Electronic Leak Detection Testing System Developed for Black EPDM

Detec Systems has developed the IntegriScan scanning platform. According to the company, this is the only testing method capable of Electronic Leak Detection (ELD) testing of conductive membranes including Black EPDM and semi-conductive waterproofing systems. Black EPDM contains carbon black, which produces a level of electrical conductivity that makes testing impossible using high voltage and vector mapping.  

In order to enable valid ELD testing of Black EPDM, TruGround Conductive Primer must be applied directly below the membrane per ASTM D7877. TruGround can be used for quality assurance testing on newly installed, fully adhered or mechanically attached EPDM 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 to occur. The IntegriScan and TruGround are compatible with all membranes including EPDM, TPO, PVC, modified bitumen, and hot and cold fluid-applied waterproofing.

For more information, visit www.detecsystems.com.

What Can Visiting a Car Dealership Teach You About Closing Quotes After Roof Inspections?

Assessing a roof is easy. Assuming you have the basic technical skills, which are not difficult to learn, analyzing a roof and determining what deficiencies are present, what needs to be done, what can wait, all of that, really isn’t that hard to do.

So, why do so many roofing contractors have trouble selling the repairs their reports recommend? (And when they don’t sell the repairs they often think the problem is with their report format). Let’s see if we can bring some clarity to this.

Years ago, in my role as roofing consultant, I had a client give me a copy of an assessment report performed by a roofing contractor with a quote for about $36,000 of recommended repairs to correct deficiencies they found on a shopping center. I had also inspected the roofs and I agreed that everything they presented was a legitimate deficiency. So, what did I recommend to my client? I recommended we do none of it!

Let me give you a bit more information about the roof. In the three years that my client had owned the 84,000-square-foot shopping center, they have never had single roof leak and the well-installed gravel surfaced built up roofs were about eight years old. Do you really think a building owner is going to spend $36,000 on an 84,000-sqare-foot shopping center that had never leaked?

When you drop your car off at the body shop to have them fix a scratch on the right rear quarter panel on your car, you don’t expect them to fix the scratch, repaint the whole car, install new rims and tires, tint the windshield and upgrade the radio.

Tip 1: Most roofing contractors doing assessments produce reports and quotes “recommending” way too much work.  Just because something on a roof isn’t perfect doesn’t mean you have to fix it, at least right away. For instance, just because that EPDM wall flashing is starting to bridge, you and I both know it isn’t going to rip open for at least another three or four years and perhaps longer. (And there are exceptions, sure, but if you are on the roof regularly, monitoring it, there is no chance you won’t see it coming.) When you quote the repair of those flashings, it is the same as getting a quote to “install new tires and rims, tint your windshield and upgrade the radio” when you took your car in for that scratch on that right rear quarter panel.

There is another factor that comes in to play. When you dropped your car off at the body shop and when you see a quote to do all that unrequested work, you know you don’t need it. That isn’t the case with the typical building owner and his roofs.

The typical building owner, property manager, facility manager, building engineer, asset manager knows less about roofs than your receptionist. Think about that for a minute. While there are exceptions to this rule, they are few and far between. Do you know what that means? It means that they are not going to understand the report you produce. You can tell them what a flashing is and they will nod their head up and down. That doesn’t mean they understand. If you, instead, asked them to explain to you what a flashing is and you listen to their answer you will quickly discover that they have no real idea what a flashing is. But here is what they do know: They don’t need to spend $36,000 on a shopping center that doesn’t leak. Since they can’t understand your report, they just do none of it.

Tip 2: If you give them a laundry list of things to choose from, they will often choose “none of the above. ”So, make sure you explain why each of these things is necessary and the possible consequences of not doing them.

Tip 3: “Sell” your assessments as a way to manage an aging roof. While we can all agree that roofs should be inspected regularly, let’s also agree that the roofs that most need to be inspected regularly are aging (or problematic) roofs. Especially when you are trying to start work with a potential new client, point out that it is often possible to cost effectively extend the life of an aging roof, and the best way to figure out exactly if that might be possible and how to do it is with a formal assessment. Importantly, this also gives you a context for understanding what they are after and makes it much easier to avoid the issues mentioned in both Tips 1 and 2.

Let’s say you decide to buy a new car. You walk into the dealership and lady behind the desk says, “Just a minute, I’ll get somebody for you.” Shortly, a mechanic in greasy coveralls comes walking out the service area, wiping the grease off his hands with a rag. He walks you over to a car on the show floor and says, “You should buy this one. It is a real good car.” That isn’t how it works? Really? (And, do you think that mechanic should be surprised when you don’t buy that car? Then why are you surprised when your estimators only sell one in five estimates they put out for repairs?)

Does the professional salesman you actually buy your new car from know as much about how that car works as the mechanic? Probably not. Then why do you suppose auto dealers use salespeople to sell cars rather than mechanics or others with excellent technical expertise? Because salespeople know how to sell. In our industry, we routinely see commercial roofing service salespeople closing over 60 percent of their sales. Once you made the adjustments recommended in the first three tips, if you are not closing 60 percent or more of your service estimates coming off assessment reports, you need to follow the advice in Tip 4.

Tip 4: Hire a true sales professional to sell. When your payroll clerk and bookkeeper are both off work due to maternity leave and an auto accident, would you grab two guys from a tear-off crew and have them do the bookkeeping and payroll? If a couple of guys don’t show up on a Monday at the start of a large tear-off, do you send your payroll clerk and bookkeeper out to help with the tear-off? Then don’t expect the guy who you have assessing your customers’ roofs to also sell them the work you are quoting. Hire true sales professionals and watch your revenue grow.

By following these tips, the quality of your assessments will go up and so will your closing ratios.

New Roof Flashing Provides All-Weather Maintenance

New Seal-Fast Repair Hero roof flashing from Mule-Hide Products Co. is an all-system, all-weather maintenance and repair product.

A universal solution, the solvent-based, fiber-reinforced terpolymer sealant adheres to all roof substrates, including asphalt, modified bitumen, metal, TPO, EPDM, PVC, Kynar, concrete, Elvaloy/PVC, Hypalon (CSPE) and polyisobutylene (PIB).

Ready to work in all conditions, Repair Hero can be applied to dry or wet surfaces and under water. It can be used in any weather – rain or shine and in any ambient temperature.

According to the manufacturer, its exceptional elongation and high tensile strength enable Repair Hero to out-perform asphalt-based cements and silicone-based roof patches.

  • It delivers excellent adhesion, out-sticking silicone-based patches in TPO and EPDM applications.
  • It withstands soaring temperatures and intense exposure to ultraviolet light – conditions that can cause asphalt-based cements to become brittle and crack.
  • It is 50 percent more elastic and more than 9 times stronger than silicone-based roof patches, enabling it to better withstand building movement, foot traffic and the poundings dealt by Mother Nature.

Repair Hero complies with VOC-related regulations in all 50 states and does not need to be mixed or stirred before use and does not skin over or separate in the can after opening.

For more information, visit www.mulehide.com

 

Codes and Standards: Dealing With Decision Makers

During the past ten years, in my role as Associate Executive Director of the EPDM Roofing Association (ERA), much of my professional focus has been on monitoring the development of building codes and standards that could impact the products of our members, and the people who use those products. This past decade has been marked by intense debate, focusing on issues such as how the design of buildings can save energy, protect the health of the people who work there, and resist the ravages of increasingly frequent intense and even cataclysmic weather events. It has been an important time for the roofing industry to be engaged.

Given the complexity of the multiple codes and standards that impact roofing, it’s important to know the difference between codes and standards. To clarify, building codes are a set of rules that are frequently adopted into law, and are designed to specify the minimum requirements to safeguard the health, safety and welfare of building occupants. Building standards are set by national organizations such as ASHRAE and determine the performance requirements of the materials used in building construction. While standards are frequently incorporated into codes, that is not always the case.

Each year, ERA has increased its commitment of time and resources to stay abreast of proposed changes in codes and standards. As part of this commitment, I have sat through, and participated in, countless hours of codes and standards meetings and hearings, as well as related meetings with individuals and groups who share ERA’s goals. When I started out, I felt that it was important for members of the roofing industry to stay involved in the code and standard-setting processes. A decade later, I am convinced that participation by the roofing industry is essential if codes and standards are to support the best possible service and products that we can give our customers.

A few insights, based on my experience:

1. Science speaks.

ERA members, because of their close relationship with contractors and consultants, want to make sure that the choice of building materials is left in the hands of the design professional, the consultant, the architect, the engineer, the contractor and, of course, ultimately the building owner or facility manager. When we have codes and standards that do not reflect science-based evidence and/or the best practices within the roofing industry, then those stakeholders may not be able to choose the best product for the job at hand. In some cases, proposed modifications to existing codes or standards are suggested by people from the industry. In those instances, our role is to provide research and evidence to support the proposed change. Either way, science-based testimony usually carries the day. Not always, but without good scientific evidence to support a specific position, the chances of winning are nil to none. It takes time and clear thought to influence the codes and standards process, but without a base of indisputable scientific evidence, it’s hard to get out of the starting gate.

2. Collaboration is essential.

We have always welcomed forging partnerships with like-minded roofing professionals. But there have also been times when we have acted as consulting partners with regulatory agencies. A recent example: when regulatory agencies across the Northeast and Mid-Atlantic states were charged with improving air quality, they chose to reduce the amount of allowable volatile organic compounds, or VOCs, in adhesive sealants. This was a very good idea, and the industry was certainly supportive of the intent, but the way in which many of those states intended to enact those VOC regulations would have crippled the roofing industry. Essentially, the agencies were taking a regulation that was written for the state of California and applying it universally across the New England and Mid-Atlantic States.

So, ERA conducted studies, showing how the climate of those Northeastern and Mid-Atlantic states was dissimilar from the climate of California. We also provided technical information on how product would react differently in those different climates, and then we asked for a delayed implementation period to allow the research and development divisions in our companies to develop new products. These new products are appropriate for use in the climates in question and still allow the regulatory agencies to achieve their goals, successfully reducing the amount of the VOCs. Our participation was essential to help the regulatory agencies draw up a realistic timeline that would take into account the needs of the roofing industry.

3. Monitor the decision makers.

It’s important to monitor the discussion surrounding any proposed changes in codes and standards. It’s equally as important to monitor who will be making the final decisions on these issues. Since there are various facets of the roofing industry, code-setting bodies would be wise to ask the local roofing experts for advice on whom to include in their decision-making process. I’ve seen instances where committees have incorporated someone who may technically be from the roofing industry, but that person’s breadth and depth of knowledge is not appropriate for the topic at hand.

I would say we have seen mismatch of decision makers when urban heat island and cool roof issues are being debated. An individual may know a fair amount about climate change, but that doesn’t mean the person necessarily understands the nuances of cool roofing. Additionally, they may not be aware of the breadth of research on that topic and instead rely on dated information from college or grad school without being appropriately briefed on new and emerging research.

4. Prepare for a variety of responses.

We have worked with some regulatory agencies during a collaborative process and they’ve been very grateful for our input. There have been other situations where it seems that the policymakers just want us to rubber stamp their very well-intentioned but ill-conceived draft codes. That’s not something that we are willing to give. These initiatives, these outreach campaigns, take a tremendous amount of time and effort and financial resources, and difficult as it may be, our members feel that they owe it to the industry and their customers to make sure that anything that we’re involved in is done the right way and rooted in science-based evidence. There are no shortcuts in these sometimes very difficult fights.

5. Everyone can contribute.

Every member of the roofing community can be active and engaged and make a contribution to ensuring that codes and standards reflect the true needs of the construction industry and our customers. It’s very valuable to build relationships with state legislators and attend town hall meetings. It is crucial to identify candidates that are pro-business and pro roofing, and support them financially as well as from an educational perspective by sharing information with them about the roofing industry.

This is also critically important: When you are asked to write a letter to a key decision maker, be sure to do it. Recently, as part of a campaign to preserve choice of building products for roofers, I visited a city councilmember’s office. On the wall was an enormous white board where every single constituent member’s concern was tracked, along with a reference to the response. This particular city council member had an 87 percent “close rate,” meaning that 87 percent of the concerns that they had received in a given period had been responded to. My experience has been that municipal and state legislators take constituent outreach very, very seriously. Every letter, every e-mail makes a difference.

6. Gather intelligence for your professional organization.

If there is one takeaway that I want people to get from this article, it is to keep us informed. It is darned near impossible to track everything that happens on a city, county, state and national basis because there is no software that currently tracks these issues before they are formally proposed and published for review. And that is often too late to educate the policy makers. It is critical for the readers of this article to attend their local trade association meetings and become acquainted with the policy makers and the legislators in their area. Equally as important, everyone can become a resource for legislators and policymakers when they have a question about roofing.

I’m looking forward to the next decade of victories for the roofing industry, allowing us to deliver superior roofing systems to a broad range of customers. But this will happen only if key decisions about the roof are made by roofing experts, and not mandated by politicians who are far removed from the design process.

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.