Building to Last With Asphalt-Based Roofing

The property owner of this building opted for a BUR/modified-bitumen hybrid system with reflective white coating. Photos: Johns Manville

The advantages of a built-up roofing (BUR), modified bitumen, or hybrid roofing assembly include long life, a variety of maintenance options, and outstanding puncture resistance. This durability means property owners will spend less time worrying about fixing leaking roofs and the associated hassles — lost productivity, disruption in operations, slips and falls, repair bills, and other liabilities.

Recommending clients install a roof system that gives them the best chance of eliminating unproductive distractions is a good business decision for design/construction professionals. A more durable roof will enable property owners to focus on making profits instead of dealing with the aftermath of a roof leak.

“I have no problem endorsing asphalt-based roofing,” says Luther Mock, RRC, FRCI and founder of building envelope consultants Foursquare Solutions Inc. “The redundancy created by multiple plies of roofing is really what sets systems like BUR and modified bitumen apart.”

One can argue BUR’s closest cousin — the modified bitumen (mod bit) assembly — is actually a built-up roof made on a manufacturing line. The reality is the plies of a BUR create a redundancy that can help mitigate any potential oversights in rooftop workmanship.

BUR systems are offered in a variety of attractive and reflective options with a proven track record of performance. Photos: Johns Manville

“I’ve replaced BURs for clients I worked with 30 years ago,” says Mock. “We recently replaced [a BUR] specified in the early 1980s. And the only reason was because some of the tectum deck panels had fallen out of the assembly. Meanwhile, the roof was still performing well after 30 years.”

According to the Quality Commercial Asphalt Roofing Council of the Asphalt Roofing Manufacturers Association (ARMA), one of the main drivers of the demand for BUR systems is the desire of building owners for long life cycles for their roofs.

“A solid core of building owners and roofing professionals in North America continue to advocate asphalt-based roofing systems because of their long lives,” says Reed Hitchcock, ARMA’s executive director.

Benefits of Asphalt-Based Roofing

Over the years, asphalt-based roofing assemblies have earned a reputation for reliability with building owners, roofing consultants, architects, engineers, and commercial roofing contractors. The original price tag tends to be greater than other low-slope roofing options, but these assemblies offer competitive life-cycle costs. BUR enjoys a track record spanning more than 150 years; it provides a thick, durable roof covering and can be used in a broad range of building waterproofing applications.

An aerial view of a reflective roof membrane. Photos: Johns Manville

Available as part of fire-, wind-, and/or hail-rated systems, BUR and modified bitumen assemblies offer proven waterproofing capabilities, high tensile strength, long-term warranties, and a wide choice of top surfacings (including ‘cool’ options). Their components include the deck, vapor retarder, insulation, membrane, flashings, and surfacing material. The roofing membrane can be made up of a variety of components, including up to four high-strength roofing felts, modified bitumen membranes (hybrid systems) and standard or modified asphalt. Hot-applied asphalt typically serves as the waterproofing agent and adhesive for the system.

The roofing membrane is protected from the elements by a surfacing layer — either a cap sheet, gravel embedded in bitumen, or a coating material. Surfacings can also enhance the roofing system’s fire performance and reflectivity ratings.

Another surfacing option is gravel, commonly used in Canadian applications where the existing roof structure can handle the extra weight. There are also several smooth-surface coating options, the most popular of which are aluminum or clay emulsion products offering greater reflectivity than a smooth, black, non-gravel-surfaced roof. These reflective roof coating options are typically used in warmer regions when required by code. Reflective white roof coatings are also becoming more popular.

Cold-Process BUR

Cold application of BUR has provided an alternative to traditional hot-applied systems for more than 48 years. The term ‘cold-applied’ means the BUR roofing system is assembled using multiple plies of reinforcement applied with a liquid adhesive instead of hot asphalt. These cold adhesives are used between reinforced base/ply sheets to provide a weatherproof membrane.

The owner of this shopping mall chose BUR primarily due to its redundancy. Multiple plies of roofing can provide extra insurance against water intrusion. Photos: Johns Manville

In BUR cold-process roof systems, manufacturers typically require that only fully coated, non-porous felts (such as standard base sheets) are used as base and ply sheets. Generally, an aggregate surfacing or a coating is then applied over the completed membrane to provide surface protection and a fire rating for the roof system.

“In the re-roofing market, we’re definitely seeing more cold-applied systems being specified, particularly with modified bitumen,” says Mock. “It’s a natural alternative when a building may be occupied during the reroofing process and hot asphalt is not an option.”

Adhesives can be manually applied with a squeegee, brush, or spray application equipment. When numerous roof penetrations or rooftop access become issues, manual application of adhesives is usually the best option. Proper coverage rates are vital to a successful, long-term, cold-applied roof system. Both spray and manual application methods require the proper amount of adhesive material be installed. If too little adhesive is applied, there is a potential for an improper bond to be formed between the felts. If too much is applied, then the potential for longer setup times and membrane slippage is increased. Additionally, ambient temperatures must be 40 degrees Fahrenheit (5°C) and rising before installation. This limits, but does not preclude, use of cold-process BUR in much of the northern United States and Canada.

“I’m also comfortable specifying BUR, because I’m confident I will have a seasoned contractor on the job,” says Mock. “The commitment in terms of skilled labor and equipment is simply too great for these contractors to be first-timers.”

Flashings are another critical component of every roofing system, particularly in cold-weather applications. Four-ply BURs use modified bitumen flashings almost exclusively. These membranes are predominantly styrene butadiene styrene (SBS)-modified and offer greater elongation in frigid climates where it counts most — at the interface of the roof system with other building components.

Use of a modified-bitumen base ply is one way of handling general flashing requirements, although modified bitumen cap sheets are more common.

BUR Repair and Maintenance

Like all roof systems to some extent, the life expectancy of a BUR system depends on the property owner’s commitment to routine maintenance. All roof systems can benefit from an owner willing to undertake a proactive management plan. BUR installed over an insulation package lends itself well to non-destructive testing in the future (e.g., infrared) as a means to maximize service life.

“Asphalt roofing systems have the potential for a very long life, and preventive maintenance is the key to realizing that potential,” says Hitchcock.

Non-gravel BUR surfacing options include aggregate, a mineral surface cap sheet, or a smooth, surface-coated membrane. Photos: Johns Manville

The goal is for problem areas to be detected and fixed before they develop into leaks. Inspections can reveal potentially troublesome situations, such as a loss of gravel surfacing, which could lead to felt erosion or brittleness. Less commonly, punctures and cuts to the membrane can occur, so it is wise to remove sharp objects and debris from the roof. Clogged drains or poorly sealed flashings also present problems that are repaired easily. The effects of chemical exhausts on roofing materials should also be monitored.

Preventive maintenance actions can help catch problems before they damage larger areas of the roof system. Inspections should be performed not only on aging roofs, but also on newly-installed roofs to guard against errors in installation, design, or specifications.

BUR and modified bitumen also have a long history of proven performance in the northern United States and Canada, where snow and ice buildup are common. Perhaps more than any other roof membrane, the BUR system shrugs off minor abuse.

BUR has proven to be a low-maintenance roofing system, and it can also be effectively repaired when needed. This means property owners can usually get more life out of a BUR. The ability to enhance the performance of existing BUR membranes with coatings, mod bit cap sheets, or flood coats of asphalt explain the long service lives of these systems in demanding applications.

“Property owners rarely have to replace a four-ply BUR until it is absolutely, positively worn out,” says one roofing contractor who asked to remain anonymous. “Based on experience, these asphalt-based systems ‘hang in there’ longer than less-robust roof options.”

When BUR Is Not the Best Option

There is no roofing product solution that will fit every building specification, and that certainly holds true for BUR. Probably more than any other roofing system (except spray polyurethane foam), the built-up roofing application is more of a skill than a science. As alternative systems have been introduced into the market, the job of finding experienced BUR contractors has become more difficult. This is especially true for the hot mopping of multi-ply BUR systems.

BURs are labor intensive and their installed cost will fluctuate with crude oil prices. However, as oil prices have continued to fall, BUR manufacturers have enjoyed the lowest asphalt pricing since the 2008-09 recession. (The price of oil peaked at about $117 a barrel in September 2012 and is $50 a barrel at this writing.) Typically BUR manufacturers will pass on a portion of these savings to their customers.

BUR has always held up well in life-cycle cost analyses. However, if a roof is not expected to last 20 years or more, it usually does not make sense to specify a premium four-ply BUR.

On larger projects, gravel-surfaced BURs are typically not practical from a cost standpoint unless a source of gravel is available locally. Projects where roof access is difficult often present challenges when roofing kettles are used. And despite the preponderance of low-fuming asphalts and kettles, re-roofing occupied buildings is often unacceptable to neighbors and/or the property owner.

Built-up roofing systems have sufficient strength to resist normal expansion and contraction forces that are exerted on a roof; however, they typically have a low ability to accommodate excessive building or substrate movement. Rephrased, if the roof must be used to “hold the walls” together or if the use of “loose-laid insulation” has a benefit, then a traditional three- or four-ply built-up roofing system is not a good choice.

A built-up roof typically provides high tensile strength with low elongation. Guidelines about where expansion joints should be installed in the roofing system should not be ignored by the designer. These guidelines include installing expansion joints where the deck changes direction, approximately every 200 feet (61 meters), although many consider that this dimension can be expanded for single-ply roofing membranes; where there is a change in deck material; and, anywhere there is a structural expansion joint, etc. Based on these requirements, on some projects it simply isn’t practical to use a BUR.

BUR materials must be kept dry before and during installation to prevent blistering in the roof system. Proper storage is the key: Do not overstock the roof; use breathable tarps to cover material on the roof; store material on pallets to minimize the possibility of material sitting in water; and store rolls on-end to prevent crushing. In general, polymeric single-ply membranes like TPO (thermoplastic polyolefin) are less susceptible to storage issues.

Many roof consultants and product manufacturers clearly state that there should be no phased construction of a built-up roof. If phasing is required, then a BUR should not be specified. This is a clean and simple rule to understand; if the roof being constructed is a four-ply BUR, then only as much insulation should be installed as can be covered the same day with all four of the plies in the built-up roofing membrane. Phased construction of a built-up roof greatly increases the potential for blistering of the membrane and does not allow for the total number of plies to be installed in a shingled fashion. Phased application contains other perils, such as roofing over a small amount of overnight precipitation or dew that, even with the best of intentions, can cause harm.

As stated above, costlier modified bitumen materials should be specified for flashings and to strip in metal. Stripping in two plies of felt will most likely result in splitting at the joints in a gravel stop because the two-ply application cannot accommodate the movement in the edge metal. On new or existing buildings where significant expansion/contraction is expected, a TPO, PVC or EPDM roof membrane can save the property owners money and eliminate premature roof failure due to roof splitting.

Conclusion

Manufacturers across North America are making asphalt roofing systems like BUR better and more versatile for architects, builders, contractors, roofing consultants, and building owner/managers. Thanks especially to the addition of polymers that add stretch and strength, architects can now specify a commercial, low-slope roof as part of a multi-ply BUR system any way they want it — hot, cold, torch, or self-adhered (hybrid BUR) — to meet the individual low-slope roofing project’s needs.

Most importantly, asphalt-based roofing products offer exceptional life-cycle cost performance. They have proven to be reliable, easy to maintain, and are trusted to perform exceptionally well in extreme weather conditions.

Hyload Adds to Product Portfolio

Hyload Inc., manufacturer and supplier of roofing and waterproofing solutions, announced the addition of a white, scrim re-enforced PVC membrane, as well as fleece-backed PVC membrane, to its product offering. Hyload is also offering three grades of modified bitumen roof membranes: fully adhered, torch grade, and an APP membrane.

Hyload’s current product offering includes through-wall flashing, membrane roofing, waterproofing and green roof systems. According to Dave Afanador, Business Development Manager at Hyload, “The additions round out our hugely successful offering of highly durable KEE membrane with other chemistries to assist in specifying roof membranes that are specific to the needs and price points of all of our current and future customers.”

For more information, visit www.Hyload.com.

New Construction Project Tests Contractor’s Mettle

Photos: Lynn Cromer Photography, Ferris, Texas

Photos: Lynn Cromer Photography, Ferris, Texas

Independence High School in Frisco, Texas, was conceived as an impressive new construction project on a tight schedule. The standing seam metal roof of the building was a key component in the architectural planning, as it was designed to provide aesthetic appeal for the massive structure while minimizing the view of mechanical equipment for passers-by on the ground.

The roof also was comprised of several low-slope sections, which were covered with a modified bitumen system. Both the metal and modified systems contributed to the building’s energy efficiency, helping the project achieve LEED Silver status.

The roof systems were installed by the Duncanville, Texas, branch of Progressive Roofing Services. Randy Dickhaut, the company’s general manager, indicated the project was completed in approximately one year—an ambitious schedule for a job of this size. “It was a challenging new construction job,” he says. “There were a lot of logistics involved, but in general, the job went very well.

A Tale of Two Roofs

The first goal of the project was drying in the metal decking. A two-ply, hot–mopped modified bitumen system manufactured by Johns Manville was installed on 24 decks totaling approximately 195,000 square feet of low-slope roof area. The system was applied over two layers of 2 1/2-inch polyiso insulation and 1/2-inch JM Securock cover board. The system was topped with an Energy-Star rated cap sheet, DynaGlas FR CR.

Photos: Lynn Cromer Photography, Ferris, Texas

Photos: Lynn Cromer Photography, Ferris, Texas

In the nine sections where the 88,000 square feet of metal roofing was installed, two layers of 2 1/2-inch polyiso insulation were attached, along with plywood decking and self-adhering TAMKO TW Tile and Metal underlayment. The standing seam metal roof system was manufactured by McElroy Metal, and the company provided the manpower and equipment to roll form the panels on the job site. Roof panels were the company’s 22-gauge Maxima 216 panels in Weathered Galvalume. These panels were complemented by 24-gauge Flush panels on walls and soffits.

The roll former was mounted on a scissor-lift truck. The eaves of the building were approximately 36 feet off of the ground, so a sacrificial panel was used to create a bridging effect to help guide panels to the roof. “Basically, the roll former went right along with us,” Dickhaut recalls. “We would pull 30 or 40 squares of panels, then drop the machine and move to the next spot. We were able to roll the panels right off the machine and lay them in almost the exact spot they would be installed.”

Photos: Lynn Cromer Photography, Ferris, Texas

The length of some of the panels posed a challenge, and as many as 12 crew members were needed to guide them into place for installation. In the steep-slope sections, crew members had to be tied off 100 percent of the time, so retractable lanyards were used to help keep safety lines out of the way.

The roof was mechanically seamed using a self-propelled industrial roof seamer manufactured by D.I. Roof Seamers. “We call it walking the dog,” notes Dickhaut. “One man can operate the equipment, and he just walks it every inch of every seam.”

The metal roof was designed to hide the mechanical equipment for the building, and Progressive Roofing completed work on two deep mechanical wells before the HVAC equipment was installed. “In the wells, we used McElroy’s Flush panels for the vertical surfaces and transitioned to the metal roofing,” notes Dickhaut. “In the bottom of the mechanical wells, we installed the Johns Manville modified roof and flashed the curbs.”

Rising to the Challenge

Dickhaut points to a few challenges on the job, including the length of the panels and the weather. “Overall, the job went really well,” he says. “The architects did a great job on the design, and McElroy has really good details. It was a pretty straightforward process. There was a lot of wind and rain we had to cope with. When you have a 100-foot panel that you can’t kink or scratch, it can get kind of tricky. You just have to be very careful.”

Photos: Lynn Cromer Photography, Ferris, Texas

Photos: Lynn Cromer Photography, Ferris, Texas

The Texas weather made the schedule unpredictable. “We were on that job over a year, so we caught all four seasons,” he says. “Weather had a huge impact. We dealt with extreme heat, humidity, snow, ice, mud, monsoon-type rains. Texas throws anything and everything at you.”

Whatever the conditions, Progressive Roofing was ready. “We show up locked and loaded,” Dickhaut says. “We attack it. We have seasoned veteran roofers that lead the pack. On that particular project, we had an architect, roofing consultants, an owner’s rep, and a general contractor. We would also bring in the McElroy and JM reps periodically for consultation. It’s really a team effort.”

TEAM

Architect: Corgan Associates Inc., Dallas
General Contractor: Lee Lewis Construction Inc., Dallas
Roofing Contractor: Progressive Roofing Services Inc., Duncanville, Texas

Kemper System Features Cost-Effective ‘Cool Roof’ Solutions

Kemper System America Inc. now offers two cost-effective ‘cool roof’ solutions for prolonging the life of metal, BUR, modified bitumen and aged single-ply roof systems.

Roof Guardian RG-170 is an elastomer-based coating system ideal for extending the life of many types of roofing assemblies. Formulated using a 100 percent acrylic polymer base for enhanced adhesion and durability, the coating features a high Solar Reflectance Index (SRI) rating of 109 and is Class A fire rated. Roof Guardian RG-180 is a fiber-reinforced elastomeric coating with an acrylic polymer base, ideal for metal, concrete, single ply, modified bitumen, and granular cap sheets. It offers an SRI rating of 108.

“Kemper System has been at the vanguard of liquid-applied roof waterproofing solutions for decades. These two new white Roof Guardian coating systems offer a quick and cost-effective approach for transforming many kinds of existing low-slope roofs into a cool roof that can help building owners cut cooling costs,” says Jim Arnold, Director of Product Development for Kemper System.

Part of the company’s Roof Guardian Technologies line, the roof coatings can be quickly applied with a commercial-grade sprayer or roller. The highly reflective bright white finish lowers the surface temperature of the substrate to reduce thermal transfer into the structure. This high solar reflectance helps lower indoor temperatures to reduce building cooling requirements.

Formulated to resist cracking and peeling, both products provide excellent waterproofing and long-term mildew resistance. Both solutions are Energy Star and Cool Roof rated.

“For more than 60 years, Kemper System has been a global industry leader in cold liquid- applied, reinforced roofing and waterproofing, having invented the technology and holding the first patents,” says Arnold. “Today the company offers a full range of building envelope solutions to protect against weather, preserve the integrity of surfaces, and enhance the comfort and value of buildings.”

This portfolio encompasses Wall Guardian fibered acrylic air barrier, Roof Guardian Technologies elastomer-based roof coatings, and HeatBloc-ULTRA radiant heat barrier. Other high-value brands include COLEAN traffic coating systems, and the company flagship for exterior and interior waterproofing, Kemperol reinforced membrane systems.

LEARN MORE

Visit: Kempersystem.net
Call: (800) 541-5455
Email: inquiry@kempersystem.net

ARMA Completes EPDs for Five Types of Asphalt Roofing

The Asphalt Roofing Manufacturers Association (ARMA) has completed a multi-year effort to develop Environmental Product Declarations (EPDs) for asphalt roofing systems. These five new documents provide information that building and construction professionals can use both to support environmental aspects of roof systems as part of sustainable building projects and to better understand their impact over time. EPDs are now available for asphalt shingle roofing systems, SBS and APP modified bitumen systems, and built-up roofing systems. 

When architects and specifiers embark on new green building initiatives, they need to validate the environmental aspects of the building materials they use. EPDs are used to provide this information and to support the credibility of environmental claims.  ARMA worked with thinkstep, a sustainability consulting company, and with UL Environment to validate the EPDs.  These comprehensive documents outline the environmental attributes associated with the manufacturing of various asphalt-related roofing materials. 
ARMA’s development of these five EPDs reflects the continued use and advancement of asphalt roofing materials. In some cases, these documents are needed to fulfill requirements for green building rating systems and initiatives such as Leadership in Energy and Environmental Design (LEED), Green Globes, and the International Green Construction Code (IgCC).

“As the worldwide building and construction community continues to expand the focus on creating environmentally responsible and resource-efficient building projects, asphalt roofing has a critical role to play,” said Reed Hitchcock, ARMA’s executive vice president. “ARMA is committed to supporting sustainable building initiatives, and we are proud to provide the industry with this important environmental information.”

“These EPDs will help architects and engineers make sustainable choices in roof design,” said Amy Ferryman, chair of ARMA’s Sustainability Task Force. “Our work to develop these resources helps ensure that the asphalt roofing industry can fully participate in increasingly important green building practices.”
The five EPDs from ARMA are now publically available and can be accessed on ARMA’s website.

Roofing Torch Program Reduces Fire Hazards During Modified Bitumen Application

CERTA offers a certification program in which authorized trainers deliver behavior-based training to roofing workers who install polymer modified bitumen roof systems.

CERTA offers a certification program in which authorized trainers deliver behavior-based training to roofing workers who install polymer modified bitumen roof systems.

The latest market survey conducted by the National Roofing Contractors Association (NRCA) shows the use of polymer modified bitumen as a percentage of all new roof systems, installed both in new construction and re-roofing projects, comprises about 10 percent of the total low-slope market, according to members responding. The significance of that share of the market for polymer-modified bitumen also highlights the importance of proper training in the use of roofing torches, the most common method for installation of such systems.

Background

In 1986, the Midwest Roofing Contractors Association (MRCA), in conjunction with industry organizations, the Asphalt Roofing Manufacturers Association, and the United Union of Roofers, Waterproofers and Allied Workers, developed a curriculum to train roofing workers in the safe application of torch-applied roof systems. This program was named the Certified Roofing Torch Applicator, or CERTA, program.

In 2003, insurance industry representatives approached NRCA to address concerns about an increase of losses and incidents involving torching activities conducted by roofing workers. One prominent insurer experienced over $7 million in roofing torch-related claims in 2002 spread over more than 30 separate occurrences. The need for enhanced work practices and focused safety training to address torching activities became apparent, and NRCA arranged with MRCA to adopt and revise the nature of and deliverables offered by the CERTA program.

CERTA now offers a unique, comprehensive certification program in which authorized trainers deliver effective behavior-based training to roofing workers who install polymer modified bitumen roof systems. CERTA-authorized trainers undergo a rigorous full-day training session that includes classroom and hands-on instruction in propane safety, hazards related to torch use, proper techniques for safe installation of polymer modified bitumen, and development of training skills. Individuals who successfully complete all aspects of the program then are authorized to deliver training, under the CERTA protocol, to workers who qualify as certified roofing torch applicators.

MRCA continues to work with NRCA to make sure the program is up-to-date and uses the most effective procedures to develop authorized trainers and enhance the curriculum. Since its inception, roofing contractors who have trained their workers under CERTA generally have experienced fewer torch-related fires, injuries and property damage. Insurance industry claims also are a testament to the CERTA program success—the insurer that experienced over 30 torch-related claims in 2002 now can count such average yearly claims on one hand with a significantly reduced average yearly dollar loss.

Safety Specifics

Trainees in a CERTA class spend a great deal of time on some specific aspects of the use of roofing torches to install a polymer modified bitumen roof system. Those specifics have a direct correlation to keeping workers and others safe, and minimizing the likelihood of property damage. First, the CERTA curriculum focuses on the inherent danger of roofing torches and discusses assessing job hazards and establishing controls for torching operations. Details cover the proper personal protective equipment to minimize or eliminate exposure to burns and the critical need to handle propane properly and make sure equipment is in good condition.

Pre-job planning enforces the significance of determining the hazards unique to the particular worksite and developing the necessary controls to address those hazards. In addition to general working conditions and weather issues that may influence job site safety, specific hazards such as the presence of a combustible roof deck, roof penetrations, concealed attic areas and combustible flashing substrates are addressed and suitable controls are suggested and discussed. Also, attendees get comprehensive information on the types and ratings of fire extinguishers and how they are used most effectively along with the minimum CERTA requirements for appropriate fire extinguishers that must be on a roof. In fact, CERTA requires a fire extinguisher capacity far exceeding OSHA’s fire protection requirements during torch operations— two 4A60BC-rated fire extinguishers within 10 feet of torching activity.

Another important fire prevention protocol is the use of a fire watch system. The intent of the fire watch is that a dedicated individual is charged with inspecting the work area after the last torch, or other heat generating tool, is extinguished. Ordinarily, this is accomplished visually, but it can also be done more scientifically with the use of temperature sensing infrared thermometer. These are inexpensive tools that read the temperature of an area that the tool is pointed at and display the reading in degrees on the screen. The fire watch individual would shoot various specific locations where hot work was done—for example, at roof penetrations, flashings or field areas—noting the temperature for each spot. This procedure would be followed for the same spots a short time later, and if the temperature had increased, the possibility that a fire under the roof surface could be a source of the increased heat being generated would require further steps to determine the nature of the heat increase and the proper action to take.

Historically, many industries and building owners have required a 30-minute fire watch be maintained after the last torch or other tool has been extinguished. Under the CERTA protocol, a two-hour fire watch is demanded of a CERTA roofing torch applicator. The fire watch must be maintained not just at the end of the day but at other break times, such as lunch, so that fires do not start when workers may be away from the work area or inattentive during break times.

Another key element of training for the CERTA torch applicator involves installation techniques that are intended to reduce the likelihood of a fire being started. The techniques include specified thermal barriers to protect combustible roof decks and substrate protection for flashing installations, along with an alternative torching technique that minimizes the use of direct torching.

Certa Works

Installation of polymer-modified bitumen roof systems using propane roofing torches requires adherence to a number of safety procedures and an awareness of the hazards that workers may encounter. The CERTA program has a proven track record of enhancing the safe practices of roofing workers who install these systems and the roofing industry, building owners and the general public are all safer because of its development and use.

Photo: NRCA

Prevent Roof Fires During Torch-Down Projects

Torch-Down Safety While driving to work recently, I heard a news story on the radio: An unlicensed roofer was charged with causing a fire at a local apartment complex. When I arrived at the office, I Googled “fires caused by roofers.” The results included stories from across the nation:

  • Roofing crew blamed for a Chicago strip-mall fire.
  • Roofer’s torch likely cause of huge Arizona construction-site blaze.
  • Roofer’s blowtorch sparks a six-alarm fire in Hamilton Township, N.J.
  • Obviously, using an open-flame torch to install torch-down roofing systems can pose a fire risk. Torch-down roofing is a type of roofing that consists of layers of modified bitumen adhered to layers of fiberglass with a flame torch. Torch-down roofing is used only for flat or low-slope roofs. This process is popular with many contractors, mainly because of its ease of installation and its adaptability. With this system, the modified bitumen can bond tightly to metal flashings while the rubbery additives in the asphalt allow the roofing to expand and contract when other roofing systems may crack. In addition, roofers like torch-down roofing because it is easy to apply. Unfortunately, it can also be dangerous!

    It is easy to make a mistake with the torch that could result in disaster. Consider roofers that are torching down a roof and accidentally overheat something in the attic—insulation, for instance. They end their work for the day, not noticing the smoke coming out of soffit vents. Before long, that smoldering material in the attic heats up and starts a fire that quickly spreads throughout the dry, hot attic and, often, to the rest of the structure. 

    Regulations and Best Practices

    OSHA has developed standards that can help prevent these types of fires. Here are some of OSHA’s fire-protection and -prevention rules from the construction and general industry standards:

  • A fire extinguisher must be immediately accessible for all torch-down operations.
  • A fire extinguisher is needed within 50 feet of anywhere where more than 5 gallons of flammable or combustible liquids or 5 pounds of flammable gas are being used on the job site.
  • No one on a job site can be more than 100 feet from a fire extinguisher at all times.
  • There must be at least one fire extinguisher for 3,000 square feet of work area.
  • All flammable or combustible debris must be located well away from flammable liquids or gases.
  • Combustible scrap and debris must be removed regularly during the course of a job.
  • Piles of scrap and debris must be kept at least 10 feet from any building.
  • A fire watch person should be posted to immediately address any possible smolders or flare-ups.
  • The fire watch person should remain on post for 30 minutes after the torch-down job is finished for the day.
  • While the actions spelled out in these construction regulations are mandatory, roofing professionals should be aware that these are minimum requirements. The National Roofing Contractors Association (NRCA) and the Midwest Roofing Contractors Association (MRCA) have developed a roofing torch applicator certification program designed to reduce fire hazards during torch application of modified bitumen products. According to Harry Dietz, Director of Risk Management for NRCA, the Certified Torch Applicator (CERTA) program teaches installers to minimize the exposure of combustible structural materials to the heat and flame of the roofing torch. The program also spells out a number of safe practices that go well beyond OSHA’s regulations in dealing with roofing torch use. Among other program elements, these include:

  • The requirement for two 4A60BC fire extinguishers during torch work (more than 10 times the firefighting capability required under the OSHA rules).
  • A two-hour fire watch performed after the last torch has been extinguished.
  • Following these guidelines for fire prevention can protect roofing professionals and the public. It can also save roofers money and time, as well as protect contractors from lawsuits and other legal charges. 

    “In 2002, a leading insurer of roofing contractors had over $7 million in torch related claims in 33 occurrences prior to requiring CERTA for its insureds,” said Dietz. “In 2015, that same insurance company reported only one torch-related claim with a loss of less than $10,000.”

    Visit this site to learn more about OSHA’s Safety and Health Regulations for Construction, Welding and Cutting, Fire Prevention. To learn more about the Certified Torch Applicator (CERTA) program, click here.

    Two Commercial Installations Are Honored with ARMA’s QARC Awards

    Advanced Roofing Inc. installed two new roofs at a luxury retired-living community in Palm Beach Gardens. These projects were Silver Award winners in ARMA’s 2016 QARC Awards.

    Advanced Roofing Inc. installed two new roofs at a luxury retired-living community in Palm Beach Gardens. These projects were Silver Award winners in ARMA’s 2016 QARC Awards.

    Commercial roofs are the workhorses of a building system. They endure wind, rain, hail and foot traffic while serving as an important line of defense between the outside world and a building’s occupants. If inhabitants never consider the roof over their heads, it means the roof system is doing its job well.

    The Washington, D.C.-based Asphalt Roofing Manufacturers Association (ARMA) showcases these hardworking but rarely celebrated systems in its annual Quality Asphalt Roofing Case- study (QARC) Awards program. Each year, the organization seeks the top asphalt roofing projects in North America that demonstrate durability and high performance, as well as beauty. The QARC awards honor a Gold, Silver and Bronze winning project that illustrates the benefits of asphalt roofing.

    The Silver Winner of ARMA’s 2016 QARC Awards is a prime example of what a commercial roofing system must stand up to while remaining water-resistant and durable. Advanced Roofing Inc. (ARI), which has service areas throughout much of Florida, was hired to install two new roofs at a luxury retired-living community in Palm Beach Gardens. These reroofs were completed in 2015 and were submitted to ARMA’s awards program.

    The two buildings in this community were originally built in the 1990s and were found to have numerous issues that demanded immediate attention when new management reviewed the property. The area’s hot climate requires many air-conditioning units on the roof that frequently have to be serviced. This aspect of a commercial roof can be overlooked by building owners but has a significant impact on its service life and performance. Because HVAC units and related equipment are heavy and may require frequent maintenance that brings extensive foot traffic, they can cause a roof system to deteriorate faster than normal. That was the case with the existing roofs in this living community.

    Toward the end of the roofs’ service lives, temporary fixes, like patching and coatings, were made. These regular repairs only increased the operational budget while the core issues remained unresolved. According to Jessica Kornahrens, project manager at ARI, “The existing roofing system was at risk of a failure that could potentially close the building and leave its elderly residents without a home.”

    ARI was hired by the new building owner and property manager to tear off the existing roofs of these two buildings and install an asphalt roofing system on each. Because of the significant durability required by the new roofs, the roofing contractor chose a high-performance three-ply modified bitumen asphalt roofing system.

    The two buildings in the retirement facility were still occupied during the reroof project, creating an additional challenge during installation, but the work came in on schedule and within budget.

    The two buildings in the retirement facility were still occupied during the reroof project, creating an additional challenge during installation, but the work came in on schedule and within budget.


    “We knew that this type of redundant, multi-layered system would protect these buildings long-term despite the high foot traffic and heavy equipment they have to stand up to while also meeting the project budget,” Kornahrens says. “This particular system also has a Miami-Dade Notice of Acceptance with testing and approvals for Florida’s high-velocity hurricane zone.”

    Between foot traffic and harsh weather, the contractors knew this asphalt roofing system was up to the task.

    Challenging Installation

    Before they could begin the project, ARI had to first stop the existing leaks in the first 45,900-square-foot building and the second 51,000-square-foot building, followed by a tear-off of the roof system down to the light- weight concrete. ARI fastened the modified anchor sheet with twin-lock fasteners directly into the lightweight insulated concrete deck and then torch applied an interply and fire-retardant granulated cap sheet.

    Photos: Smith Aerial Photography

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    Modified Bitumen Membranes Adhere to a Variety of Substrates

    SA-APP KoolCap and SA-APP KoolCap FR modified bitumen roofing membranes adhere to a variety of roofing substrates.

    SA-APP KoolCap and SA-APP KoolCap FR modified bitumen roofing membranes adhere to a variety of roofing substrates.

    Mule-Hide Products Co. has made available SA-APP KoolCap and SA-APP KoolCap FR modified bitumen roofing membranes, which adhere to a variety of roofing substrates. The products deliver the safety and ease of self-adhering application, long-term performance and durability, as well as the benefits of a cool roof. Complementing the membranes is the new SA-APP KoolCap Touch-Up Kit for treating lap areas, details and repairs. The granular-surfaced cap sheets are manufactured using a patented dual-compound technology in which a true APP polymer modified asphalt compound is applied to the top, weathering side and a proprietary adhesive formulation is applied to the bottom surface.

    An Oceanfront Elementary School Poses Tough Problems, but a Coated Aluminum Standing-seam Roof Passes the Test

    Elementary school students sometimes find themselves staring out the window, but few have a view to rival that of the students at Sullivan’s Island Elementary School in Sullivan’s Island, S.C. The school is located on oceanfront property, and when it was time for the original building to be rebuilt, the site posed numerous challenges.

    The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

    The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

    The original school had been built in the 1950s. It had been designed for 350 students and built on grade. The new school would have to be elevated to conform to modern building codes and service 500 students. The structure would not only have to withstand high winds, severe weather and a salt-air environment, but it also would have to fit into its surroundings. Many residents feared the larger building would look out of place in the cozy beach community. It was architect Jerry English’s job to figure out a way to make it work.

    English is a principal at Cummings & McCrady Architects, Charleston, S.C., the architect of record on the project. He worked with a talented team of construction professionals, including Ricky Simmons, general manager of Keating Roofing & Sheet Metal Co. Inc. in Charleston, to refine his vision and bring it to life. English and Simmons shared their insight on the project, and they both point to the building’s metal roof as a key element in the project’s success.

    CHALLENGING DESIGN

    Cummings & McCrady Architects handles a broad range of commercial, institutional, religious and historic work—new construction and renovation. The firm had done a lot of work with the Charleston County School District over the years, including a small library addition for the original Sullivan’s Island Elementary School after Hurricane Hugo passed through in 1989, and it was awarded the new construction project.

    The building’s foundation system had to meet strict regulations regarding resistance to storm surge. The building is elevated on concrete piers, which were topped with a 6-inch reinforced concrete slab. Metal framing was constructed above the slab. “With our building, we had to raise the underside of the structure almost 7 feet above the grade,” English recalls. “What we did is we built it a little bit higher than that so the underside could be left open and used for playground.”

    For English, coming up with a design that would reflect the character of the local community was the biggest challenge. To achieve that goal, he broke up the building into four sections and spread them across the site with the tallest sections in the center. “We have four linked segments that transition down on each end to the height of the adjacent residences,” he says.

    The roof was also designed to blend in with the neighboring homes, many of which feature metal roofs. “The idea of pitched roofs with overhangs became a strong unifying element,” English explains.

    English checked with several major metal roofing manufacturers to determine which products could withstand the harsh oceanfront environment and wind-uplift requirements. “Virtually every one of them would only warranty aluminum roofing,” he says. “The wind requirement and the resistance to the salt air were what drove us to a coated aluminum roof.”

    The majority of the panels were factory-made, but the manufacturer supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

    The majority of the panels were factory-made, but Petersen Aluminum supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

    The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide. Metal trusses give the roof system its shape. English tapped the resources of roof consultant ADC in Charleston and the metal roofing manufacturer to iron out all the details. English wanted to avoid any cross seams in the metal roofing, so he worked with Dave Landis, the manufacturer’s architectural/technical sales manager, to arrange for the longest panels to be formed onsite.

    The roof also includes two decks that serve as outdoor teaching areas. These sections were covered with a two-ply modified bitumen roof system and protected with a multi-colored elevated concrete paver system.

    Another standout feature is the school’s entry tower, which is topped by a freestanding hip roof featuring curved panels. This roof was constructed with panels that were 12-inches wide. “We found other examples on the island where the base of the roof flares a little bit as a traditional element, and with the closer seamed panels they were able to get those curves,” English says. “It’s a refinement that’s a little different than the rest of the roof, but it’s the proper scale and the fine detailing pulls it together and sets if off from the main roof forms that are behind it.”

    PHOTOS: Petersen Aluminum Corp.

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