RoofViews

Toitures commerciales

Matériaux de toiture résistant au feu pour toitures commerciales

By Dawn Killough

Le 01 septembre 2021

A red fire alarm on a gray wall

Lorsque l'on conçoit un système de toiture à faible pente, il est important de tenir compte de la capacité du système de toiture à résister à un incendie voisin. Il existe maintenant des produits qui peuvent doter votre système de toiture de l'indice de résistance au feu nécessaire tout en aidant le bâtiment à obtenir des crédits en vue de la certification LEED.

Fire Ratings and Low Slope Roofs

Specifying a particular fire rating requires consideration of the fire resistance performance of each component of the low-slope roof system.

Starting from the bottom, the roof deck should be made of non-combustible materials such as steel, gypsum, or concrete whenever possible. However, many commercial buildings are constructed of wood, meaning that the roof deck is usually plywood or OSB. If this is the case, a fire protection coating can be applied to keep the flame spread down. When used in certain Class A roofing systems, a fire protection coating can help maintain the Class A rating when tested in accordance with industry standards ANSI/UL790 Class A or ASTM E108. Adding a cover board to a roof system can also help the fire rating, as it helps block fire penetration to the insulation below.

Next, when applying an underlayment layer, choose one that provides additional protection against fire. Products such as fire-retardant plastic sheeting or fiberglass-reinforced underlayment will provide moisture protection for the deck, as well as fire protection. These products can help protect buildings against flame spread and penetration into the building, and can help improve the roof system's fire rating.

When it comes to insulation, polyiso insulation (polyisocyanurate insulation) can also help provide fire protection for commercial roof systems. Its strong chemical bonds give it improved high temperature resistance, and therefore improved fire resistance performance. Gypsum-fiber roof board products are also frequently used in low-slope roofing systems to achieve a Class A fire rating when tested in accordance with industry standards ANSI/UL790 or ASTM E108.

As for roofing membranes, PVC has certain inherent characteristics that may help provide additional fire protection to a roofing system. If fire resistance performance is an important consideration for a roofing system, PVC may be a good option.

Obtaining LEED Credits for Your Fire-Rated Roof

For projects that are seeking LEED certification, designers should pay careful attention to the ingredients that make up each component of the roof system. Many of the components may be available without environmentally harmful chemicals and additives, but you'll need to do your research to be sure.

Low-VOC (volatile organic compounds) coatings and adhesives can be found by reviewing product data sheets to find the product with the lowest levels for your application. Additionally, if fire resistance performance is an important consideration for a roofing system, you might also want to consider mechanically attached or other non-adhered systems.

When selecting a polyiso insulation, look for options that do not contain halogenated flame retardants, which may be hazardous to the environment. You should also look for options that do not contain CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), or Red List chemicals where possible.

Another category of LEED certification that applies to a roof assembly is energy efficiency. Materials that provide a higher R-value can help keep conditioned air from escaping the building, which in turn can help reduce the strain on building heating and cooling systems. Sealing all gaps and flashings will also help reduce air leakage (and can help prevent water damage, as an added win).

For detailed information about how GAF's products can contribute to green building rating systems such as LEED, you can visit GAF's sustainable product platform, gaf.ecomedes.com.


In summary, your customers can obtain desired fire ratings for their roofing system while also selecting products that may help the building achieve LEED certification. They don't have to choose one or the other. There are plenty of products available that offer fire protection and don't contain chemicals that may be harmful to the environment. Just be sure to thoroughly research materials before specifying them, so you know you are selecting products that are suitable for the specific needs of the project. To look up fire ratings for your specific roofing system, you can visit the UL Product iQ certification directory or FM's RoofNav.

About the Author

Dawn Killough est une rédactrice indépendante pour les domaines de la construction, des finances et de la comptabilité. Elle est l'auteure d'un livre électronique sur la construction verte et écrit pour des sites Web sur la technologie de la construction et les bâtiments verts. Elle vit à Salem en Oregon avec son époux et quatre chats.

Articles connexes

Volunteers in GAF Community Matters shirts stand in front of a home build site.
Dans votre communauté

2024 Habitat for Humanity Carter Work Project in Twin Cites GAF Hometown

Under sunny blue skies, GAF hometown workers from Minneapolis joined over 4 000 Habitat for Humanity volunteers to donate their time and energy to the 2024 Carter Work Project in East St. Paul, Minnesota.The landmark 40th anniversary of the Carter Work Project celebrated former President Carter's 100th birthday. It also heralded the completion of 30 new all-electric homes in The Heights-the largest affordable housing development yet for Twin Cities Habitat-and marked the first installation of GAF Timberline Solar™ Energy Shingles.Supporting the Carter Work Project's PurposeGAF and the Habitat Carter Work Project share a common mission-to protect what matters most and bring people together to build homes, communities, and hope. Safe, secure, affordable housing is one of the surest routes to building resilient communities.Former President Jimmy Carter and former First Lady Rosalynn Carter were early champions of affordable housing. In 1984, they partnered with Habitat for Humanity to lead an annual week-long housing build. The momentum grew, and now, four decades later, over 100 000 Habitat volunteers have helped construct over 4 400 affordable homes for families in need.Each year, GAF volunteers travel from around the country for the Carter Work Project. GAF Community Matters also donates roofing materials, training, and installation expertise. Since 2011, GAF and its national network of certified contractors have supported roofing installation on over 3 800 roofing systems in collaboration with Habitat for Humanity, impacting more than 15 500 individuals.Building Resilience in MinnesotaThis year was particularly special thanks to first time solar shingle installation at a Carter Work Project. Even more, the project's location was in a GAF hometown and local GAF employees were on-site to volunteer.Benefitting Homeowners by Going Solar"We're donating 40 roofing systems and 40 solar energy systems from GAF and GAF Energy," says Jake Pream, a territory manager for GAF Energy in Minnesota.In addition to energy production, the beauty of the GAF Timberline Solar™ Energy Shingle is its simplicity. The nailable shingles are "just like your typical Timberline HDZ® Shingles," says Fan Ulacia, Director of Product Deployment Applications for GAF Energy and one of the minds behind the solar shingle design. "They're simple enough to install with a nail gun, but they produce energy." For Ulacia, improving access to solar energy, giving back to the community, and helping homeowners gain energy independence make GAF Energy a great fit for the GAF Habitat partnership."The solar-powered roofing system will make these homes more resilient, generate energy, and be a long-term benefit to Habitat homeowners by helping to offset their energy costs," adds Jeff Terry, vice president of corporate social responsibility and sustainability at GAF, who has volunteered at the Carter Work Project for 26 years.Helping a GAF HometownThe Twin Cities Habitat build is also special because it means the Carter Work Project takes place in a GAF hometown. As Pream, a St. Paul native, puts it, "I have friends and family quite literally a few houses down."The Minneapolis GAF manufacturing facility opened in 1935, and "it's something we're really proud of," says Austin Owens, a local GAF technical manager. Over the years, "we've made improvements to equipment and operations and made changes to help the environment and sustainability. We try to help the community as much as possible."Like many GAF volunteers at the Carter Work Project site, Joey Och, a GAF plant process engineer, grew up in the area. "Affordable housing is something Minneapolis and St. Paul have been pushing for," says Och, "so it's nice to be out here and help. Affordable housing brings more people into the community."With GAF donating roofing and solar energy systems for this year's project, safe and affordable homeownership, with reduced energy bills, will be accessible to more people.This housing security helps strengthen the community. The area may experience severe weather and its share of hardship, but "there's a lot of resiliency in this community," says Owens.Carrying On the Carter Work Project in 2024 and BeyondFor many reasons, the Carter Work Project inspires repeat volunteers. "Community does matter," says annual participant and GAF CARE Learning and Development Instructor Michael Humenik. "It's just fun to volunteer. I look forward to coming out every year."Habitat homeowners who return each year to volunteer are the true testament to the transformational power of access to safe, affordable housing. LeAndra Estes brought her hard work and a big smile to the week-long Twin Cities build. Estes is an annual volunteer for the program that changed her life. "I need and I want to give back to Habitat for Humanity, to the affiliates and partners, and to the future homeowners to come," she notes.Estes puts into words the value of affordable housing and how the benefits ripple far beyond the home. "When you have a home, you don't just have that home and your family. Your community also becomes your family," she explains.Although former President Carter has retired his tool belt after decades of humanitarian service, he surely must have been proud to see his legacy continue to evolve, especially with the revolutionary new solar shingle that supports homeowners' financial independence.Ready to get involved? Explore the Habitat for Humanity GAF Contractor Program and change lives for the better, starting today.

Par les auteurs Annie Crawford

19 décembre 2024

GAF Employee on the job
Dans votre communauté

How GAF's Co-Op Program Makes a Difference in Students' Lives

As part of its effort to build resilient communities, GAF provides students across the country with opportunities to gain work experience and hands-on training. The GAF co-op program offers participants autonomy and leadership in project management, engineering design, budgeting, project installation, and more.Over the years, the GAF co-op recruiting program has helped students advance academically, grow professionally, and earn competitively while working full time with North America's largest roofing and waterproofing manufacturer.How the GAF Co-Op Program WorksThe program gives students high-impact, hands-on experience in the manufacturing sector. They perform meaningful work alongside supportive GAF mentors and senior leadership while earning a competitive wage. Participants can also receive credits from their university, which they can apply to their coursework.Differences between a Co-op and an InternshipInternships and co-ops have a few notable differences. At GAF, the main difference is the length of time. Internships at GAF usually last 10 weeks, but the co-op program is six months. While internship programs often allow students to stay enrolled in school and complete coursework as they gain professional training, co-op participants must take a semester off to gain full-time work experience.Not all companies pay internship participants for their work. However, at GAF, both interns and co-op students are paid competitive hourly wages. GAF also offers financial relocation assistance for qualifying co-op program candidates.Finally, participants in the GAF programs are there to learn real skills that will help them advance their future careers. GAF interns and co-op students are given the same responsibilities, and chances to collaborate on major projects, as full-time employees.Recent GAF Co-Op Success StoriesMin U, a mechanical engineering student at the University of Maryland, says he "fell in love with manufacturing" thanks to his placement on an engineering project. The experience gave him a firsthand account of the role engineering plays in manufacturing safety, profit, and operations. This ultimately led him to shift his career goals from construction management to manufacturing engineering.When Dante Stellar, an industrial engineering student at Virginia Tech, met GAF representatives at a career fair, he says he didn't expect to become a self-proclaimed "nerd for shingles" and develop a passion for manufacturing. However, that's exactly what happened. And that newfound passion paid off when Dante won Student of the Year from Virginia Tech's Cooperative Education and Internship Program. Dante notes he's now eager to return to GAF and aspires to become a manufacturing leader in the world of shingles.Michael Hesseltine, an electrical engineering student at Texas A&M University, chanced upon a GAF co-op recruiting listing online. After a series of interviews, he landed a project engineering co-op in Ennis, Texas. Working with the Ennis team on major projects solidified his manufacturing engineer career goals.Co-Op Students Complete Meaningful WorkStudents in the GAF co-op program are involved in meaningful projects and get to see their work's impact on day-to-day operations.During his time in Ennis, Michael designed a baler that compacts fiberglass scrap, reducing site disposal trips and costs. He also oversaw renovations of the site's maintenance mechanical break room from start to finish. He notes that his favorite contribution was helping design the electrical system for a dewatering press.In Baltimore, Min's core project was ensuring site compliance with state regulations for discharging stormwater runoff. Min managed all the project contractors and budget with his manager's and mentor's support. Throughout his time there, Min was exposed to Lean methodologies, 5S, risk mitigation, insurance compliance, cost control, and procedure standardization. He gained an overall understanding of manufacturing equipment and business.At the Tampa plant, Dante worked on a rock pad storage expansion project and installed a starwheel machine guarding the manufacturing line, among other important projects. According to Dante, the defining moment of his co-op experience was his granule silo refurbishment project, which involved replacing eight silos, including floor plates and support beams.Dante explains the trust and opportunities his mentors provided were key to his success. "At GAF, I was given the chance to interact with contractors, and immerse myself in the plant, which accelerated my learning," he says.Co-Op Students Build Professional RelationshipsThrough "lunch and learn" sessions, leadership speaker series, meetings with senior leadership, and mentorship, co-op students build long-term professional relationships.Dante was given the chance to showcase the coordination and safety efforts involved in his granule silo project to the GAF executive leadership team in Parsippany, New Jersey.For Min, getting the right feedback to grow meant having the right relationships. He notes the mentorship from his manager Alex Smith and engineering manager Mike Kloda was key to his progression. As advice to future co-op participants, he explains that "everyone is here to help... but it's up to you to drive that forward."Meanwhile, the autonomy and leadership opportunities program leaders gave Michael allowed him to grow technically and professionally. "I was often the go-to person for projects, managing contractors and ensuring everything was on track," he says.Joining an Industry Filled with OpportunityThe GAF co-op program helped Min, Michael, and Dante start and solidify their careers in manufacturing engineering. Following their experience, each student was excited and motivated by the autonomy, responsibility, and growth opportunities they were given. In fact, Min has since accepted a full-time role as a project engineer at the GAF plant in Baltimore. His expected start date is July 7, 2025.GAF is committed to fostering diversity, equity, and inclusion throughout the organization. It believes a talented and diverse organization can drive innovation, growth, and transformation more effectively. To further bolster inclusivity, GAF offers academic and merit scholarships, partners with the Thurgood Marshall College Fund to recruit from the nation's most diverse talent at Historically Black Colleges and Universities and Predominantly Black Institutions, and reaches out to candidates at career fairs nationwide.Bright and motivated minds who want to explore manufacturing have plenty of opportunities. From shingles to solar to environmental impact, GAF offers many exciting career paths.Are you ready to do work that matters and be empowered to explore a leadership role? Discover the co-ops, internships, and job opportunities available at GAF.

Par les auteurs Annie Crawford

11 octobre 2024

Installation of ISO Board and TPO on a Roof
Science du bâtiment

Isolation des toitures : un investissement positif pour réduire l’empreinte carbone

Avez-vous déjà pensé à des produits de construction qui réduisent les émissions de dioxyde causées par votre bâtiment? When considered over their useful life, materials like insulation decrease total carbon emissions thanks to their performance benefits. Read on for an explanation of how this can work in your designs.What is Total Carbon?Total carbon captures the idea that the carbon impacts of buildings should be considered holistically across the building's entire life span and sometimes beyond. (In this context, "carbon" is shorthand for carbon dioxide (CO2) emissions.) Put simply, total carbon is calculated by adding a building's embodied carbon to its operational carbon.Total Carbon = Embodied Carbon + Operational CarbonWhat is Embodied Carbon?Embodied carbon is comprised of CO2 emissions from everything other than the operations phase of the building. This includes raw material supply, manufacturing, construction/installation, maintenance and repair, deconstruction/demolition, waste processing/disposal of building materials, and transport between each stage and the next. These embodied carbon phases are indicated by the gray CO2 clouds over the different sections of the life cycle in the image below.We often focus on "cradle-to-gate" embodied carbon because this is the simplest to calculate. "Cradle-to-gate" is the sum of carbon emissions from the energy consumed directly or indirectly to produce the construction materials used in a building. The "cradle to gate" approach neglects the remainder of the embodied carbon captured in the broader "cradle to grave" assessment, a more comprehensive view of a building's embodied carbon footprint.What is Operational Carbon?Operational carbon, on the other hand, is generated by energy used during a building's occupancy stage, by heating, cooling, and lighting systems; equipment and appliances; and other critical functions. This is the red CO2 cloud in the life-cycle graphic. It is larger than the gray CO2 clouds because, in most buildings, operational carbon is the largest contributor to total carbon.What is Carbon Dioxide Equivalent (CO2e)?Often, you will see the term CO2e used. According to the US Environmental Protection Agency (EPA), "CO2e is simply the combination of the pollutants that contribute to climate change adjusted using their global warming potential." In other words, it is a way to translate the effect of pollutants (e.g. methane, nitrous oxide) into the equivalent volume of CO2 that would have the same effect on the atmosphere.Today and the FutureToday, carbon from building operations (72 %) is a much larger challenge than that from construction materials' embodied carbon (28 %) (Architecture 2030, 2019). Projections into 2050 anticipate the operations/embodied carbon split will be closer to 50/50, but this hinges on building designs and renovations between now and 2050 making progress on improving building operations.Why Insulation?Insulation, and specifically continuous insulation on low-slope roofs, is especially relevant to the carbon discussion because, according to the Embodied Carbon 101: Envelope presentation by the Boston Society for Architecture: Insulation occupies the unique position at the intersection of embodied and operational carbon emissions for a building. Insulation is the only building material that directly offsets operational emissions. It can be said to pay back its embodied carbon debt with avoided emissions during the building's lifetime.A Thought Experiment on Reducing Total CarbonTo make progress on reducing the total carbon impact of buildings, it is best to start with the largest piece of today's pie, operational carbon. Within the range of choices made during building design and construction, not all selections have the same effect on operational carbon.When making decisions about carbon and energy reduction strategies, think about the problem as an "investment" rather than a "discretionary expense." Discretionary expenses are easier to reduce or eliminate by simply consuming less. In the example below, imagine you are flying to visit your client's building. Consider this a "discretionary expense." The input on the far left is a given number of kilograms of carbon dioxide equivalent (CO2e) generated for the flight, from the manufacturing of the airplane, to the fuel it burns, to its maintenance. The output is the flight itself, which creates CO2 emissions, but no durable good. In this case, the only CO2 reduction strategy you can make is to make fewer or shorter flights, perhaps by consolidating visits, employing a local designer of record, or visiting the building virtually whenever possible. Now consider the wallpaper you might specify for your client's building. It involves a discretionary expenditure of CO2e, in this case, used to produce a durable good. However, this durable good is a product without use-phase benefits. In other words, it cannot help to save energy during the operational phase of the building. It has other aesthetic and durability benefits, but no operational benefits to offset the CO2 emissions generated to create it. Your choices here are expanded over the previous example of an airplane flight. You can limit CO2 by choosing a product with a long useful life. You can also apply the three Rs: reduce the quantity of new product used, reuse existing material when possible, and recycle product scraps at installation and the rest at the end of its lifespan. In the final step in our thought experiment, consider the insulation in your client's building. As before, we must generate a certain amount of CO2e to create a durable good. In this case, it's one with use-phase benefits. Insulation can reduce operational energy by reducing heat flow through the building enclosure, reducing the need to burn fuel or use electricity to heat and cool the building. The good news is that, in addition to the other strategies considered for the flight and the wallpaper, here you can also maximize operational carbon savings to offset the initial embodied carbon input. And, unlike the discretionary nature of some flights and the often optional decision to use furnishings like wallpaper, heating and cooling are necessary for the functioning of almost all occupied buildings.Based on this example, you can consider building products with operational benefits, like insulation, as an "investment." It is appropriate to look at improving the building enclosure and understanding what the return on the investment is from a carbon perspective. As the comparison above demonstrates, if you have a limited supply of carbon to "invest", putting it into more roof insulation is a very smart move compared to "spending" it on a discretionary flight or on a product without use-phase carbon benefits, such as wallpaper.This means we should be careful not to measure products like insulation that save CO2e in the building use-phase savings only by their embodied carbon use, but by their total carbon profile. So, how do we calculate this?Putting It to the TestWe were curious to know just how much operational carbon roof insulation could save relative to the initial investment of embodied carbon required to include it in a building. To understand this, we modeled the US Department of Energy's (DOE) Standalone Retail Prototype Building located in Climate Zone 4A to comply with ASHRAE 90,1-2019 energy requirements. We took the insulation product's embodied energy and carbon data from the Polyisocyanurate Insulation Manufacturers Association's (PIMA) industry-wide environmental product declaration (EPD).To significantly reduce operational carbon, the largest carbon challenge facing buildings today, the returns on the investment of our building design strategies need to be consistent over time. This is where passive design strategies like building enclosure improvements really shine. They have much longer service lives than, for example, finish materials, leading to sustained returns.Specifically, we looked here at how our example building's roof insulation impacted both embodied and operational carbon and energy use. To do this, we calculated the cumulative carbon savings over the 75-year life of our model building. In our example, we assumed R-30 insulation installed at the outset, increased every 20 years by R-10, when the roof membrane is periodically replaced.In our analysis, the embodied CO2e associated with installing R-30 (shown by the brown curve in years -1 to 1), the embodied carbon of the additional R-10 of insulation added every 20 years (too small to show up in the graph), and the embodied carbon represented by end-of-life disposal (also too small to show up) are all taken into account. About five months after the building becomes operational, the embodied carbon investment of the roof insulation is dwarfed by the operational savings it provides. The initial and supplemental roof insulation ultimately saves a net of 705 metric tons of carbon over the life of the building.If you want to see more examples like the one above, check out PIMA's study, conducted by the consulting firm ICF. The research group looked at several DOE building prototypes across a range of climate zones, calculating how much carbon, energy, and money can be saved when roof insulation is upgraded from an existing baseline to current code compliance. Their results can be found here. Justin Koscher of PIMA also highlighted these savings, conveniently sorted by climate zone and building type, here.Support for Carbon Investment DecisionsSo how can you make sure you address both operational and embodied carbon when making "carbon investment" decisions? We've prepared a handy chart to help.First, when looking at lower-embodied-carbon substitutions for higher-embodied-carbon building materials or systems (moving from the upper-left red quadrant to the lower-left yellow quadrant in the chart), ensure that the alternatives you are considering have equivalent performance attributes in terms of resilience and longevity. If an alternative material or system has lower initial embodied carbon, but doesn't perform as well or last as long as the specified product, then it may not be a good carbon investment. Another consideration here is whether or not the embodied carbon of the alternative is released as emissions (i.e. as part of its raw material supply or manufacturing, or "cradle to gate" stages), or if it remains in the product throughout its useful life. In other words, can the alternative item be considered a carbon sink? If so, using it may be a good strategy.Next, determine if the alternative product or system can provide operational carbon savings, even if it has high embodied energy (upper-right yellow quadrant). If the alternative has positive operational carbon impacts over a long period, don't sacrifice operational carbon savings for the sake of avoiding an initial embodied product carbon investment when justified for strategic reasons.Last, if a product has high operational carbon savings and relatively low embodied carbon (lower-right green quadrant), include more of this product in your designs. The polyiso roof insulation in our example above fits into this category. You can utilize these carbon savings to offset the carbon use in other areas of the design, like aesthetic finishes, where the decision to use the product may be discretionary but desired.When designing buildings, we need to consider the whole picture, looking at building products' embodied carbon as a potential investment yielding improved operational and performance outcomes. Our design choices and product selection can have a significant impact on total carbon targets for the buildings we envision, build, and operate.Click these links to learn more about GAF's and Siplast's insulation solutions. Please also visit our design professional and architect resources page for guide specifications, details, innovative green building materials, continuing education, and expert guidance.We presented the findings in this blog in a presentation called "Carbon and Energy Impacts of Roof Insulation: The Whole[-Life] Story" given at the BEST6 Conference on March 19, 2024 in Austin, Texas.References:Architecture 2030. (2019). New Buildings: Embodied Carbon. https://web.archive.org/web/20190801031738/https://architecture2030.org/new-buildings-embodied/ Carbon Leadership Forum. (2023, April 2). 1 - Embodied Carbon 101. https://carbonleadershipforum.org/embodied-carbon-101/

By Authors Elizabeth Grant

Le 18 septembre 2024

Ne manquez pas une autre publication Roof Views de GAF!

Subscribe now