Conductive Primer Designed for Electronic Testing of Conventional Roof Assemblies

Detec Systems has developed TruGround, a conductive primer which enables accurate electronic leak detection (ELD) testing on conventional roof membranes including black EPDM, TPO, PVC, modified bitumen, hot and cold fluid applied. According to the manufacturer, TruGround must be installed directly below the membrane per ASTM D7877. TruGround can be used for quality assurance testing on newly installed membranes and is chemically compatible with fully adhered, mechanically attached and torch-down membranes. Once applied, ELD testing can be performed for the life of the roof. Future breaches or seam voids can be quickly pinpointed, allowing repairs to be done immediately, preventing costly moisture damage from occurring.

For more information, visit www.detecsystems.com.

IRE and R&D

The conventional wisdom is that when the overall economy is strong, manufacturers feel more comfortable investing their resources in research and development of new products. I don’t have hard numbers to back that assertion up, but in my experience, at least anecdotally, it seems to be borne out. During the Great Recession years of the last decade, the number of new products coming to market seemed to decline. If the array of new products I saw at this year’s International Roofing Expo (IRE) in New Orleans is any indication, we could be in for a banner year.

The IRE makes it easy to keep tabs on new developments with its New Product Pavilion. The depth and breadth of offerings in that area was impressive, but I saw products being unveiled all over the show floor. Time will tell if they will turn out be a flash in the pan, a category-changing development, or something in between — but for the Roofing team, it was a very interesting show to cover, as there were a lot of excited responses when we asked, “What’s new?”

Innovative products on display included a pre-weathered fastener from Lakeside Construction Fasteners that matches aged Corten panels, so installation and repairs don’t leave bright silver dots on the rust-colored surface.

Carlisle showcased its Rapid Lock Technology, which uses a Velcro attachment system to secure the company’s EPDM and TPO membranes without using a bonding adhesive, doing away with temperature restrictions.

OMG Roofing Products unveiled its RhinoBond Hand Welder, which can be used to install the company’s induction welding fastening system in hard-to-reach areas, such as spaces below signs, pipes and rooftop equipment.

Georgia-Pacific showed off enhancements to DensDeck Prime that make the cover boards more resistant to water and increase their vertical pull strength.

Roof Sentry announced the launch of a solar-powered roof vent that provides moisture detection and data monitoring services. It can also remove moisture from low-slope roof systems.

On the residential side, new developments included GAF’s shingles with StainGuard Plus, which uses copper granules with time-release technology to fight algae growth.

Tie Down Engineering offered the Ergo Stripper, an ergonomically designed tool for removing shingles that improves leverage and eases strain on the back.

The Roof Umbrella rooftop canopy system is designed to be installed in less than 30 minutes on jobsites to prevent weather delays. It can be customized with the contractor’s logo.

These are just a few of the items that caught our eye at the IRE. We will be showcasing them in this issue and future issues of the magazine as part of our editorial mission to keep readers up to date on new products hitting the market. If you saw a new product you’d like us to be aware of, just email me at chris@roofingmagazine.com.

Reinforced EPDM Membrane Offers Tape-to-Tape Technology

JM EPDMJohns Manville unveils a new reinforced EPDM membrane sheet with tape-to-tape technology, JM EPDM R FIT. According to the manufacturer, the product is field tested and proven to speed up installation by as much as four times, leading to lower labor costs. The expense and time involved when using other membranes that require primer is also eliminated since no primer is needed, leading to lower installed costs. The initial bond between tape-to-tape membrane sheets has been measured to be up to 20 percent stronger compared to field-fabricated seams. The watertight seam is never exposed on the rooftop, so the risk of contamination during installation and post installation is minimal.

John Petruzzi, president of FPS Roofing, installed the new product and was impressed with how quickly the crew learned techniques to apply it. “We were sold when we saw for ourselves how fast the seam went together. We were hands-on with the product, the whole crew liked it, and I will continue to use it,” said Petruzzi.

JM EPDM R FIT enables a longer window of application time since the 10-foot-by-100-foot rolls are completely pre-taped. This means there is no waiting on primer to flash off to get to the next step. “Our field tests demonstrate that this product will go down up to four times faster than anything already on the market,” said John Quante, JM EPDM Product Manager, Roofing Systems. “The tape-to-tape creates a stronger initial bond, making the installation more robust from day one. This product evolution will allow roofers to bid more aggressively and no doubt architects and specifiers will see the benefits too.”

For more information, visit www.jm.com/roofing.

Silicone Coating Restores the Roof, Reduces Utility Costs at Mixed-Use Complex

At the Shoppes of Johnson’s Landing in Angier, North Carolina, ACC applied a high-solids silicone roof coating on the 20-year-old metal roof to seal penetrations, restore the roof, and provide a white reflective coating. Photos: All-County Contracting (ACC)

Glenn Wujcik, the owner of All-County Contracting (ACC), headquartered in Raleigh, North Carolina, has been fascinated with spray rigs since he and his brother first used one in 1979 to insulate a van with spray polyurethane foam (SPF). His company specializes in applying SPF and roof coatings on existing buildings. Lately, he’s found silicone roof coatings are making up an increasing share of his company’s workload.

“The coatings industry in general is booming right now,” Wujcik says. “A lot of the TPO and EPDM roofs are nearing the end of their service life, and instead of tearing them off, if you catch them in time, you can go over it with the silicone coating and get a new 10-year warranty. Silicones have a proven track record. When you put it on properly, it weathers really well. It has excellent elongation.”

Wujcik characterizes himself as a hands-on owner who strives to be on the site for every job. He believes there is an art as well as a science to operating a spray rig properly, and experience is crucial. “I love doing this,” he says. “I’ve been doing it for more than 30 years, my business partner’s been doing it more than 30 years, and our best sprayer has sprayed more than both of us combined. We know what we have to do, we know how long it’s going to take, and we have the right equipment. We are really good about the preparation and the application.”

Coatings and spray foam are excellent products, but only in the right situations, notes Wujcik. They should only be used on the proper substrates and applied in the right conditions. “In spraying, the most important thing is knowing when not to spray,” he says. “Right now, I’m working on a job, and for the last two days, there have been 10-20 mph winds, and I haven’t finished it yet. I told the owner, ‘I haven’t oversprayed anything yet, and I don’t want to.’ I’d rather do it right and not have any problems.”

Wujcik points to a recent project on a mixed-use building in Angier, North Carolina, to illustrate some of the benefits of a silicone roof coating. “It’s a U-shaped building with about 14,000 square feet of roof space,” Wujcik notes. “There’s a bakery, a restaurant, a pharmacy, and a doctor’s office, and there are a lot of penetrations on the roof.”

The penetrations were the site of multiple leaks. Wujcik decided to use a high-solids silicone coating, GE Enduris 3502, to prevent leaks and extend the life of the roof. The monolithic coating will seal the penetrations, and the white reflective surface will provide an additional benefit: reduced cooling bills in the summer. “Putting a white coating on it is going to reduce their energy load in the summer pretty substantially,” he says.

Applying the Coating

On this project, the first step was to pressure wash the existing roof. “That’s where most coating jobs fail — surface preparation,” Wujcik states. “Washing the roof properly is one of the most important steps.”

The high-solids silicone coating was applied to the existing standing seam metal roof. Care had to be taken to ensure all sides of the metal ribs were properly covered with the material. Photos: All-County Contracting (ACC)

The company uses 4,000 psi belt-drive power washers, so care has to be taken not to damage the roof or skylights, which are covered and marked for safety reasons. The company follows all OSHA regulations, which in most cases means setting up safety lines 6 feet from the edge, with stanchions 10 feet apart, to establish a safety perimeter.

“Safety is my number one thing,” Wujcik says, “I’ve been doing this a long time and I’ve never had a lost-time accident. I preach safety. That is absolutely the most important — and accidents are expensive.”

The next step is to apply the GE Seam Sealer at the penetrations. “When this roof was originally installed 20 years ago, they did it textbook perfect,” Wujcik notes. “Each 4-inch pipe coming though had at least 20 fasteners holding it down.”

However, over time, the rubber grommets on the fasteners can degrade, and expansion and contraction can take their toll. “We have really hot summers here, we’ve seen roofs where literally thousands of fasteners have backed out,” he says.

The seam sealer is typically applied with a brush. “Any horizontal seams, any termination bars, any penetration that goes through the roof that has a screw, we apply the seam sealer,” he says. “It goes on quite thick — at about 80 linear feet per gallon.”

After the seam sealer cures for one day, the coating is applied. Spraying flat roofs with EPDM, TPO, and PVC membranes is a fairly straightforward process, according to Wujcik. “You basically spray it just like you would spray paint a wall,” he says. “You overlap your spray pattern 50 percent. I’ve been doing it for so many years, and you get a feeling for how fast you can go.”

After the roof was power washed, the seam sealer as applied to the seams and penetrations. After it cured, two coats of the high-solids silicone product were sprayed on the roof. Photos: All-County Contracting (ACC)

A wet mil gauge is used to ensure the proper thickness. Wujcik notes the high-solids silicone formulation has very little shrinkage as it dries.  “As we’re spraying, we insert the gauge into the wet coating and it tells you how many mils you have sprayed down. In this case, we were applying to achieve 21 dry mils.”

The spray rig is set up on the ground and operated by one man, while the sprayer and the hose man are working on the roof. “It’s a minimum of a three-man crew per coating rig,” he notes. “You’re dealing with about 6,000-7,000 psi of pressure, so you need special hoses rated for at least 7,000 psi. You never want to kink them. If you busted a hose, by the time someone came down from the roof to the machine, you could pump out 20 gallons on the ground. That’s why you need a ground man.”

Flat roofs are sprayed perpendicular to the roof, but the standing seam metal roof on this project called for a different technique. “On metal roofs with high ridges, if you don’t angle your gun you’ll miss the sides of the ribs,” Wujcik points out. “You have to do it from one direction, working one way, and then turn around and do it from the other direction, working the other way. If you try to spray straight down on the roof, you’re going to miss the nooks and crannies in all of those ribs.”

The surface area of the ribs also has to be taken into account when calculating the amount of liquid that will be applied, notes Wujcik.

The final step in the process is to touch up the applications at the penetrations to ensure a clean look. On vertical surfaces including parapet walls, crews ensure the coating is applied to a uniform height. “On the last day, we take up brushes and rollers and cut in straight lines,” he says. “That really finishes the job. The detailing gives it that final touch.”

Open for Business

The active and open jobsite posed some challenges. “There were a lot of cars around the building, so we had to be very careful not to hit them with overspray,” Wujcik notes. “When you’re working on a plant, you might be able to move all of the cars to a different location, but at doctor’s offices and restaurants, you have traffic in and out of the parking lot all of the time. We can use car covers if there are a few cars there, but when they are in and out like that, it’s not practical, so you have to be very careful when you do the job.”

The job was completed in the winter, and bad weather resulted in some delays. “A job like this in the summertime would have been a weeklong project at most,” Wujcik notes. “This project took almost a month because we had an exceptionally cold winter with a lot of high winds. It took extra time, but that’s my philosophy: If it’s not the right conditions, I just won’t do it.”

The project qualified for a 10-year warranty, and when it expires ACC plans to be there to pressure wash and recoat the roof for another 10-year warranty.

“We inspect our jobs every year,” Wujcik says. He notes that annual roof inspections and routine maintenance are the simplest and most cost-effective ways to ensure the roof’s life span. Yet these steps are often neglected.

“It’s amazing that some of these multi-million-dollar companies don’t send their maintenance guys up on the roof for 10 minutes to check the drains,” he says. “If a roof has 2 inches of pine needles around the drain, the whole roof has to have 2 inches of water on it before it begins to drain. That puts tremendous, tremendous stress on a roof. Keeping your drains clear is really important.”

TEAM

Roofing Contractor: All-County Contracting (ACC), Raleigh, North Carolina

MATERIALS

Roof Coating: Enduris by GE 3502, GE Performance Coatings, www.GE.com/silicones
Seam Sealer: GE Seam Sealer, GE Performance Coatings

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.

Single-Ply Roofing Best Practices: Doing Everything Right the First Time.

Figure 1: Designing resilient roof systems is the best of practices. When developing details, we find it very helpful to draft out the roof system (for each different system), noting materials and installation methods. Photos: Hutchinson Design Group

Single-ply membranes have risen from being the “new guy” in the market in the early ’80s to become the roof cover of choice for most architects, consultants and contractors. Material issues have for the most part been resolved, and like no other time in recent history, the industry is realizing a period of relative calm in that regard. Whether EPDM, TPO or PVC, the ease of installation, the cleanliness of the installation (versus the use of hot or cold bitumen), the speed at which they can be installed, and the material costs all blend to make these materials a viable option for watertight roofing covers. But with this market share comes issues and concerns, some of which are hurting owners, giving forensic consultants such as myself too much business, enriching attorneys, and costing contractors and, at times, designers dearly.

Following are some of my thoughts on various issues that, in my opinion, are adversely affecting single-ply membrane roof systems. Paying attention to these issues will bring about best practices in single-ply applications.

Specifying the Roof by Warranty

OMG, can architects do any less? Don’t get me started. The proliferation of “canned” Master Specs which call for a generic 10-year or 20-year warranty and then state to install the product per manufacturer’s guidelines is disheartening. Do

Figure 2: Coordinating with the mechanical engineer in the detailing of the pipe penetrations is critical. Here you can see all the components of the curb, penetrations, roofing and waterproofing are noted. We recommend that the same detail be on the mechanical sheets so that at least an 18-inch curb is known to all. Photos: Hutchinson Design Group

designers realize that manufacturers’ specifications are a market-driven minimum? When architects leave out key details, they are simply relying on the roofing contractor to do what is right. This deserves another OMG. The minimum requirements for a warranty can be very low, and the exclusions on a warranty quite extensive. Additionally, a design that calls for products to be installed based on achieving a warranty may result in a roof system that does not meet the code. Owners are often oblivious to the warranty requirements, and all too often fail to ensure the standard of care until the service life is shortened or there is storm damage — sometimes damage the roof should have withstood if it were properly designed and detailed.

If one is not knowledgeable about roof system design, detailing and specification, then a qualified roof consultant with proven experience in single-ply membranes should be retained. Roof systems and their integration into the impinging building elements need to be designed, detailed and specified appropriately for the building’s intended use and roof function. By way of example, we at Hutchinson Design Group typically design roof systems for a 40- to 50-year service life (see Figure 1); the warranty at that point is nice, but almost immaterial. Typical specifications, which are project specific, cover all the system components and their installation. They are typically 30 pages long and call out robust and enhanced material installations.

More Than the Code

I recently had a conversation with a senior member of a very large and prominent architectural firm in the Chicago area and inquired about how they go about designing the roof systems. The first thing he said was, “We do what is required by code.”

Photo 1: The roof drain sump pans shown here were provided and installed by the plumbing contractor, not the steel deck installer. Having the roof drain level with the top of the roof deck allows for a proper integration of the roof drain and roof system.

What I heard was, “We give our clients the absolute poorest roof the code allows.” An OMG is allowed here again. Does it really need to be said again that the code is a minimum standard — as some would say, the worst you are allowed to design a building by law? Maybe you didn’t realize it, but you are allowed to design above the code. I know this will shock a few of you, but yes, it’s true. Add that extra anchor to prevent wood blocking from cupping. Add extra insulation screw fasteners to improve wind uplift resistance; if too few are used, you may meet the code, but your insulation will be susceptible to cupping. Add that extra bead of polyurethane adhesive. (If I specify 4 inches on center, then perhaps by mid-day, on a hot and humid day, I might get 6 inches on center — as opposed to specifying 6 inches or 8 inches on center, and getting 12 inches on center in spots.) Plan for construction tolerances such as an uneven decks and poorly constructed walls. Allow for foot traffic by other trades. These types of enhancements come from empirical experiences — otherwise known as getting your butt in the ringer. Architects need more time on the roof to observe what goes on.

It’s About Doing What is Right

Doing it right the first time isn’t all that difficult, and it’s certainly less stressful than dealing with the aftermath of doing so little. The cost of replacing the roof in the future could easily be more than double the original cost. Twenty years ago, I

Figure 3: Coordinating with the plumbing engineer, like coordinating with the mechanical engineer, is a requirement of best practices. In this drain detail, we can see the sump pan is called out correctly, and the roof drain, integration of the vapor barrier, extension ring, etc., are clearly defined. Photos: Hutchinson Design Group

chaired an international committee on sustainable low-slope roofing. At that time, the understanding of sustainability was nil, and I believe the committee’s Tenets of Sustainability, translated into 12 languages, helped set the stage for getting designers to understand that the essence of sustainability is long-term service life. That mantra seems to have been lost as a new generation of architects is at the helm. This is unfortunate, as it comes at a time when clients no longer ask for sustainable buildings. Why? Because they are now expected. The recent rash of violent and destructive storms — hurricanes, hail, intense rain, high winds and even wildfires — have resulted in calls for improvement. That improvement is called resiliency. If you have not heard of it, you are already behind. Where sustainability calls for a building to minimize the impact of the building (roof) on the environment, resiliency requires a building (roof) to minimize the impact of the environment on the building. This concept of resiliency requires designing a roof system to weather intense storms and to be easily repaired when damaged. (Think of Puerto Rico and consider how you would repair a roof with no power, limited access to materials, and manpower that might not be able to get to your site.)

Achieving resiliency requires the roof system designer to:

  1. Actually understand that roofs are systems and only as good as their weakest link. Think metal stud parapet and horizontal base anchor attachment; only forensic consultants and attorneys like to see screws into modified gypsum boards.
  2. Eliminate your old, out-of-date, incorrect details. Lead vent flashing and roof cement cannot be used with single-ply membrane.
  3. Design the roof system integration into associated barrier systems, such as where the roofing membrane (air/vapor retarder) meets the wall air barrier. You should be able to take a pencil and draw a line over the wall air barrier, up the wall and onto the roof without lifting it off the sheet. If you cannot, you need to redesign. Once you can, you need to consider constructability and who may get there first — the roofer or air barrier contractor. Then think material compatibility. Water-based air barrier systems don’t react well when hit with a solvent-based primer or adhesive.

    Photo 2: This roof drain is properly installed along with 6 inches of insulation and a cover board. The drain extension ring is 1/2 inch below the top of the cover board so that the water falls into the drain and is not held back by the clamping ring, resulting in ponding around the roof drain.

    Perhaps the roofing needs to be in place first, and then the air barrier brought over the top of the roofing material. This might require a stainless-steel transition piece for incompatible materials. Maybe this requires a self-adhering membrane over the top of the roof edge prior to the roofing work, as some membranes are rather rigid and do not bend well over 90-degree angles. You as the designer need to design this connectivity and detail it large and bold for all to see.

  4. Design the roof system’s integration into the impinging building elements, including:
  • Roof curbs for exhaust fans: Make sure they are insulated, of great enough height, and are not installed on wood blocking.
  • Rooftop unit (RTU) curbs: The height must allow for future re-roofing. Coordinate with the mechanical engineer regarding constructability – determine when the curb should be set and when the HVAC unit will be installed. Roof details should be on both the architectural and mechanical drawings and show the same curb, drawn to scale. Be sure the curb is insulated to the roof’s required R-value. Avoid using curb rails to support mechanical equipment. The flashing on the interior side of the rails may be inaccessible once the equipment is placed. Use a large curb where all four sides will remain accessible.
  • Piping penetrations: Detail mechanical piping penetrations through the roof and support of same, where insulation and waterproofed pipe curbs are needed (see Figure 2). If you are thinking pourable sealer pocket, stop reading and go sign up for RCI’s Basics of Roof Consulting course.
  • Roof curbs, RTU, pipe curbs and rails: Coordinate their location and show them on the roof plan to be assured that they are not inhibiting drainage.
  • Roof drains: Coordination with the plumbing engineer is essential. Sump pans should be installed by the plumbing contractor, not the steel deck installer (see Photo 1), and the location should be confirmed with the structural engineer. Be sure drains are located in the low point if the roof deck is structurally sloped — and if not, know how to design tapered insulation systems to move water up that slope. Do not hold drains off the deck to meet insulation thickness; use threaded extensions. Be sure any air/vapor barrier is integrated into the curb and that the insulation is sealed to the curb. I like to hold the drain flange a half-inch down below the insulation surface so that the clamping ring does not restrain water on the surface. Owners do not like to see a 3-foot black ring at the drain, where ponding water accumulates debris (see Figure 3 and Photo 2).
  1. Understand the roof’s intended use once the building is completed. Will the roof’s surface be used for anything besides weather protection? What about snow removal? Will there be excessive foot traffic? What about mechanical

    Photo 3: Gaps between the roof insulation and roof edges, curbs and penetrations are prevalent on most roofing projects and should be sealed with spray foam insulation as seen here. It will be trimmed flush once cured.

    equipment? Photovoltaic panels? Yes, we have designed roofs in which a forklift had to go between penthouses across the roof. Understanding how the roof will be used will help you immensely.

  2. Understand the construction process and how the roof might be used during construction. It is amazing how few architects know how a building is built and understand construction sequencing and the impact it can have on a roof. I firmly believe that architects think that after a lower roof is completed, that the masons, carpenters, glazers, sheet metal workers, welders, pipe fitters, and mechanical crews take time to fully protect the newly installed systems (often of minimal thickness and, here we go again, without a cover board — OMG) before working on them. I think not. Had the architect realized that temporary/vapor retarders could be installed as work surfaces, getting the building into the dry and allowing other trades to trash that rather than the finished roof, the roof system could be installed after those trades are off the roof.
  3. Coordinate with other disciplines. Roof systems cannot be designed in a vacuum. The architect needs to talk to and involve the structural, mechanical and plumbing engineers to ensure they realize the importance of essential details. For example, we cannot have steel angle around the drain whose flange rests on the bar joist, thus raising the roof deck surface at the roof drain. Ever wonder why you had ponding at the drain? Now you know. I attempt to always have a comprehensive, specific roofing detail on the structural, mechanical and plumbing sheets. I give the other disciplines my details and ask that they include them on their drawings, changing notes as required. That way, my 20-inch roof curb on the roof detail is a 20-inch curb on the mechanical sheets — not a standard 12-inch curb, which would more often than not be buried in insulation.
  4. Detail, detail, detail, and in case you glossed over this section, detail again. Make sure to include job-specific, clearly drawn details. Every condition of the roof should be detailed by the architect. Isn’t that what the client is paying for? Do not, as I once saw, indicate “RFO” on the drawings. Yes, that acronym stands for “Roofer Figure Out.” Apparently, the roofer did not figure it out. I enjoyed a nice Hawaiian vacation as a result of my work on that project, courtesy of the architect’s insurance company. How do you know that a condition works unless you design it and then draw it to scale?

    Figure 4: Insulation to curbs, roof edge and penetrations will not be tight, and to prevent a thermal short, the gaps created in construction need to filled with spray foam, as noted and shown here in this vent detail. Photos: Hutchinson Design Group

    I’ve seen roof insulation several inches above the roof edge because, OMG, the architect wanted gravel stop and forgot about camber. Not too big a deal (unless of course it’s a large building) to add several more layers of wood blocking and tapered edge strips at the now high wood blocking in the areas that were flush, but now the face of the roof edge sheet metal needs to increase. But what if the increase is above the allowable ANSI-SPRI ES1 standard and now a fascia and clip are required? You can see how the cost spirals, and the discussion ensues about who pays for what when there is a design error.

  5. Develop comprehensive specifications that indicate how the roof system components are to be installed. This requires empirical knowledge, the result of time on the roof observing construction. It is a very important educational tool that can prevent you, the designer, from looking like a fool.

Components

Best practices for single-ply membranes, in addition to the design elements above, also involve the system components. Below is a listing of items I feel embodies best practices for single-ply roof system components:

  1. Thicker membranes: The 45-mil membrane is insufficient for best practices, especially when one considers the thickness of the waterproofing over scrim on reinforced sheets. A 60-mil membrane is in my opinion the best practices minimum. Hear that? It’s the minimum. You are allowed to go to 75, 80 or 90 mils.
  2. Cover boards: A cover board should be specified in fully adhered and mechanically attached systems. (Ballasted systems should not incorporate a cover board.) Cover boards have enhanced adhesion of the membrane to the substrate over insulation facers and hold up better under wind load and hail. Cover boards also protect the insulation

    Photo 4: The greatest concern with the use of polyurethane adhesives is that the insulation board might not be not fully embedded into the adhesive. Weighting the boards at the corners and center with a minimum of 35 pounds for 10 minutes has proven to work well in achieving a solid bond.

    from physical damage and remain robust under foot traffic, while insulation tends to become crushed. Cover boards are dominated by the use of mat-faced modified gypsum products. Hydroscopic cover boards such as fiberboards are not recommended.

  3. Insulation: Now here is a product that designers seldom realize has many parts to be considered. First, let’s look at compression strength. If you are looking to best practices, 25 psi minimum is the way to go. The 18-psi insulation products with a fiber reinforced paper facer can be ruled out entirely, while 20 psi products are OK for ballasted systems. Now let’s look at facers. If you think about it for a second, when I say “paper-faced insulation,” you should first think “moisture absorbing” and secondly “mold growth.” Thus paper-faced products are not recommended to be incorporated if you are using best practices. You should be specifying the coated glass-faced products, which are resistant to moisture and mold resistant. A note to the manufacturers: get your acts together and be able to provide this product in a timely manner.

Additional considerations regarding insulation:

  • Insulation joints and gaps: You just can’t leave joints and gaps open. Show filling the open joints at the perimeter and curbs and around penetrations with spray foam in your details and specify this as well (see Photo 3 and Figure 4).
  • Mechanical attachment: Define the method of attachment and keep it simple. On typical projects, I commonly specify one mechanical fastener every 2 square feet over the entire roof (unless more fasteners are needed in the corners). Reducing the number of fasteners in the field compared to the perimeter can be confusing for contractors and the quality assurance observer, especially when the architect doesn’t define where that line is. The cost of the additional screws is nominal compared with the overall cost of the roof.
  • Polyurethane foam adhesive: Full cover spray foam or bead foam adhesive is taking over for asphalt, at least here in the Midwest, and I suspect in other local markets as well. The foam adhesive is great. It sticks to everything: cars, skylights, clerestories, your sunglasses. So, it is amazing how many insulation boards go down and don’t touch the foam. You must specify that the boards need to be set into place, walked on and then weighted in place until set. We specify five 35-pound weights (a 5-gallon pail filled with water works nicely), one at each corner and one in the middle for 10 minutes (see Photo 4). Yes, you need to be that specific.
  1. Photo 5: The design of exterior walls with metal studs that project above the roof deck is a multi-faceted, high-risk detail that is often poorly executed. Here you can see a gap between the deck and wall through which warm moist air will move and result in the premature failure of this roof. The sheathing on the wall cannot hold the horizontal base anchor screw, and the joints in the board allow air to pass to the base flashing, where is will condense. This is the type of architectural design that keeps on giving — giving me future work.

    Vapor/air barrier: A vapor air barrier can certainly serve more than a function as required for, say, over wet room conditions: pools, locker rooms, kitchens, gymnasiums. We incorporate them in both new construction and re-roofing as a means of addressing construction trade phasing and, for re-roofing, allowing time for the proper modification of existing elements such as roof edges, curbs, vents, drains, skylights and pipe curbs. Be sure to detail the penetrations and tie-ins with wall components.

  2. Deck type: Robust roof decks are best. Specify 80 ksi steel roof decks. Try staying away from joint spacing over 5 feet. Decks should be fully supported and extend completely to roof edges and curbs.
  3. Roof edge design: A key aesthetic concern, the termination point for the roof system, the first line of defense in regard to wind safety — the roof edge is all of these. The construction of the roof edge on typical commercial construction has changed drastically in the last 20 years, from brick and block to metal stud. Poorly designed metal stud parapets will be funding my grandkids’ college education. The challenge for the metal stud design is multifaceted: It must close off the chimney effect, prevent warm moist air from rising and condensing on the steel and wall substrate, create an acceptable substrate on the stud face in which to accept base anchor attachment, and — oh, yes — let’s not forget fire issues. Tread lightly here and create a “big stick” design (see Photo 5).
  4. Roof drains and curbs: As discussed above, there is a great need for coordination and specific detailing here. The rewards will be substantial in regard to quality and efficiency, minimizing time spent dealing with “what do we do now” scenarios.
  5. Slope: Design new structures with structural roof deck slope, then fine tune with tapered insulation.

Final Thoughts

Best practices will always be a balancing act between cost and quality. I believe in the mantra of “doing it right the first time.”

The industry has the material and contractors possess the skill. It’s the design and graphic communication arm that needs to improve to keep everyone working at the top of their game.

Designers, get out in the field and see the results of your details. See firsthand how a gypsum-based substrate board on a stud wall does not hold screws well; how a lap joint may not seal over the leading edge of tapered insulation; how the roof either ponds water at the roof drain or doesn’t meet code by drastically sumping; or how the hole cut in the roof membrane for the drain might be smaller than the drain bowl flange, thus restricting drainage. Seeing issues that the contractors deal with will help you as the designer in developing better details.

Contractors, when you see a detail that doesn’t work during the bidding, send in an RFI and not only ask a question, but take the time to inform the architect why you don’t think it will work. On a recent project here in Chicago, the architect omitted the vapor retarder over a pool. The contractor wrote an explicit explanation letter and RFI to the architect during bidding, and the architect replied, “install as designed.” In these situations, just walk away. For me, this is future work. A local contractor once told me, “I don’t get paid to RFI, I get paid to change order.” He also said, “If I ever received a response to an RFI, I would frame it!”

Manufacturers, too, can raise the bar. How about prohibiting loose base flashings at all times, and not allowing it when the salesman says the competition is allowing it. Have contractors on the cusp of quality? Decertify them. You don’t need the hassles. Owners don’t need the risk.

Seek out and welcome collaboration among contractors, roof systems designers, knowledgeable roof consultants, and engineers. Learning is a lifelong process, and the bar is changing every year. Too often we can be closed off and choose not to listen. At HDG, I am proud to say we have the building owners’ best interests at heart.

By all working together, the future of single-ply membranes can be enhanced and the systems will be retained when the next generation of roof cover arrives — and you know it will.

Roof Restoration Project Brings Back Luster to Quicken Loans Arena

The 170,000-square-foot roof of Quicken Loans Arena was completely restored using a liquid-applied system from Tremco Roofing. Photos: Tremco Roofing and Building Maintenance

Re-roofing sports and entertainment venues presents its own set of challenges. Sports arenas usually host concerts and other events, so scheduling and logistics can be difficult. Quicken Loans Arena in Cleveland — also known as “The Q” — is home to the Cleveland Cavaliers of the NBA, and it hosts some 200 other diverse events every year, including concerts and conventions. In 2015, realizing the roof was reaching the end of its useful life, the owners looked for advice on their next move. A team of roofing professionals recommended a roof restoration system that would provide the protection and recreate the aesthetics of the original roof — and keep disruption to the facility at a minimum.

Ohio companies stepping up to help the home team included architect Osborn Engineering, headquartered in Cleveland; roof consultant Adam Bradley Enterprises of Chagrin Falls; roofing manufacturer Tremco Roofing and Building Maintenance, headquartered in Beachwood; and roofing contractor Warren Roofing & Insulating Co., located in Walton Hills. After comprehensive testing revealed that more than 90 percent of the roof could be restored, they developed a plan to clean, repair and completely restore the 170,000-square-foot main roof of Quicken Loans Arena using a liquid-applied system from Tremco Roofing.

John Vetrovsky of Warren Roofing and Joe Slattery of Tremco Roofing shared their insights on the project with Roofing magazine. Both men were brought in during the planning stages of the project and saw it through to completion. “We were helping to budget the project with Adam Bradley and Osborn Engineering,” notes Vetrovsky. “They were asking about a few different systems, and the Tremco system was the best fit for the project.”

Warren Roofing has served the greater Cleveland and Akron area since 1922, and Tremco’s roots in northeast Ohio go back to 1928. Warren Roofing served as the general contractor and roofing contractor on the project. The scope of work included updates to the lightning protection system, the safety cable system, and the heat trace system used to melt snow in the gutters.

Repairing the Existing Roof

The existing system was the structure’s original roof. It was 24 years old, and consisted of a mechanically attached hypalon membrane over two layers of polyisocyanurate insulation totaling 3 inches. The roof membrane was showing some wear, and sections had sustained damage from an interesting source: fireworks from nearby Progressive Field, home of the Cleveland Indians, launched after the Indians hit home runs. After the damage was detected, the team changed the direction the fireworks were launched, and the problem ended.

Crews from Tremco Roofing cleaned the roof using the company’s RoofTec system, which recaptures the water and returns it to a truck to be filtered. Photos: Tremco Roofing and Building Maintenance

Despite the damage, visual analysis and a nuclear roof moisture test using a Troxler meter confirmed the roof was an excellent candidate for restoration. “There was some wet insulation and warped insulation, and we marked off those areas that had to be replaced,” notes Slattery. “It was a small fraction of the total job.”

Crews from Warren Roofing removed and replaced the damaged insulation, cutting through the membrane all the way down to the existing 6-mil vapor barrier on the deck. “All of that insulation had to be stair-stepped back so we could properly lap in the new material,” Vetrovsky says. “We got rid of all of the damaged insulation, and we repaired the vapor barrier. Then we staggered the two new layers of insulation, matching the existing thickness.”

Where possible, the existing membrane was pulled back and glued into place. In sections where new membrane was needed, crews adhered pieces of EPDM.

The plan specified adding the fasteners in the existing roof and any repaired sections before the coating system was applied. Tremco Roofing conducted uplift testing through Trinity ERD to ensure the results met or exceeded the specified design. “There was a significant upgrade to the fastening,” Vetrovsky says. “Because of the shape of the building, the perimeter enhancement was probably the greatest I’ve ever seen.”

Screws and 3-inch plates were used. In the field, the minimum was 4 feet on center, 12 inches apart. In the perimeter, fasteners were installed 2 feet on center, 8 inches apart. “It worked out nicely because the fastening ended up in the middle of the sheet, and now the sheet has fasteners that are original at the seam, and a foot or two over, there is a row of new fasteners,” notes Vetrovsky.

Cleaning Up

Prior to the fasteners being installed, the membrane was cleaned by crews from Tremco Roofing using the company’s RoofTec system. “We cleaned the membrane no more than 30 days ahead of what Warren Roofing was doing,” notes Slattery. “We had to mobilize at least three times to clean the roof so the time elapsed would never be more than 30 days.”

The three-step restoration process consists of a primer, a base coat with a fiberglass mat embedded in it, and a topcoat. Here, crews embed the fiberglass mat in the base coat. Photos: Tremco Roofing and Building Maintenance

The cleaning solution is applied using a custom-designed tool that looks like a floor polisher. It has a 2-foot diameter head that spins to clean the surface and a vacuum that recaptures the water, which is returned via hoses to a truck so contaminated waste water, environmental pollutants and high-pH cleaning solvents can be filtered out. “All of that water goes back into the sanitary system after it’s filtered,” Slattery explains. “It does not go into the sewer system.”

“It’s very fast, it’s very effective, and it’s very efficient because you can easily see the areas that have been cleaned,” notes Vetrovsky. “With power washing, you don’t have any way to filter the water.”

The biggest challenge on the cleaning portion of the project was the arena’s sheer size. Approximately 500 feet of hoses were needed to supply water and return it to the truck for filtering.

Cleaning of the substrate is a crucial step, according to Vetrovsky. “The system really does a nice job cleaning the membrane, and that is the key to any restoration project,” he says. “You’re only as good as the surface you’re applying it to.”

Applying the New Roof System

After the sections were cleaned, crews installed the liquid-applied AlphaGuard MT system. The three-step process consists of a primer, a base coat with a fiberglass mat embedded in it, and a topcoat. In this case, the primer was applied with rollers. “The area that we primed each morning was the section we would apply the first coat of AlphaGuard MT with the fiberglass mat that afternoon,” Vetrovsky says. “We did not prime ahead. We didn’t want to take the chance of dust adhering to the primer.”

The top coat was applied with both rollers and spray equipment. Photos: Tremco Roofing and Building Maintenance

Care had to be taken with the schedule to complete the work efficiently. “Once the base coat is on, you have 72 hours to apply the top coat,” Vetrovsky explains. “We would install the base coat and the fiberglass mat for two to three days to get a big enough area. The topcoat would go on faster because you’re not embedding any mesh into it. You really had to always keep an eye on the future weather to make sure you could get the topcoat on within the 72 hours.”

The topcoat was applied with both rollers and spray equipment. After the topcoat was applied, crews installed a second coat with sand embedded in it as a wear surface. Because of the roof’s curved surface, walk pads were not feasible, so the sand was used to provide additional traction for any workers conducting ongoing maintenance.

The sand was broadcast by hand and back-rolled into the coating to maintain a uniform appearance. “Part of this project was to make sure the sand looks uniform when it is visible from a blimp overhead,” notes Vetrovsky. “That was a difficult task, but the guys did a great job.”

The roof features three different finish colors, which were custom designed to match the roof’s original color scheme. The main roof is light gray, with black under the large LED sign. The sections over the wings are white, as are the 2-foot-wide stripes.

“They wanted black under the new LED sign so it would really show the letters nice and clear, even during the day,” says Vetrovsky. “We also put the white stripes back to match the roof’s original appearance. That was a challenge, to keep everything straight. It’s hard to chalk lines on a curve, but it came out nice. Everything matches what the original roof looks like.”

Penetrations for the sign included round posts that held the rails about 2-1/2 feet above the roof level. The liquid-applied membrane made coping with details easy, according to Vetrovsky. “The liquid membrane makes the flashing details all one piece with the roof system,” he says. “We removed the existing boot flashings so that we could seal directly to the conduit or steel posts.”

Gutters, Lightning Protection and Safety Systems

The large commercial gutters also needed to be refurbished. The gutters were 4 feet deep and 4 feet wide, and were outfitted with a cable snowmelt system, which had to be removed. “The gutters had a lot of damaged insulation, so material in the gutter sections was 100 percent torn off,” notes Vetrovsky.

After the roof surface was cleaned, the restoration system was applied. The three step process consists of a primer, a base coat with a fiberglass mat embedded in it, and a topcoat. Photos: Tremco Roofing and Building Maintenance

In the gutters, tapered insulation was installed, and a cover board — DensDeck from Georgia-Pacific — was added for increased durability. New EPDM membrane was installed and cleaned prior to the three-step coating application. New heat trace cable was also installed.

The lightning protection system also required repair, and close coordination with the subcontractors was critical. “The existing lightning protection had to be removed to apply the new roof system, but we couldn’t remove it 100 percent, because we still had to have an active lightning protection system for the building,” says Vetrovsky. “We rearranged the lightning system and installed new stanchions to try to eliminate as many horizontal lines as we could.”

During construction, key to the safety plan was a perimeter barrier system, which was installed by workers who were 100 percent tied off. After the system was in place, workers inside the barricades did not need to wear personal fall arrest systems. “The entire perimeter had a barricade system put on before any material was even loaded,” Vetrovsky says. The company makes its own barricade sections, which are anchored to the parapet walls and gravel stop edges and feature a downward leg for added support.

As part of the project, crews also installed permanent safety equipment. “There was an existing tie-off system out there, but it was not a certified system and we couldn’t use it,” Vetrovsky says. “We brought that to the owner’s attention and replaced it with a new certified tie-off system manufactured by Guardian Safety.”

Challenging Schedule

Progressive Field and the Quicken Loans Arena are right next to each other, and logistics and scheduling around the stadiums was difficult. Work began in 2016 and finished in 2017, and the demanding schedule was made even more difficult when both the Indians and the Cavaliers made deep runs into the playoffs. In 2016, the Cavs became NBA Champions. But it was the Indians making it to the 2016 World Series that posed bigger logistical problems for the re-roofing project.

The restored roof recreates the original color scheme, which features three different custom colors. The main roof is light gray, with black under the large LED sign, while the sections over the wings stripes are white. Photos: Tremco Roofing and Building Maintenance

“The first part of the schedule was the most difficult, as we had the get the black coating on the roof under the sign prior to the playoffs,” Vetrovsky says. The sign covered approximately 30,000 square feet of roof area, and it was difficult to access the roof surface beneath it. “Crews had to work on their hands and knees to apply the coating beneath the steel framing. That was towards the fall, when the weather started changing, and one of the biggest hurdles was just getting the roof dry in the morning. It got colder and colder as we got down to the wire, but we made our deadline for the work under the sign.”

The staging area was also limited, and the crane could only lift material to one section of the roof. Some material had to be moved by hand some 2,000 feet. “It was an awfully long walk from one end of that roof to the other,” Vetrovsky recalls.

Concerts and other events held during the construction cycle made the schedule even more challenging. “The most notable event was probably the Republican National Convention, which totally shut the site down for more than a week because of security,” notes Slattery.

Concerts usually necessitated loading in the early morning and clearing the staging area by 8 a.m., but usually work could continue during the day. “We had to do a lot of coordination to make sure we had what we needed to work the entire day and also not go against our commitment to the owner that we would not work past certain hours,” Vetrovsky says. “Many of the special events started after 7 p.m., so we would be long gone by then.”

Championship Caliber

The project was wrapped up earlier this year. Vetrovsky and Slattery agree that the system chosen was a great fit for this project for several reasons. With restoration, there is less noise, less disruption, and less equipment than with a re-roofing project, and the roof has a warranty for the next 20 years. The process also limits negative impact on the environment by preventing removal and disposal of the old roof system.

“The weight was also a factor,” notes Vetrovsky. “With the existing structure, there wasn’t a lot of room for a different type of roof system with heavy cover boards. This roof system was perfect because it doesn’t add a lot of weight.”

The coating also minimized installation time, notes Slattery. “The disruption of a roof replacement in a hospitality setting like that, where they need 250 days of revenue stream, restoration becomes a real attractive option,” he says. “I can’t think of one day where we really disrupted anything.”

Vetrovsky points to his talented crews as the key to meeting tough schedules with top-quality production “What we can offer is skilled labor,” he says. “We’re a union contractor and our guys are well trained. The harder, the better for us. We can handle projects that most other contractors won’t even put a number to — this project being one of those.”

He credits Adam Livingston, a third-generation foreman for Warren Roofing, for his work on the project.  “With his experience and attention to detail, we were able to complete this project on time, meet the expectations of the client and Tremco, and match the unique aesthetic requirements of the roof,” says Vetrovsky. “We have a lot of great employees who take pride in their work. Take all of that together, that’s why we can be successful on projects like the Quicken Loans Arena.”

The Cavaliers taking the NBA Championship during the project only added to the excitement. “It’s a great feather in our cap,” notes Slattery. “Restoration is a growing segment of the market. Instead of letting the clock run out on these roofs, if you catch them at the right time, it can be a phenomenal way to keep costs down and it’s good for the environment because it’s not adding waste to landfills.” 

TEAM

Architect: Osborn Engineering, Cleveland, Ohio, www.osborn-eng.com
Roof Consultant: Adam Bradley Enterprises, Chagrin Falls, Ohio, www.adambradleyinc.com
General Contractor: Warren Roofing & Insulating Co., Walton Hills, Ohio, www.warrenroofing.com

MATERIALS

Roof Cleaning System: RoofTec, Tremco Roofing, www.tremcoroofing.com
Roof Restoration System: AlphaGuard MT, Tremco Roofing

Three Sioux City Community School District Projects Are Part of Long-Term Plan

In 2017, Winkler Roofing crews re-roofed portions of two high schools and one elementary school. Shown here is an aerial photo of East High School. Photos: Mule-Hide Products Co. Inc.

For the Sioux City Community School District (SCCSD) in Sioux City, Iowa, the final dismissal bell of the school year marks more than the start of summer break for students and staff. It also signals the beginning of roofing season.

In addition to routine maintenance and repairs, each summer brings at least one major roofing project for the district and its 24 facilities. Existing roofs that have fallen out of warranty coverage are replaced. The district also has completed a steady stream of construction projects over the past 16 years, replacing aging schools to meet evolving needs.

District enrollment has increased by several hundred students over that timeframe and now stands at more than 14,500. SCCSD also has expanded its programming, creating specialty elementary schools focusing on STEM (science, technology, engineering and math), computer programming, environmental sciences, the arts, and dual-language education in English and Spanish. These specialties continue with middle school exploratory classes and eventually lead to the Sioux City Career Academy, which offers numerous education pathways to help students prepare for postsecondary education and careers.

Aerial view of West High School. Photos: Mule-Hide Products Co. Inc.

“Our facilities need to keep up with the curriculum and new technologies so we can provide the best possible learning environments for our students,” says SCCSD Director of Operations and Maintenance Brian Fahrendholz, adding that the facilities plan emphasizes both supporting student achievement and maintaining fiscal responsibility.

Winkler Roofing Inc. of Sioux City has been one of the district’s key partners in this process for more than 20 years, installing new or partial roofing systems on nearly every building in the district. The summer of 2017 saw its crews re-roof portions of two high schools and one elementary school, installing 335 squares of new TPO roof systems and removing 170 tons of ballast.

A crew of between six and nine professionals was on a jobsite at any given time. The three projects were completed in less than a month, beginning in late June and wrapping up in late July. And there was nothing on the punch list following the warranty inspections.

A Systematic Approach

In recent years, SCCSD has adopted a systematic, long-range-planning approach to roof system management, working with local architects to evaluate its facilities, identify and plan work that needs to be completed the following summer, and map out future projects. The three roofs replaced in 2017 were indicative of this approach.

TPO Bonding Adhesive is applied on the substrate and the back of TPO membrane. Photos: Mule-Hide Products Co. Inc.

Each of the roofs was between 15 and 20 years old and had begun to show signs of age. Their manufacturers’ warranties had also expired in recent years, making their replacement next up on the district’s roofing project schedule.

“We typically replace roofing systems within five years of the warranty expiration,” Fahrendholz explains. “It enables us to stay ahead of the maintenance issues that can begin cropping up.”

All three existing roofs had ballasted EPDM roofing systems. The re-roofing projects continued the district’s move toward TPO systems and, where possible, eliminating ballast. The three new roofing systems have 20-year, no-dollar-limit labor and material warranties.

SCCSD has several reasons for moving away from ballasted systems, according to Winkler Roofing President Jeff Winkler, P.E. In addition to reducing the roof’s weight and eliminating the cost of the ballast, unballasted roofs have a neater appearance and it is easier to monitor the membrane’s condition and find and repair any leaks. And, of course, when the time for re-roofing comes, there are no truckloads of ballast to remove and replace.

According to Winkler, SCCSD likes the durability of TPO membranes. “They like that the membrane is reinforced and that the seams are heat-welded, rather than seamed with primer and tape,” Winkler notes.

East High School Project

Re-roofing a 5,356-square-foot section at East High School entailed a complete tear-off of the existing ballasted EPDM roofing system and insulation down to the steel roof deck. The Winkler Roofing team then installed a new system topped with Mule-Hide TPO with CLEAN Film from Mule-Hide Products Co. It was the first time Winkler Roofing had installed the prodcut.

At East High School, polyisocyanurate insulation is installed using 3-inch galvalume plates and drill point fasteners. Photos: Mule-Hide Products Co. Inc.

Three layers of polyisocyanurate insulation were mechanically fastened with screws and plates to enhance the building’s energy efficiency. The 60-mil TPO membrane was then fully adhered using TPO Bonding Adhesive from Mule-Hide Products.

The last step in any well-done TPO project is removing the dirt and scuffs that are inevitably left behind during installation, notes Winkler. That step is eliminated with this product; the crew simply removes the protective film covering the membrane to reveal a clean roof that is ready for inspection.

“The material is more expensive than regular TPO membranes, but there is the potential to make up for that in reduced labor costs,” Winkler notes.

The biggest benefit would be seen on roofs that have fewer penetrations, according to Winkler. Installing the membrane around penetrations requires removing a portion of the protective film, he explains. Because those areas are then exposed to scuffs and dirt, crews must go back and clean them by hand.

West High School Project

Meticulous detail work was key to the successful replacement of a 18,056-square-foot section of the roof at West High School. There were nearly four dozen penetrations in the roof, from 4-inch pipes to HVAC equipment measuring 8 feet by 12 feet. Many of the chimney stacks also were in spots that were awkward for the crew to work around.

Winkler Roofing crew members prepare to install a TPO walkway pad. Photos: Mule-Hide Products Co. Inc.

It was all in a day’s work for the Winkler Roofing team. “The quality of our detail work is one of the things we take pride in,” Winkler says. “The keys are good leadership, both on and off the roof, and a well-seasoned crew. My foreman, Absalon Quezada, is a master of solving the toughest of details and coordinating a well-orchestrated crew.”

The roof’s existing concrete deck made a mechanically attached system uneconomical, so a new ballasted system was specified. The existing ballast had deteriorated to the point that, if reused, it could puncture the new roofing membrane. So, all 100 tons of it, along with the existing EPDM membrane, were removed and disposed of. The pieces of stainless steel cap metal along the perimeter were removed and numbered in sequence for reinstallation later. Sections of water-damaged insulation were removed and replaced.

An additional layer of polyisocyanurate insulation was loose-layered over the entire roof to improve energy efficiency, followed by a new loose-layered 60-mil white TPO membrane. New ballast was then installed.

Details such as this pipe boot were installed using a hot-air welder. Photos: Mule-Hide Products Co. Inc.

The crew navigated a challenging site while depositing the new ballast on the roof of the one-story building. The site offered only one feasible parking spot for the seven dump trucks that would deliver the rock, and that was on a lawn, just on the other side of two large trees. Crews carefully noted the location of sprinklers for the in-ground irrigation system to avoid driving over them, and shut the system down for several days in advance of the delivery to minimize ruts caused by the trucks’ tires. The trees’ trunks were spaced less than 20 feet apart and the canopies have grown together, leaving only small tunnel to feed the conveyor through. Crews kept the conveyor low as they extended it through the branches, then brought it to roof height by repeatedly raising it and the backing the truck up.

Riverside Elementary School Project

At Riverside Elementary School, a 7,314-square-foot section of roof was replaced with a 60-mil, fully attached TPO system.

The existing EPDM membrane, ballast and edge metal flashings were removed and disposed of. Crews removed and replaced any water-damaged insulation, added an additional layer of polyisocyanurate insulation throughout to increase the building’s energy efficiency, and mechanically attached the insulation to the steel roof deck using screws and plates. The white TPO membrane was then installed using bonding adhesive, and new edge metal flashings were added.

Straight A’s on the Report Card

The new roofs received top grades on their inspection report cards.

At East High School, crews installed Mule-Hide TPO with CLEAN Film from Mule-Hide Products Co. The last step in the installation process is removing the protective film covering the membrane. Photos: Mule-Hide Products Co. Inc.

When Mule-Hide Products Co. Territory Manager Jake Rowell inspected the roofs, there were no items on his, or the district’s, punch list. The only remaining task — which was completed during the inspection — was covering the seams on the West High School roof with ballast; they had intentionally been left exposed for easy inspection. In fact, that was the only “to-do list” item Rowell noted during inspections of 11 Winkler Roofing projects that week.

“The quality of their work is phenomenal,” Rowell says. “The crews take pride in their work. They don’t just throw a project together and move on. They check their work to make sure it’s done right before I see it and before the customer sees it.”

THE TEAM

Roofing Contractor: Winkler Roofing Inc., Sioux City, Iowa
Architect: FEH DESIGN, Sioux City, Iowa, www.fehdesign.com
Roofing Materials Distributor: ABC Supply Co. Inc., www.abcsupply.com
Decorative Sheet Metal: Interstate Mechanical Corp., Sioux City, Iowa, www.interstatemechanicalcorp.com

MATERIALS

TPO Membrane Roof Systems: Mule-Hide Products Co. Inc., www.mulehide.com

Research Centers Provide Valuable Information About Roof Performance

The Insurance Institute for Business and Home Safety Research Center evaluates construction materials and systems in its state-of-the-art testing laboratories. Photos: Insurance Institute for Business and Home Safety.

Until early October of this past year, Chester County, South Carolina, was home to a small, single-story house, similar to thousands of houses across the United States, but unique in almost every way.

What made this small structure one of a kind? The house sat inside the large test chamber at the Insurance Institute for Business and Home Safety (IBHS) Research Center, dwarfed by the six-story chamber’s cavernous interior. The house was built, in fact, to be destroyed.

On Oct. 5, the staff of the IBHS Research Center focused the test chamber’s intense destructive wind power, generated by 105 super-sized fans, on the small structure. Prior to the test, the center had digitized the wind record of an actual storm, and the wind speeds produced by the fans were varied accordingly. In the case of the simulated storm in early October, wind speeds were increased in three phases, up to 120 miles an hour. The house experienced significant damage to its walls and interior, and the garage door was ripped off. But the roof, built to IBHS’ recommended standards, held firm.

The IBHS research facility, which opened in 2010 and is funded by property insurers, evaluates various residential and commercial construction materials and systems. The lab is the only lab in the world that can unleash the power of highly realistic windstorms, wind-driven rain, hailstorms and wildfire ember storms on full-scale one- and two-story residential and commercial buildings in a controlled, repeatable fashion.

The mission of IBHS is to reduce the social and economic effects of natural disasters. And much of its research, like its attack on this small house last October, has focused, at least in part, on the resilience of roofs. As IBHS President and CEO Julie Rochman has noted, “The roof is your first line of defense against anything Mother Nature inflicts … and during a bad storm your roof endures fierce pressure from wind, rain, and flying debris.”

Educating the Industry

In May of 2017, the EPDM Roofing Association (ERA) launched a microsite to help educate the construction industry about the increasing need for resilience in the built environment, and the contributions that EPDM roofing membrane can make to a

IBHS conducts hail research in the Laboratory Building for Small Tests, where hailstones of various sizes are recreated and propelled against roof samples. Photos: Insurance Institute for Business and Home Safety.

resilient system. That effort came in response to the increasing number of extreme weather events. Since last May when ERA first launched its resilience microsite, the pattern of extreme weather has continued unabated, in the form of wildfires throughout the west which were exacerbated by extreme heat, and Hurricanes Harvey and Irma which left devastating floods and wind damage in their wake.

For more than a decade, ERA leadership has supported research about factors that contribute to the resilience of EPDM as a membrane, and how it best functions in various roofing systems. More recently, ERA has invested in site-visits to leading research organizations that generate science-based data about resiliency in building systems, first to Oak Ridge National Laboratories, near Knoxville, Tennessee, and then to the National Research Energy Laboratories (NREL) in Golden, Colorado. Given the complementary goals of ERA and IBHS to help support the creation of truly resilient buildings, ERA leadership welcomed the opportunity to visit the South Carolina research facility.

Analyzing Hail Damage

The hail research at IBHS was of special interest to ERA, given ERA’s research that has consistently shown that EPDM membrane offers exceptionally strong resistance against hail damage. Based on field and test data sponsored by ERA, EPDM roof membranes outperform other roof systems in terms of hail protection. In 2007, ERA conducted tests which showed that EPDM roofing membranes did not suffer membrane damage and avoided leaking problems endemic to other roofing surfaces in similar circumstances. Of the 81 targets installed for that research over different surfaces, 76 did not fail when impacted with hail ice balls up to three inches in diameter. Perhaps most importantly, the impact resistance of both field-aged and heat-aged membranes in this test also clearly demonstrated that EPDM retains the bulk of its impact resistance as it ages.

The IBHS Research Center’s super-sized fans can recreate winds to measure their effects on full-scale one- and two-story residential and commercial buildings. Photos: Insurance Institute for Business and Home Safety.

Using this ERA-generated research as a starting point, ERA leadership travelled to IBHS with specific questions in mind, including: What has IBHS research revealed about the impact of hail on various types of roofing membranes and systems? Does the IBHS research reinforce or contradict ERA’s findings? What are the next questions to be asked about the damage that hail can do, and are resilient systems cost-effective?

Hail research at IBHS is conducted in the Laboratory Building for Small Tests, a compact structure with equipment appropriate to replicate large hailstones and hurl them at roof samples. As part of its research, IBHS has worked with the National Weather Service to assess the geographic locations threatened by hail. Individual storms have long been recognized as creating widespread and expensive destruction, but is hail a threat that is confined to just a few specific geographic areas of the country?

In fact, more than 75 percent of the cities in the United States experience at least one hailstorm a year, and the risk extends across the country to all areas east of the Rockies. Annually, hail losses reach more than 1 billion dollars. The IBHS has identified the factors that contribute to the extent of hailstorm damage, with the impact resistance of roofing materials being one of the most critical factors, along with hailstone size, density and hardness. Likewise, the roof is one of the components most vulnerable to hail. Analysis of property damage resulting from a hailstorm in Dallas-Fort Worth in 2011 found that roof losses accounted for 75 percent of property damage in the area, and more than 90 percent of damage payouts.

In their efforts to replicate the true nature of hail, the staff at IBHS has conducted extensive fieldwork, and travelled widely around the United States to gather actual hailstones immediately after a storm. Over the last five years, the IBHS hail team has collected more than 3,500 hailstones, focusing on their dimensions, mass and compressive stress. The stones range from .04 inches in diameter to well over four inches. In addition, IBHS has conducted three-D scans of more than one hundred stones to further educate themselves about the true nature of hailstones, and how they contribute to the overall damage inflicted by hailstorms.

The research findings of IBHS reinforce or complement those of ERA. IBHS has found that unsupported roofing materials perform poorly and ballasted low-slope roofs perform especially well in hailstorms because they disperse energy. IBHS recommends that builders use systems that have impact resistance approval, including their own fortified standard. While IBHS found that newer roofing membranes perform better than older membranes, ERA studies found that new, heat-aged and field-aged EPDM membranes all offered a high degree of hail resistance, demonstrating that EPDM retains the bulk of its impact resistance as it ages.

Both organizations stress that resilient roofing systems in new and retrofitted construction can make good financial sense. According to Julie Rochman of IBHS, “We are really going to continue focusing on moving our culture from one that is focused on post-disaster response and recovery to pre-disaster investment and loss-mitigation … we’re going to be very focused on getting the roofs right in this country.”

For the members of ERA, “getting the roof right” has long been a dominant focus of their businesses. Now, in the face of increasingly frequent and extreme weather events, getting the roof right means gathering up-to-the-minute research about resilient systems, and putting that research to work to create resilient roofs.

Bi-Metal Drill Screws Feature Corrosion Resistance and Ductility

Triangle Fastener Corporation introduces a full line of 304 stainless steel bi-metal self-drilling screws.

Bi-metal screws have heads and threads made of 304 stainless steel providing corrosion resistance and ductility. A hardened carbon steel drill point welded to a stainless steel body, which allows the screw to drill and tap steel up to ½ inch thick.

The screws are used to attach aluminum, stainless steel, insulated metal panel (IMP) and when ductility is needed in the connection.

  • Available in #12 and ¼ inch diameters
  • Drill and tap up to ½ inch thick steel
  • Lengths up to 12 inches long
  • Head styles include: hex washer head, pancake head and button head
  • With and without EPDM Bond-Seal sealing washers
  • Can be painted to desired color

For more information, visit www.trianglefastener.com.