Allor, senior area PVC specialist, joined the GAF team in 2022 as a PVC expert. His role was created specifically to support roof designers. Allor has an extensive background in the commercial roofing industry and extensive knowledge about PVC as a high-performance roofing solution."The industry refers to it as a very spec-driven product, and I believe what they're speaking to is a specifier's preference to work with a product that's been well established in the market and field tested," Allor shares. "It has the ability to provide protection against chemical exposure* and stand up well to challenging environments."While PVC may be a spec-driven product, it's also application-driven. Allor explains that PVC roofs may help provide protection for restaurants, food manufacturers, and packaging plants—any facility using animal fats where oils may be exhausted.* He also says that even if the building itself isn't exhausting gases, grease, or chemicals, it's important to consider the buildings and structures that surround it, as their exteriors may be subjected to exhaust that could degrade roofing systems.*Supporting the Design CommunityAs North America's largest roofing materials manufacturer, GAF has equipped teams with the resources and specialists needed to supply customers with more than just products. In recent years, the company built a solid team of PVC specialists that cover the entire US. These specialists assist customers with PVC specifications, roof system designs, and whatever else designers need to ensure successful project outcomes.Whether your project or design firm is based in the Northeast, Southeast, Southwest, Midwest, or West Coast, a PVC specialist is positioned to help. Allor explains the team of GAF PVC specialists is active in the organizations specifiers belong to, including the American Institute of Architects, the Construction Specifications Institute, and the International Institute of Building Enclosure Consultants.Allor describes the team's role as supporting the customer and connecting them to other GAF project support teams that can help. For instance, he said he called on a leading architectural design firm in the Boston area—and two months later, someone reached out for assistance with a specific project needing a tight turnaround."Literally within 12 hours of them reaching out to us, we replied and committed to three pertinent deliverables, those being a Tapered ISO Design Package, an Assembly Letter confirming all FM Requirements, and last but not least, a conference call the next day with the Building and Roofing Science team to go over three critical transitional details." Allor says.Committing to Successful Project OutcomesThe PVC specialists at GAF are focused on one goal: helping architects, specifiers, and the roofing design community achieve successful project outcomes through a high-performing PVC roofing system. With professionals like Allor providing insight and guidance, you can rest assured your PVC project will be in good hands.Ready to get started on your next PVC roofing project? Explore the different PVC roofing solutions available, and visit this page to find your local PVC roofing specialist who is ready to assist you.*GAF warranties and guarantees do not provide coverage against exposure to chemicals, grease, oils, animal fats or exhaust. Refer to gaf.com for more information on warranty and guarantee coverage and restrictions.

By Authors Karen L Edwards

April 22, 2024

Don't miss another GAF RoofViews post!

Subscribe now