RoofViews

Commercial Roofing

How Roof Uplift Testing Can Help Ensure System Performance

By Karen L Edwards

April 15, 2022

Wind sock on a windy day with bird flying in background

Strong winds can create pressure on the building envelope, potentially causing the roofing system to lift. However, conducting roof uplift testing on roofing systems can help predict how a roof will perform when subjected to strong winds.

What Is Wind Uplift?

Wind can exert three types of force on a structure—shear load, lateral load, and uplift load. Although all three load forces can damage a building, the uplift load most intensely affects the roofing system.

The NRCA defines wind uplift load as "The force caused by the deflection of wind at roof edges, roof peaks or obstructions causing a drop in air pressure immediately above the roof surface." However, the same lifting effect that enables airplanes to fly can be devastating for a roofing system. When wind flows under a roof, it pushes upward, elevating the roof membrane. As wind flows over the roof, it pulls the roofing system upward.

Understanding local wind zones and building codes will help determine the requirements needed for the roofing system to best protect the building. This is typically handled by an architect or roofing design professional. James R. Kirby, AIA, GAF building and roof science architect, writes in an article for the American Institute of Architects that the architect's responsibility is to provide wind pressures, whereas the manufacturer must determine the wind uplift capacity of the roofing system.

What Are Roof Uplift Testing Methods?

Professionals use two methods to perform wind uplift testing.

In-Facility Testing

Most manufacturers rely on unbiased, third-party testing labs that are accredited to determine wind uplift resistance of a roofing system. A few of the more well-known facilities include FM Approvals, Underwriters Laboratory, and Intertek. There are a number of industry-accepted testing standards for indoor test facilities, including ASCE-7, ANSI/SPRI, and ANSI/FM 4474.

During testing, these companies subject roof deck mockups (at least 10' x 10') to winds and conditions that mimic various wind speeds with increasing levels of pressure. The roof earns its certification based on its maximum wind performance rating—the level of wind speed that it was able to withstand without failure.

Although lab certifications are important, the building's location, use, occupancy, and wind zone can create unique conditions that may be difficult to replicate in a lab environment.

Field Testing

Roof uplift testing in the field involves placing a dome-like structure measuring 5' x 5' onto the roof surface that subjects the roof to negative pressure forces. The roofing system is observed at different levels of pressure to the point where the system is considered on the brink of failure. This point can vary depending on the criteria being followed—either specified by ASTM or FM Global.

The National Roofing Contractors Association (NRCA) has maintained that field testing is "inappropriate for use" to measure the quality of a membrane roof installation. The organization recommends that contractors avoid jobs that specify field testing as a condition of acceptable installation. A roofing system's ability to pass wind uplift testing relies on many more factors than just the contractor's installation. It's in the contractor's best interest to clearly spell out expectations; the NRCA offers suggested language to use in the project contract.

The NRCA says the most reliable way to determine the quality of a newly installed roof system is by having a "knowledgeable roofing professional" observe the installation. The International Institute of Building Envelope Consultants (IIBEC) agrees, stating in a technical advisory that they recommend observation by an IIBEC Registered Roof Consultant or Registered Roof Observer: "continuous installation monitoring allows for observing the entire assembly process and for corrective action of observed deficiencies as the roof is being installed."

Turn to the Experts

With the number of variables that go into ensuring a roofing system's performance during wind events, it can be challenging to determine the right system and installation method. Not every roofing project will have an architect or design professional behind the specification. In those cases, GAF is here to provide guidance on roofing system options where wind uplift pressures are an important consideration.

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

Aerial shot of roofers repairing homes in the Atakapa Ishak Chawasha community.
In Your Community

Helping the Atakapa Ishak Chawasha Tribe Protect What Matters Most

The Louisiana coast has seen several severe weather events in the last decade, which has made it difficult for many people to rebuild their homes and prepare for future storms. This was the case for the Atakapa Ishak Chawasha tribe, a small community accessible only by boat.The group Rebuilding Together New Orleans recognized the impact a joint effort could have on the region. Together with the GAF Community Matters initiative, and roofing contractor Sunbelt Roofs, the group collaborated with the Atakapa Ishak Chawasha tribe to replace five hurricane-damaged roofs in the tribe's coastal Louisiana homeland.Sowing ResilienceThe week-long roof rebuilding initiative was part of the GAF Community Matters commitment to repair or replace 500 roofs throughout the Gulf region. The goal was to further strengthen and empower the resilience of the families, shelters, and livelihoods of the coastal Atakapa Ishak Chawasha tribe.The Timberline HDZ® RoofCycle™ Series Shingle, which is made with recycled material, was used to protect these homes.Adapting Environmentally"We are stewards of the environment," said Rosina Philippe, a tribal elder of the Atakapa Ishak Chawasha tribe, as she spoke with GAF during the week-long rebuilding initiative. Over a millennium, the tribe has resided in the region, finding all it needs to feed and sustain itself from the environment.However, man-made conditions have significantly impacted the tribe's way of life. The once-forested coastal region is now a salt marsh area, devoid of fresh water and trees, due to levees along the Mississippi River and canals cut through the coastal landscape.These changes have made it "more of a challenge to find the food and plants and medicines that we depend on for our livelihood. But we have been finding them, propagating them, and sharing them with other tribes," said Philippe. "Our way is to accept the natural processes, not change them."Fortifying against Unpredictable WeatherIn addition to the tribe's changing landscape, "what we're dealing with is the unpredictability of the weather," said Philippe. Climate change can cause dramatic temperature swings, which can impact everything from the life cycle of the tribe's crops to the protection of its homes.Situated at the southeasternmost lands of Plaquemines Parish, fingerlike marshland trails out into the Gulf. The homes in the Atakapa Ishak Chawasha community are built on stilts along these watery paths and are accessible only by boat. These homes are often the first line of impact with hurricanes that rip through the Gulf of Mexico.Hurricane Ida—the fifth most expensive hurricane in US history—dealt the water-based community a devastating blow. For nearly two years, the hurricane's impact on tribal homes compounded with each subsequent storm because there wasn't an opportunity to repair its damage.Partnering for StrengthFortunately, through collaborative efforts between the Atakapa Ishak Chawasha, Rebuilding Together New Orleans, GAF, and Sunbelt Roofs, the opportunity to build tribal community resilience through new roofs became available. Bringing in roofing materials and roofers by boat, the Sunbelt Roofs team removed the storm- and hurricane-damaged roofs, repaired roof decking as needed, and installed new GAF roofing systems on the five homes.The roofing materials installed are designed to protect against volatile weather like hurricanes. To provide long-lasting protection against leaks and wind-driven rain, Sunbelt Roofs installed StormGuard® Film-Surfaced Leak Barrier and FeltBuster® Synthetic Roofing Felt. To help prevent shingle blow-off due to high-speed winds, Sunbelt Roofs installed Pro-Start® Starter Strip Shingles.The Timberline HDZ® RoofCycle™ Series shingles that were installed have Dura Grip™ Adhesive, which provides advanced protection from shingle blow-off and wind-driven water creating leaks or water damage.Building Communities TogetherThe initiative with the Atakapa Ishak Chawasha tribe is part of a comprehensive $25 million GAF commitment through 2025 to leverage roofing expertise, resources, and products to help support and empower resilient communities' fundamental needs. Through grants, in-kind donations, and hands-on support, GAF Community Matters is partnering with area organizations that know their communities' needs best.In the Gulf region, GAF partnered with organizations such as Rebuilding Together New Orleans, SBP, Good360, Habitat for Humanity, and Team Rubicon to rebuild or repair 500 Gulf region roofs, train a skilled workforce, and empower communities hard-hit by severe weather.Moving ForwardDespite the challenges of climate change and the changes in their physical landscape, Philippe said, "We still live a rich life here." As the environment changes, the tribe adapts, a demonstration of its resiliency. "These are the new norms that we are having to learn and document and chronicle, this is the information we'll have to pass onto our future generations so that they can continue to inhabit this area," she explained.To learn more about the resiliency work at GAF or to get involved, explore the GAF Community Matters initiative. Special thanks to the Atakapa Ishak Chawasha tribe, a member of the First People's Conservation Council of Louisiana.

By Authors Annie Crawford

April 16, 2024

GAF Roofing Academy Graduate holds up his certificate of achievement.
In Your Community

How Attending the GAF Roofing Academy Changed One Graduate's Life

Meet Austin Teague, recent GAF Roofing Academy graduate who shares his transformational journey from ball field to the roof. Prior to the GAF Roofing Academy, he was involved in sports, worked in customer service, but lacked the experience needed to break into the roofing industry. Once he graduated from the GAF Roofing Academy, doors were then opened for him, leading to well-paying jobs as an installer and later as a salesperson, where he is currently on track to meet his financial goals.Attending the two-week program proved to be a life-changing decision for Austin, providing him with the tools and confidence needed to succeed. The course not only equipped him with technical expertise, but also instilled in him the ability to educate customers effectively. Take a listen as Austin shares his story of how he found clarity and direction in his professional life, enabling him to thrive in the industry and build a successful future for himself and his family.Are you interested in a career in the roofing industry? Look for a Roofing Academy course in your area. Video TranscriptMy name is Austin Teague. I'm originally born in Tyler, Texas. Moved to Washington when I was a kid at ten. Well, prior to joining the Roofing Academy and, you know, taking my skills to that test, I was sports, strictly sports. Everything in my life I would, you know, I'd work a customer service job. I was in the, you know, the retail industry. I worked at Walgreens, but my personal life was hectic. It was football practice, baseball practice. It was always something going on.There was always something to do. Everything when it comes to roofing, for me, started after the Roofing Academy. When I tried to get into the roofing industry before going to the Academy, nobody wanted me because I had no experience. They're going to have to train everybody on the job. But because of the roofing academy, because I knew what I was going to do day one, I knew what my job was. I couldn't run into any hiccups because I knew what showing up day one was going to look like.[00:00:56.770]So they gave me a GAF certificate with my name, the location I trained out of, and then when I graduated. And what I did with that is I took it to every single applicant or job interview I had because I wanted them to know that I have this certificate. Not saying I have it, but also bring it, so they can see it.After the academy, I landed a job at 28 an hour as an installer, which is substantial in this living, making life, making payments. And then after that, I got bumped up to 32 an hour when I was working in New Mexico. And now that I'm sales, I'm straight commission. But in this month, I'm on pace to hit 20,000. Our goal at Tristate is to educate the customers firsthand. So being at the Roofing Academy allowed me to know roofing like the back of my hand. As an installer, as a sales, as an owner, you got to see the value in the systems. And it allowed me in my head to build those value, actually explain it to the customers. Where is this number coming from? Well, it's coming from this material because this material is going to cost more, of course, but it's obviously better.[00:01:58.920]I think someone coming to the Roofing Academy right away, no experience, is going to set you up for success. That's what you want. You want to be set up for success. You want to be as many tools as you can in your tool belt to get you to that point you want to be in life. And showing up to the Roofing Academy, it changed my life drastically. I didn't know what I was going to do. I literally didn't know, if roofing wasn't the pathway for me- what was the next plan?I was just grateful. I mean, I was one day on indeed looking for jobs and I saw the Roofing Academy post on indeed looking for academy students, and I thought, why not? What's two weeks out of my life that I get to change it? If I get an opportunity to change it and that two weeks changed my life. There's no time wasted. You're here from nine to three or nine to four at the latest for your classes.You're with guys that you actually enjoy being around. The guys in my class or in the class today, they're fun guys. They all get to make mistakes and learn from each other. And it just makes me grateful that I got that opportunity to make something of myself. I'm not just another guy on the street.[00:03:00.340]I don't know what my life's going to look like in the next six months, but I guarantee it's not going to slow down. I'm going to work harder than ever. I know I got two kids at home. I have something to push me. I would say that all the success started with the Roofing Academy because my life before the Roofing Academy was kind of on a snowball effect. It had started from when I left college and then came home and it kind of just started snowballing. One thing after another was another problem, another problem. Bills at 18, going into debt. You're 18, your life isn't, you're going to ruin your life already. So you got to figure some out. And I figured it out. I got lucky enough that I found GAF and you know they still treat me well to this day. I have my Academy teacher's phone number and I call them up and help him out from time to time, and he helps me out from time to time.We still get along. And it was two weeks of my life that I knew the guy, and he still gives me a call and checks up on me and tries to: How are you doing in roofing? You still in roofing? You still making a name for yourself? You still doing what you said you were going to do? And I am. It's just good to have someone to talk to. Even if you're in this industry for ten years, I guarantee you GAF CARE will probably still give you a call and check on you. That's just what they do.

By Authors GAF Roof Views

April 12, 2024

GAF Sustainability Award winners holding their award.
In Your Community

GAF Celebrates Major Strides in Manufacturing Sustainability

Manufacturing sustainability is a top priority for GAF. In 2022, the company announced its 2030 Planet Goals to "focus on operational improvements, product transparency, and the introduction of circularity in the asphaltic shingle industry."Looking to lead positive change while considering the long-term impact of its business on the planet, GAF identified several goals, including:Diverting 1 million tons of roofing materials from landfills while integrating recycled shingle materials into new shingle productsDiverting 80% of manufacturing waste from landfills, recycling all shingle and TPO scrap that results from the manufacturing process, and recycling or reusing fiberglass mat scraps and coresReducing embodied carbon and operation carbon throughout its manufacturing and operationsAchieving Environmental Product Declarations for its core products, conducting life cycle assessments, and generating 2.5 GW of power from solar roofs in partnership with GAF EnergyMeeting these goals takes time, resources, innovation, and ingenuity, all backed by a team working to build a better world. Every GAF location is striving to meet the company's goals. Looking back on the progress made in 2023, some impressive accomplishments are bringing the company closer to achieving full manufacturing sustainability.Residential ManufacturingThe GAF Mt. Vernon, Indiana, shingle manufacturing plant worked toward achieving sustainable operations through robust recycling efforts. The team established a shingle recycling outlet estimated to divert thousands of tons of asphalt shingles from landfills annually. This has eliminated thousands of dollars in disposal fees and reduced transportation costs.The Mt. Vernon staff found creative ways to keep complex waste materials out of landfills, including working with a local golf course that could take the plant's waste sand. The team implemented an internal recycling program that includes cardboard and packaging materials, increasing its waste diversion score.Commercial ManufacturingAt the Gainesville, Texas, plant that manufactures TPO and Polyiso, team members earned the area's first waste diversion certification for both products' waste streams. They also earned a recycled content certification for each.The plant established a trial program with a plastics recycler to reprocess TPO skin material for reuse in manufacturing new material. Recycling and reusing would divert thousands of tons of waste from landfills and use recycled materials in manufacturing flexible TPO for flashings.The plant also developed a program with a local recycling company that serves as a single source to take its pallets, large cardboard boxes, facers, paper, and plastics.Sustainability All-StarsRecycling and manufacturing sustainability programs wouldn't be possible without the people behind the initiatives. GAF is proud to spotlight these individuals who went above and beyond to meet the company's sustainability goals.Ben AnselmanAs part of the Mt. Vernon team, Anselman was critical to starting the plant's core recycling program. He initiated repairs to an existing baler and established a program for recycling the super sacks. His creativity sparked the partnership with the local golf course to divert aggregate waste from landfills. In addition, he was the champion for the shingle recycling outlet project and repurposed an existing compactor to reinstate a cardboard recycling initiative.Christina Talladira and Amy WilsonThese teammates lead the core recycling program at the Tampa, Florida, manufacturing plant. They worked together to establish aggregate and shingle recycling programs with their local recycling company. Talladira and Wilson consistently look for ways to divert waste streams from landfills. They also handle the administrative needs accompanying these programs, including scheduling loads and tracking waste.Jeremy TisdaleAt the Tuscaloosa, Alabama, plant, Tisdale took the initiative to improve its core recycling program and set up a cardboard recycling program. He also championed a baler trial for glass mat cover and core waste, developing standard operating procedures and a job safety analysis. He was the innovator behind diverting the plant's plastic waste from landfills. He created a program where stretch film and shingle bundle packaging waste is saved in Gaylord boxes and then baled whenever the plant has downtime.Pete WeyrensIn Gainesville, Texas, Weyrens is the champion behind the plant's recycling efforts, establishing relationships with the local recycling company. He also organized the flexible TPO skin material trials. This effort will divert thousands of tons of waste from landfills and use recycled materials to manufacture flexible TPO for flashings.Leslie PeelsAfter the plant in Cumming, Georgia, saw a drop in its year-over-year waste diversion rate, Peels stepped in to turn those numbers around. Leading the effort to separate recyclable materials from regular waste, the Cumming location saw an impressive increase in keeping waste out of the landfill. Peels also set an example in data collection and analysis to keep the plant's sustainability goals on track.TJ Jenkins and Todd WinsteadJenkins and Winstead represent the TPO team at the Mt. Vernon manufacturing plant. Working together, they used their knowledge and experience in the TPO manufacturing process to help earn the plant's recycled content certifications. They also found a way to divert calcium chloride from local landfills and continue to work closely with the sustainability team to support waste diversion efforts.Sustainability PromiseGAF is committed to "Protect What Matters Most," and that includes people, communities, and the planet. Its sustainability promise is an opportunity to invest in a healthy future for everyone. Learn more about that commitment in its sustainability report.

By Authors Karen L Edwards

April 11, 2024

Don't miss another GAF RoofViews post!

Subscribe now