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.

SPRI Updates and Improves Roof Edge Standards

Low-slope metal perimeter edge details, including fascia, coping and gutters, are critical systems that can strongly impact the long-term performance of single-ply roofs. Photo: Johns Manville

The effect of high winds on roofs is a complex phenomenon, and inadequate wind uplift design is a common factor in roofing failures. Damage from wind events has historically been dramatic, and wind-induced roof failure is one of the major contributors to insurance claims.

Roofing professionals have long recognized the importance of proper low-slope roof edge and gutter designs, particularly in high-wind conditions. For this reason, SPRI, the association representing sheet membrane and component suppliers to the commercial roofing industry, has spent more than a decade enhancing testing and design standards for these roofing details.

SPRI introduced the first version of its landmark standard, ANSI/SPRI/ES-1 “Wind Design Standard for Edge Systems Used with Low Slope Roofing Systems” in 1998. Since then, the association has continually revised, re-designated and re-approved the document as an ANSI (American National Standards Institute) standard.

Testing of edge securement per ANSI/SPRI ES-1 is required per the International Building Code (IBC), which has been adopted by every state in the country.

This standard provides the basic requirements for wind-load resistance design and testing for roof-edge securement, perimeter edge systems, and nailers. It also provides minimum edge system material thicknesses that lead to satisfactory flatness, and designs to minimize corrosion.

Construction professionals have been successfully using the standard, along with the specifications and requirements of roofing membrane and edge system manufacturers to strengthen their wind designs.

Until recently, the biggest news on the wind design front was the approval of ANSI/SPRI/FM 4435/ES-1, “Wind Design Standard for Edge Systems Used with Low-slope Roofing Systems.” Let’s call it “4435/ES-1” for short. SPRI knew recent post-hurricane investigations by the Roofing Industry Committee on Weather Issues (RICOWI) and investigations of losses by FM Global consistently showed that, in many cases, damage to a low-slope roof system during high-wind events begins when the edge of the assembly becomes disengaged from the building. Once this occurs, the components of the roof system (membrane, insulation, etc.) are exposed. Damage then propagates across the entire roof system by peeling of the roof membrane, insulation, or a combination of the two.

Recognizing that edge metal is a leading cause of roof failures, SPRI has redoubled its efforts to create a series of new and revised documents for ANSI approval. As has always been the case, ANSI endorsement is a critical step toward the ultimate goal of getting these design criteria included in the IBC.

A Systems Approach to Enhancing Roof Edge Design

Roofing professionals understand that successful roof design requires the proper integration of a wide variety of roofing materials and components. For years, leading roofing manufacturers have taken a “systems” approach to their product lines. Recently, SPRI has zeroed in on the roof edge. Low-slope, metal perimeter edge details include fascia, coping and gutters, are critical systems that can strongly impact the long-term performance of single-ply roofs.

As part of the ES-1 testing protocol, RE-3 tests upward and outward simultaneous pull of a horizontal and vertical flanges of a parapet coping cap. Photo: OMG Edge Systems

SPRI first addressed roof gutters in 2010 with the development of ANSI/SPRI GD-1. The testing component of this document was recently separated out to create a test standard and a design standard. The test standard, GT-1, “Test Standard for Gutter Systems,” which was approved as an American National Standard on May 25, 2016.

Similarly, SPRI has revised 4435/ES-1 to only be a test standard.

Making both edge standards (4435/ES-1 and GT-1) into standalone testing documents makes it easier for designers, contractors and building code officials to reference the testing requirements needed for metal roof edge systems.

IBC requires that perimeter edge metal fascia and coping (excluding gutters), be tested per the three test methods, referred to as RE-1, RE-2 and RE-3 in the ES-1 standard. The design elements of ES-1 were never referenced in code, which caused some confusion as to how ES-1 was to be applied. The latest version of 4435/ES-1 (2017) only includes the tests referenced in code to eliminate that confusion.

Test methods in 4435/ES-1 2017 have the same names (RE-1, RE-2, and RE-3), and use the same test method as 4435/ES-1 2011. Because there are no changes to the test methods, any edge system tested to the 2011 version would not need to be retested using the 2017 version.

FM Global’s input was instrumental in the changes in 2011 when ANSI/SPRI ES-1 incorporated components of FM 4435 to become 4435/ES-1. However, there are no additional FM related changes in the latest 4435/ES-1 standard.

This gravel stop is being tested according to the ANSI/SPRI ES-1 standard using the RE-2 test for fascia systems. Photo: OMG Edge Systems

Per ANSI requirements, 4435/ES-1 2011 needed to be re-balloted, which is required by ANSI every five years. SPRI took this opportunity to have it approved as a test standard only to eliminate the confusion referenced above. FM Global was consulted and indicated it wanted to keep “FM” in the title. (FM was on the canvas list for the test standard and actually uses it as its own test standard.)

With 4435/ES-1 becoming a test standard for coping and fascia only, and GT-1 being a test standard for gutters, SPRI determined that a separate edge design standard was needed. Meet ED-1, a design standard for metal perimeter edge systems.

The design portions of the ES-1 edge and the GD-1 gutter standards have been combined and are now referenced by SPRI as ED-1. It has been developed and is currently being canvassed as an ANSI standard that will provide guidance for designing all perimeter edge metal including fascia, coping, and gutters.

ED-1 will be canvassed per the ANSI process later this year. However, SPRI is not planning to submit ED-1 for code approval.

SPRI ED-1 will include:

Material Design

  • Nailer attachment
  • Proper coverage
  • Recommended material thicknesses
  • Galvanic compatibility
  • Thermal movement
  • Testing requirements
  • “Appliance” attachment to edge systems

Limited Wind Design

  • Load to be required by the Authorities Having Jurisdiction (AHJ).
  • Tables similar to those included in 4435/ES-1 will be included for reference.

If this sounds a tad complex, imagine the design work required by the dedicated members of SPRI’s various subcommittees.

The Test Methods in Detail

The GT-1 standard is the newest, so let’s tackle this one first. As noted above, the ANSI/SPRI GT-1 test standard was developed by SPRI and received ANSI Approval in May of 2016. Testing of roof gutters is not currently required by IBC; however, field observations of numerous gutter failures in moderate to high winds, along with investigations by RICOWI following hurricanes have shown that improperly designed or installed gutters frequently fail in high wind events. GT-1 provides a test method that can be used by manufacturers of gutters, including contractors that brake or roll-form gutters, to determine if the gutter will resist wind design loads. Installing gutters tested to resist anticipated wind forces can give contractors peace of mind, and may provide a competitive advantage when presented to the building owner.

This gutter is being tested using the test method specified in ANSI/SPRI GD-1, “Design Standard for Gutter Systems Used with Low-Slope Roofs.” Photo: OMG Edge Systems

GT-1 tests full size and length samples (maximum 12 feet 0 inches) of gutter with brackets, straps, and fasteners installed per the gutter design. It is critical that the gutter be installed with the same brackets, straps, and fasteners, at the same spacing and locations as per the tested design to assure the gutter will perform in the field as tested. The fabricator should also label the gutter and/or provide documentation that the gutter system has been tested per GT-1 to resist the design loads required.

GT-1 consists primarily of three test methods (G-1, G-2, and G-3). Test method G-1 tests the resistance to wind loads acting outwardly on the face of the gutter, and G-2 tests the resistance to wind loads acting upwardly on the bottom of the gutter. G-3 tests resistance to the loads of ice and water acting downwardly on the bottom of the gutter.

Tests G-1 and G-2 are cycled (load, relax, increase load) tests to failure in both the original GD-1 standard and the new GT-1. The only change being that in GD-1 the loads are increased in increments of 10 lbf/ft2 (pound force per square foot) from 0 to failure, and in GT-1 they are increased in increments of 15 lbs/lf (pounds per linear foot) from 0 to 60 lbs/lf, then in 5 lbs/lf increments from above 60 lbs/lf to failure.

Note also that the units changed from lbf/ft2 (pound force per square foot) to lbs/lf (pounds per linear foot), which was done so that the tests could be run using the test apparatus loads without having to convert to pressures.

The GT-1 standard specifies a laboratory method for static testing external gutters. However, testing of gutters with a circular cross-section is not addressed in the standard, nor does the standard address water removal or the water-carrying capability of the gutter. In addition, downspouts and leaders are not included in the scope of the standard.

SPRI intends to submit ANSI/SPRI GT-1 for adoption in the next IBC code cycle.

As referenced above, IBC requires that perimeter edge metal (fascia and coping), excluding gutters, be tested per three test methods, referred to as RE-1, RE-2 and RE-3 in the ES-1 standard.

RE-1 tests the ability of the edge to secure a billowing membrane, and is only required for mechanically attached or ballasted membrane roof systems when there is no peel stop (seam plate or fasteners within 12 inches of the roof edge). RE-2 tests the outward pull for the horizontal face of an edge device. RE-3 tests upward and outward simultaneous pull on the horizontal and vertical sides of a parapet coping cap.

Calculating Roof Edge Design Pressures

All versions of ANSI/SPRI ES-1 and ANSI/SPRI GD-1, the 2011 version of ANSI/SPRI 4435/ES-1, and the new ED-1 standard all provide design information for calculating roof edge design pressures. These design calculations are based on ASCE7 (2005 and earlier), and consider the wind speed, building height, building exposure (terrain), and building use.

A gravel stop failure observed during roof inspections after Hurricane Ike in Sept. 2008. Photo: OMG Edge Systems

However, as stated above, IBC requires that the load calculation be per Chapter 16 of code, so the SPRI design standards are intended only as a reference for designers, fabricators, and installers of metal roof edge systems.

ES-1-tested edge metal is currently available from pre-manufactured suppliers, membrane manufacturers and metal fabricators that have tested their products at an approved laboratory.

The roofing contractor can also shop-fabricate edge metal, as long as the final product is tested by an approved testing service. The National Roofing Contractors Association (NRCA) has performed lab testing and maintains a certification listing for specific edge metal flashings using Intertek Testing Services, N.A. Visit www. nrca.net/rp/technical/details/files/its details.pdf for further details.

A list of shop fabricators that have obtained a sub-listing from NRCA to fabricate the tested edge metal products are also available at www. nrca.net/rp/technical/details/files/its details/authfab.aspx.

SPRI Continues to Take Lead Role in Wind Testing

As far back as 1998, SPRI broke ground with its ANSI/SPRI/ES-1 document addressing design and testing of low-slope perimeter edge metal. Today, the trade association has a variety of design documents at the roofing professional’s disposal, and is working to get ED-1 approved as an Edge Design Standard to be used for low-slope metal perimeter edge components that include fascia, coping and gutters.

All current and previously approved ANSI/SPRI standards can be accessed directly by visiting https://www.spri.org/publications/policy.htm.

For more information about SPRI and its activities, visit www.spri.org or contact the association at info@spri.org.

Bonding 101: What Do Roofing Contractors Need to Know About Bonds?

In a number of states, roofing contractors need to get licensed in order to perform roofing work. Obtaining a roofer license bond is a common licensing requirement. Not all states require a roofing contractor license and bonding, but contractors may have to get a bond to meet county criteria, too.

Even if you’re not new to bonding, the concept of how surety bonds work may be a bit difficult to grasp. However, it’s important to understand the basics if you need to get bonded as a part of your contractor licensing.

Besides a legal requirement to fulfill, bonds are also a strong sign for your customers that you are safe to do business with. Being licensed and bonded is one of your advantages on the market.

Here’s an overview of the states which require roofing contractors to obtain a bond, as well as the most significant facts about bonding that matter for your roofing business.

Where You Need to Post a Roofing License Bond

There is no nationwide requirement for roofing license and bonding. Each state defines its rules regulating roofing specialists. Usually state contractor license boards are in charge of the licensing process. They include roofing as one of the specialty contractor licenses that can be obtained. Additionally, towns and counties may impose their own licensing requirements for contractors operating on their territory.

If you want to operate in California, Texas, Minnesota, Oklahoma, Illinois, or Arizona, you will have to obtain a roofing contractor license and bond. The bond amount in Oklahoma is $5,000. In Illinois it is $10,000. California and Minnesota roofers have to obtain a $15,000 bond. Roofers in Texas have to post the biggest bond amount—$100,000.

Town and county licensing varies across the country, so it’s best to check with your local authorities about their exact requirements and bond amounts. In some cases, you will need to obtain a general contractor license and bonding, while other licensing bodies will require a special roofing license and bond.

How Surety Bonds Work

Roofer license bonds are a type of contractor license bonds, which are required from a number of construction specialists. As such, they are a contract between your roofing business, the licensing authority, and a surety. The bond provider backs your contractorship and guarantees financially for you in front of the local or state body issuing your license.

In order to get bonded, you need to pay a bond premium. It is a small percentage of the bond amount that you have to obtain. The premium is determined on the basis of your financial situation. Your surety provider examines your personal credit score, as well as business finances and any assets and liquidity. That’s how it can assess how risky your profile is.

If your finances are in good shape, your bond premium is likely to be in the range of 1 percent to 5 percent. For a $15,000 bond, this can mean a bond price of $150-$750. To reduce your bond premium, you can work on improving your credit score and financials before you apply for the bond.

As you need to stay bonded throughout your licensing period, you can decrease your bond cost with every bond renewal.

Responsibilities Under the Bond

Licensing authorities require a surety bond from roofing specialists in order to exercise a higher level of control over their operations. The purpose of the bond is to protect your customers.

However, it does not protect your business like insurance does, for example. It ensures your compliance with relevant laws by providing an extra layer of guarantee for the general public. In practical terms, this means an extra assurance that you will perform the contractual roofing work you have committed to.

In case you transgress from your contractual and legal obligations, the bond can provide a financial compensation for an affected party via a claim. Such situations include not completing the work you have agreed to in a contract, delaying the completion, delivering low-quality work, or similar issues with performing your contractual agreements.

If a claim against you is proven, you are liable to reimburse the claimant up to the penal sum of your bond. If your bond is, say, $15,000, that’s the maximum compensation that can be claimed.

At first, your surety may cover the claim costs. This is the immediate protection for consumers who have been negatively affected by your actions. However, your responsibility under the bond indemnity agreement is that you have to repay the surety fully. This means that the surety bond functions similarly to an extra line of credit, which is extended to your business temporarily.

Bond claims can be quite costly for your business, not only in terms of finances, but also by harming your reputation as a professional in the field. The wisest course of action is to avoid them.

Roofing contractors in a number of states have to obtain a surety bond as a part of their licensing. If you’re launching your business as a roofer, make sure to check with your state authorities about the requirements you have to meet. This will ensure your legal compliance, as well as a smooth start in your trade.

About the Author: Todd Bryant is the president and founder of Bryant Surety Bonds.

Learn to Delegate: Determine Which Tasks You Can Let Go and Concentrate on Your Zone of Genius

You have 168 hours each week to design your life. You use some of the hours for sleeping, some for exercising, some for eating, some for showering, some for work, and some for family—but when you run out of your 168 hours, you are out!

Time is the one commodity you can’t create more of. Once it is gone, it is gone. You can always make more money; you can’t make more time. Or can you?

You are limited in what you can accomplish each week by the mere fact you only have 168 hours. However, there is no limit to what can be accomplished each week if more people pitch in to help.

When you effectively delegate some tasks, it’s like adding 10, 20, 40, 80, 800 hours to your week. It’s almost as if you are creating more time each week.

When I work with clients, one of the first things they share with me is they just aren’t sure what they can delegate. They admit that delegating, in theory, makes sense. However, they aren’t sure how to apply it to their business.

There isn’t a “one size fits all” solution to the delegation challenge. However, there is a process you can follow to find a solution that works for you.

Use the Acronym A.W.E.

You can determine which tasks to delegate by following a three-step process represented by the acronym A.W.E.

  • A—Awareness. What are some of the tasks currently on your plate?
  • W–Work. How do you decide which tasks to delegate?
  • E–Evaluation. What worked and how do you do more of it?

Get ready to delegate! The following exercise will take about 20 minutes to complete–and the payoff is you’ll gain a minimum of three hours of you do it effectively. That’s pretty good ROI on 20 minutes, wouldn’t you agree?

Awareness: The exercise begins by defining what is important and determining what is on your plate.

Step #1: List your top 3 goals.

Step #2: What is your Zone of Genius? That is, list the things in your life and your business that only you can do. (Hint: If you are honest, this list should be pretty short.)

Step #3: Next, list all the things that you “don’t have time to do.” What are the tasks you put off because you don’t like doing them? What are the tasks you are waiting to start until the “timing is right”?

Step #4: Pull out to-do list out from the last week and your to-do list for next week.

Work: At the next stage, you can start to narrow down the tasks you can delegate.

Step #5: Look at your to-do list and your “I don’t have time to do this” list, and for each task, ask yourself, “What goal does this task support?” Write the corresponding goal next to the task. (Hint: Writing the goal down ensures you don’t just skip this part.)

Step #6: You are almost finished with the exercise now! Put a smiley face next to all the tasks that line up directly with your Zone of Genius.

Step #7: Circle the items that relate to a goal, but do not have a smiley face. These are the tasks in your business or life that can be delegated. They support a goal and they are not in your Zone of Genius. They don’t need to be done by you to be done effectively. (Bonus tip: If a task doesn’t directly support a goal, why are you doing it?)

Step #8: Delegate at least three of these tasks.

Evaluation: Determine how effectively each task you delegated was completed and how much time it saved you. Do more of what works! When you can do more of what works and less of what doesn’t, life becomes much easier. Yet many people forget to slow down long enough to think through what is working. Take 10 minutes to check back at the end of the week and ask yourself these questions: Who was a great delegating resource? What tasks were easy to let go of? What tasks do you want to outsource next? Where were the struggles? How can you fine-tune the process?

Congratulations! You have at least three tasks circled. Start delegating and start increasing the number of hours you have available each week to accomplish your goals.

Remember, this process is not a one-and-done kind of thing. To be effective, as your tasks and goals change, the evaluation process becomes more important. Regular process improvement means you are always on task for your Zone of Genius!

Efficient and Effective Construction Through Building Codes

This fire station roof assembly includes thermally efficient cross-ventilated non-structural composite insulation manufactured by Atlas Roofing and installed by Utah Tile & Roofing.   Photos: Atlas Roofing Corp

This fire station roof assembly includes thermally efficient cross-ventilated non-structural composite insulation manufactured by Atlas Roofing and installed by Utah Tile & Roofing. Photos: Atlas Roofing Corp

In a world where the bottom line is a critical concern in any construction project, conscientious design and roofing professionals look at the lifetime costs of a building instead of just the short-term construction outlay. Choices made during a building’s initial design and construction have long-term influence on the lifetime of its operation and maintenance. With so many building products and options available, building codes take on a vital role in guiding decisions about building quality, safety, and energy performance. These trusted benchmarks, compiled with input from a broad range of stakeholders, are designed to ensure that the best technologies, materials, and methods are used in construction.

Building Energy Codes 101

Model building energy codes are revised every three years to incorporate the latest research and ensure that new and existing buildings benefit from the methods and products that will produce the most value and safety over time. The International Energy Conservation Code (IECC) and ASHRAE set standards tailored to specific climate zones and include options to provide flexibility in choosing the methods and materials best suited to each project’s needs while nevertheless meeting the requirements. Without regular, incremental improvements to these codes, new buildings would be dated even before their construction begins.

Indeed, while some building features are straightforward to replace and upgrade over time, some of the most vital elements of building performance need to be “designed in” at the outset. Codes are designed to lock in savings during initial construction or major renovations to promote cost-effective design and construction practices. For example, roof replacement projects provide an opportunity to cost-effectively improve the overall energy efficiency performance of buildings.

Energy-efficient design strategies are helpful to all building owners, including government and municipal projects built with taxpayer funding. Pictured here is Fire Station #108 in Brighton, Utah. Photos: Atlas Roofing Corp.

One of the major benefits of building code updates in recent years is the focus on energy efficiency and resiliency. The Insurance Institute for Business and Home Safety writes that, “Over the centuries, building codes have evolved from regulations stemming from tragic experiences to standards designed to prevent them.” With the ongoing effects of climate change, buildings are subjected to extremes of weather and temperature that challenge the performance of their systems. Most structures built over the previous century were not designed or constructed with energy efficiency in mind and suffer from poor insulation and dramatic thermal loss. Buildings account for over 40 percent of America’s total energy consumption, 74 percent of our electricity, and cause 40 percent of our greenhouse emissions. Implementing best practices for sustainable design and utilizing highly efficient building materials like insulation could save billions of dollars a year and improve the reliability of the electrical grid systems.

Energy-Efficient Roofing

A report prepared in 2009 by Bayer MaterialScience (now Covestro), “Energy and Environmental Impact Reduction Opportunities for Existing Buildings with Low-Slope Roofs,” determined that going from an R-12 insulation level (i.e., the average R-value of roofs on older buildings) to R-30 would pay for itself in energy savings in just 12 years with an average reduction in building energy use of 7 percent. Better roof insulation also saves money on equipment, since buildings with weaker envelopes require larger and costlier HVAC systems and future upgrades to HVAC equipment that is smaller and less expensive will always be limited by this constraint.

These savings are not only confined to new construction. In renovations, the removal and replacement of a roof membrane offers the best and most cost-effective opportunity to improve a building’s thermal envelope and better position that building for energy-efficiency upgrades down the road.

Energy Efficiency in Government Buildings

While these strategies are helpful to all building owners, they are especially important for government projects built with an increasingly tight supply of taxpayer dollars. Here is another place where the building codes provide a major assist. For federal commercial and multi-family high-rise residential buildings where the design process began after Nov. 6, 2016, agencies are required to design buildings to meet ASHRAE 90.1-2013 and, if life-cycle cost-effective, achieve energy consumption levels that are at least 30 percent below the levels of the ASHRAE 90.1-2013 baseline building. These savings are calculated by looking at the building envelope and energy consuming systems normally specified by ASHRAE 90.1 (such as space heating, space cooling, ventilation, service water heating, and lighting but not receptacle and process loads not covered by 90.1).

Photos: Atlas Roofing Corp.

Changes in the 2013 edition of ASHRAE 90.1 clarify the insulation requirements of various low-slope re-roofing activities. New definitions of “roof covering” (the topmost component of the roof assembly intended for weather resistance, fire classification, or appearance) and “roof recovering” (the process of installing an additional roof covering over an existing roof covering without removing the existing roof covering) were added and the exceptions to the R-value requirement for roof replacements were clarified to include only “roof recovering” and the “removal and replacement of a roof covering where there is existing insulation integral to or below the roof deck.” In all other instances, when a roof membrane is removed and replaced, the insulation must be brought up to current R-value requirements, which range from R-20 to R-35, depending on climate zone. In addition, the prescriptive R-value requirements for low-slope roofs under 90.1-2013, as compared to previous version (90.1-2010), are higher. For instance, in populous climate zones 4 and 5 the R-values for these roofs increased from R-20 to R-30.

The Department of Energy is preparing to start a rulemaking process to update the federal building energy standard baseline to the 90.1-2016 Standard, which will provide about an 8 percent improvement in energy cost savings compared to 90.1-2013. However, no changes were made to the R-values for low-slope roofs. Managers of federal buildings are working to comply with updated directives that impact new construction and building alterations, including:

  • “Guiding Principles for Federal Leadership in High Performance and Sustainable Buildings”
  • GSA PBS-P100 “Facilities Standards for the Public Buildings Service”
  • DOD’s Unified Facilities Criteria (UFC).

The instructions in these publications coupled with Executive Order 13693, issued on March 15, 2015, and “Guiding Principles for Sustainable Federal Buildings,” require new and existing federal buildings to adopt improved energy efficiency and “green building” attributes. New buildings are expected to “employ strategies that minimize energy usage” and existing ones must “seek to achieve optimal energy efficiency.” These directives require:

  • Regular benchmarking and reporting of building annual energy use intensity.
  • Annual 2.5 percent improvement in energy use intensity every year through the end of 2015.
  • All new buildings be designed to achieve net-zero energy use beginning in 2020.

Good Practice in Action

At the end of the day, the success of building codes in producing the cost-savings, weather-resiliency, and energy efficiency is determined by how they are adopted and enforced locally. If the most current codes were universally adopted and enforced,

Photos: Atlas Roofing Corp.

there would be no competitive advantage to inferior building construction practices. Incremental upgrades would provide a steady stream of work that would increase competitiveness for building professionals and suppliers. Updated job skills would increase market value for construction professionals and enable innovation in the construction sector and increased market share for innovative products and processes that would improve economies of scale and lower their cost differential.

Building codes provide a comprehensive and reliable standard that contribute to local economies and improve building performance. Knowledge of code requirements help designers and contractors deliver more value to their clients. Finally, a bit more of an investment during design and construction can yield significant savings in building operation and tangible benefits to the environment and economy of areas that adopt higher building standards.

Roofing in Romania, Part II: Past as Prologue

[Editor’s Note: In May, Thomas W. Hutchinson presented a paper at the 2017 International Conference on Building Envelope Systems and Technologies (ICBEST) in Istanbul, Turkey, as did his good friend, Dr. Ana-Maria Dabija. After the conference, Hutchinson delivered a lecture to the architectural students at the University of Architecture in Bucharest, Romania, and spent several days touring Romania, exploring the country’s historic buildings and new architecture. Convinced that readers in the United States would appreciate information on how other countries treat roofing, he asked Dr. Dabija to report on roof systems in Romania. The first article, “Roofing in Romania: Lessons From the Past,” was published in the July/August issue of Roofing. In this follow-up article, Dr. Dabija continues her exploration of the forces shaping the architecture of Romania.]

A late 19th or early 20th century residential building in Bucharest. Photo: Ana-Maria Dabija.

(Photo 1) A late 19th or early 20th century residential building in Bucharest. Photo: Ana-Maria Dabija.

In buildings as well as in other fields of activity, there are at least three determinant factors in the choice of products:

  1. The technology. A key driving force is the technology that improves a product or system. Some systems are not at all new—the ones that use solar power, for instance—but are periodically forgotten and rediscovered; this is another story. The history of past performance is important here as well, as is the skill of the contractors installing the material or system. Technological advancements can mark important developments in industry, but the field is littered with “new and improved” products that never panned out, failed and are out of the market.
  2. The economy. The state of the economy is directly related to the state of the technology; better efficiency in the use of a type of resource leads to the use of more of that resource, as well as to a change of human behavior that adapts to the specific use of the resource. This dynamic is referred to as “the Jevons paradox” or “the rebound effect.” In a nutshell, William Stanley Jevons observed, in his 1865 book “The Coal Question,” that improvements in the way fuel is used increased the overall quantity of the utilized fuel: “It is a confusion of ideas to suppose that the economical use of fuel is equivalent to diminished consumption. The very contrary is the truth.” On the other hand, it seems that innovation is mainly accomplished in periods of crisis, as a crisis obliges one to re-evaluate what one has and to make the best of it.
  3. The political will. As one of the great contemporary architects, Ludwig Mies van der Rohe, stated, “Architecture is the will of the epoch translated into space.”

Like many other things, buildings can be read from the perspective of these factors. And so we go back to square one: history.

(Photo 2) Palace of the National Bank of Romania (1883-1900), designed by architects Cassien Bernard, Albert Galleron, Grigore Cerkez, and Constantin Băicoianu. Photo: Ana-Maria Dabija.

Our excursion in the history of the roofing systems in Romania moves from the 19th century to the present. As mentioned in the previous article, the use of metal sheets and tiles began sometime in the late 17th century (although lead hydro-insulation seems to have been used in the famous Hanging Gardens of Babylon in the sixth or seventh century, B.C.).

The Industrial Revolution that spread from the late 18th to the mid 19th century included the development of iron production processes, thus leading to the flourishing of a new range of building materials: the roofing products. The surfaces that can be covered with metal elements—tiles or sheets—span from low slopes to vertical. More complicated roofs appeared, sometimes combining different systems: pitched or curved roofs use tiles while low slopes are covered with flat sheets.

Copper, painted or galvanized common metal, zinc or other alloys cut in tiles and sheets, with different shapes or fixings—the metal roofs of the old buildings are a gift to us, from a generation that valued details more than we do, today (Photo 1).

(Photo 3) The Palace of the School of Architecture in Bucharest, designed by architect Grigore Cerchez. Photo: Ana-Maria Dabija.

In the second half of the 19th century, in 1859, two of the historic Romanian provinces—Walachia and Moldova—united under the rule of a single reigning monarch, and, in 1866, a German prince, Karl, from the family of Hohenzollern, became king of the United Principalities. In 1877 the War of Independence set us free from the Turkish Empire and led to the birth of the new kingdom of Romania. The new political situation led to the need of developing administrative institutions as well as cultural institutions, which—in their turn—needed representative buildings to host them. In only a few decades these buildings rose in all the important cities throughout the country.

The influence of the French architecture style is very strong in this period as, in the beginning, architects that worked in Romania were either educated in Paris or came from there. It is the case with the Palace of the National Bank of Romania (Photo 2), designed by two French architects and two Romanian ones.

(Photo 4) A detail of the inner courtyard and roof at the Central School by architect Ion Mincu, 1890. Photo: Ana-Maria Dabija.

The end of the 19th century is marked by the Art Nouveau movement throughout the whole world, with particular features in architecture revealing themselves in different European countries. In Romania, the style reinterprets the features of the architecture of the late 1600s, thus being called (how else?) the Neo-Romanian style. A few fabulous examples of this period that can be seen in Bucharest include the Palace of the School of Architecture (Photo 3), the Central School (Photo 4), the City Hall (Photo 5). Most of the roofs of this period use either clay tiles or metal tiles and metal sheets (Photos 6 and 7).

In parallel with the rise of the Art Nouveau style in Europe, the United States created the Chicago School, mainly in relation to high-rise office buildings. This movement was reinterpreted in the international Modernist period (between the two World Wars).

As a consequence of the Romanian participation in the First World War, in 1918 Basarabia (today a part of the Republic of Moldova, the previous Soviet state of Moldova), Bucovina (today partly in Ukraine) and Transylvania were united with Romania. The state was called Greater Romania. The capital city was Bucharest. Residential buildings as well as administrative buildings spread on both sides of the grand boulevards of the thirties, built in a genuine Romanian Modernist style (Photo 8).

(Photo 5) Bucharest City Hall, by architect Petre Antonescu 1906-1910. Photo Joe Mabel, Creative Commons Attribution.

Influences from the Chicago School are present in the roof types. Flat roofs began to be used, sometimes even provided with roof gardens (although none have survived to our day). It is probable that the hydro-insulation was a “layer cake” of melted bitumen, asphalt fabric and asphalt board, everything topped with a protection against UV and IR radiation. The “recipe” was mostly preserved and used until the mid-90s.

In the second half of the 20th century, the most common roofs were the bitumen membranes, installed layer after layer. Residential buildings and most administrative buildings had flat roofs. Still, in the center of the cities, more elaborate architecture was designed, so next to a church with a metallic roof, you might find a residential block of flats with pitched roofs covered with metal tiles, behind which the lofts are used as apartments (Photo 9).

Most of the urban mass dwellings, however, were provided with flat roofs (Photo 10). Even the famous House of the People (Photo 11)—the world’s second-largest building after the Pentagon—has flat roofs with the hydro-insulation made of bitumen (fabric and board layers).

(Photo 6) Residential buildings built in the late 19th or early 20th century in the center of Bucharest. Photo: Ana-Maria Dabija.

Corrugated steel boards or fiberboards were mainly used in industrial buildings and sometimes in village dwellings, replacing the wooden shingles as a roofing solution that could be easily installed (Photo 12).

After 1989, when the communist block collapsed, products from all over the world entered the market. The residential segment of the market exploded, as wealthy people wanted to own houses and not apartments. Pitched roofs became an interesting option, and the conversion of the loft in living spaces was also promoted. Corrugated steel panels, with traditional or vivid colors, invaded the roofs, serving as a rapid solution both for new and older buildings that needed to be refurbished. Skylights, solar tunnels and solar panels also found their way onto the traditional roofs as the new developments continued (Photo 13).

Today the building design market is mainly divided between the residential market and the office-retail market. Where roofs are concerned, unlike the period that ended in 1989 (with a vast majority of buildings with flat roofs, insulated with bitumen layers), most individual dwellings and collective dwellings with a small number of floors (3-4) are provided with pitched roofs, mainly covered with corrugated steel panels.

(Photo 7) The Minovici Villa, architect Cristofi Cerchez, 1913. Photo: Camil Iamandescu, Creative Commons Attribution.

For the high-rise buildings, the bitumen membranes (APP as well as SBS) are still the most common option, but during the past decade, elastomeric polyurethane and vinyl coatings have also been installed, with varying degrees of success. EPDM membranes, more expensive than the modified bitumen ones, are used on a smaller scale. PVC membranes have also been a choice for architects, as in the case of the “Henry Coandă” Internațional Airport in Bucharest. Bitumen shingles also cover the McDonalds buildings and other steep-slope roofs. In the last few years, green roofs became more interesting so, more such solutions are beginning to grow on our buildings.

The roof is not only the system that protects a building against weathering; today it is an important support for devices that save or produce energy. It will always be the fifth façade of the building, and it will always represent a water leakage-sensitive component of the envelope that should be dealt with professionally and responsibly. To end the article with a witty irony, the great American architect Frank Lloyd Wright is supposed to have said, “If the roof doesn’t leak, the architect hasn’t been creative enough.”

(Photo 8) The Magheru Boulevard in Bucharest. Photo: Ana-Maria Dabija.

(Photo 9) Apartment buildings of the late 20th century in Bucharest. Photo: Ana-Maria Dabija

(Photo 10) Mass dwelling building of the mid-1980s. Photo: Ana-Maria Dabija.

(Photo 11) The House of the People (today the House of the Parliament) is still unfinished. The main architect is Anca Petrescu. Photo: Mihai Petre, Creative Commons Attricbution CC BY-SA 3.0.

(Photo 12) Corrugated fiberboard on a traditional house in the Northern part of Romania. Photo: Alexandru Stan.

(Photo 13) The roof of the historic building of the Palace of the School of Architecture, with skylights, sun tunnels and BIPV panels. Photo: Silviu Gheorghe.

How Can Roofing Contractors Protect Themselves if a Project Gets Delayed?

Project delays can have serious financial consequences for both contractors and subcontractors. When such issues arise, one option for affected contractors is asserting delay claims to recover losses. Delay claims, however, must meet several criteria to survive in court, and claimants can pursue them in many different ways. This article will discuss different types of delay claims and the methods for asserting them, as well as what subcontractors can do to protect themselves the next time they encounter a project that is behind schedule.

In simple terms, a delay claim arises when a project is delayed and a contractor or subcontractor needs more time (and possibly more equipment and labor) than originally budgeted to fulfill its contractual obligation.

A delay claim can help a contractor extend an original deadline for completing a job or compensate it for the additional costs associated with the delay, which may include the overtime and additional manpower necessary to keep a job on schedule, as well as consequential damages like lost profits, lost opportunities, and home office and administrative costs.

Some delays, of course, cannot be avoided and do not qualify the impacted contractors for compensation. Examples include weather-related delays and delays arising from foreseeable circumstances. Although, when an owner or general contractor causes or is responsible for a preventable delay—also known as an inexcusable delay—the lower-tier contractor may recover the additional costs to complete the project. Some examples of inexcusable delays include the customer not having the job site ready on time, supplying defective materials to its contractor, giving its contractor insufficient access to the job site, or wrongly interfering with the project schedule.

Before committing to the complicated and risky delay claim process, most subcontractors should seriously consider resolving delay disputes either through informal means or, if applicable, through the “equitable adjustment” clauses within their contracts. Pursuing equitable adjustments can be less confrontational than pursuing delay claims. What equitable adjustment clauses allow varies from contract to contract, and parties are entitled negotiate contract terms to define what constitutes such an adjustment. Generally, however, an equitable adjustment is an adjustment in the contract price to reflect an increase in cost arising from a change in the completion date or duration of time for the contracted scope of work. These price adjustments typically encompass overhead and profit as well as actual costs. (In contrast, a change in the actual scope of work is typically addressed via an additive or deductive change order.)

Some jurisdictions that lack a legal definition of “equitable adjustment” will enforce the parties’ contract terms and, in the absence of evidence to the contrary, an equitable adjustment can simply mean cost, plus reasonable overhead and profit. For example, a recent North Carolina Court of Appeals decision (Southern Seeding Service Inc. v. W.C. English Inc., et al) involved a contract provision stating that unit prices were based upon the project being completed on schedule and that should the contractor’s work be delayed without its fault, “unit prices herein quoted shall be equitably adjusted to compensate us for increased cost… .”

Although neither the contract nor North Carolina law defined the term “equitable adjustment,” the court considered the parties’ intended definitions of the term. Both parties testified that essentially, “equitable adjustment” meant the difference in cost. The court allowed the claimant, Southern Seeding Service, to recover the difference in its actual per-unit costs and the per-unit costs in its bid, plus overhead and profit.

This decision indicates that even in the absence of a contract specifically stating otherwise, contractors can sometimes use equitable adjustment clauses to recover their cost increases resulting from delays. In the case of Southern Seeding, where a “no damage for delay” clause barred Southern Seeding from making a formal delay claim, this proved valuable. One downside to the approach, however, is that it does not necessarily compel upper-tier contractors or owners to speedily compensate contractors for delays. And, unlike some delay clauses, equitable adjustment clauses do not provide for interest accruing on properly noticed claims that go unpaid. Informal methods and equitable adjustments may prove more effective for contractors who have stronger and more positive relationships.

If equitable adjustment claims will not resolve delay issues, delay claims can help—given the right circumstances. One of the biggest hurdles to establishing delay claims is first giving proper notice to the upper-tier contractor or owner. Often, contracts contain notice provisions that restrict the time window in which contractors may present delay claims. For example, some contracts require contractors to submit their claims within a certain number of days—often, as few as two days—of the date that a delaying event occurs or is known to the contractor. Courts generally enforce notice provisions strictly, though there are exceptions.

Additionally, many contracts contain “no damage for delay” clauses that can eliminate delay claims entirely. Under such terms, courts have ruled contractors may only acquire extra time “in the owner’s discretion” and cannot receive damages unless the defending party has clearly breached the contract.

Courts in most jurisdictions recognize some exceptions to “no damage for delay” clauses, particularly when owners or upper-tier contractors deal in bad faith, unreasonably refuse to provide additional time, or unreasonably interfere with the claimants’ work.

Calculating Damages

Even if a delay claim is allowed by contract, selecting the proper method of measuring and reporting damages from a delay is essential to success. The two primary methods for calculating delay claims are the critical path method and the total cost method.

The critical path method is an analysis of a project’s schedule, which shows the length of a delay and how that delay disrupted the sequence of dependent tasks required to complete a project as scheduled. Ideally, actual records of project hours, materials, and other expenses, as well as agreed-upon schedules, can enable contractors to piece together the contemporary cost of a delay. Although most courts strongly prefer these actual records to calculate damages, contractors without schedule information may also attempt the critical path method by relying on scheduling experts who can retroactively reconstruct the project’s as-built schedule and testify on critical path items to estimate how much the delay impacted them.

If there is no way to collect the information sufficient for the critical path method, the total cost method might be an option for potential claimants. This approach calculates delay damages by subtracting the total anticipated costs of a project from its total actual costs. To use this method, contractors must show (1) the customer is completely at fault for the increased costs from a delay; (2) there are no other ways to measure the damages; and (3) both the bid and actual costs are reasonably calculated.

All three of these points can be difficult to prove, and most courts, regardless of jurisdiction, treat them with a great deal of scrutiny. The New Hampshire Superior Court for Merrimack County, for instance, in the case Axenics Inc. v. Turner Construction Co., wrote “the total cost method is a ‘theory of last resort.’”

One reason why some contractors gravitate towards the total cost method is that it does not require a full account of actual costs, and many contractors can easily calculate the losses themselves. The method also allows them to potentially recover lost profits. An additional approach to the total cost method is the modified total cost method, where contractors use the same formula as the total cost method but adjust it for bidding inaccuracies and/or performance inefficiencies to make their delay claims appear more accurate. The methods using actual costs, though, generally provide stronger evidence for damages, and most courts will only accept the total cost method if a contractor is able to prove there is no other way to account for the actual costs.

Many contractors who hope to recover home office expenses in delay claims use what is known as the Eichleay formula to determine such damages. Like other aspects of delay claims, however, the effectiveness of this method depends on the circumstances of the claim, a contractor’s documentation, and the jurisdiction. Furthermore, more conservative estimates may have greater chances of success. At its core, the Eichleay formula determines the amount of home office damages by multiplying the number of delay days by the average daily rate of home office overhead attributable the delayed contract. This daily overhead rate is calculated by dividing the delayed project’s share of a contractor’s total billings and dividing it by the number of days in the delayed contract (both the on-schedule and delay days). For cases involving government contracts, federal courts have deemed Eichleay claims as “the only proper method” for calculating home office damages provided they meet certain requirements. These requirements are: (1) the government caused the delay; (2) the period of delay was uncertain and the government required the contractor to be ready to resume its work on short notice; and (3) the contractor was unable to seek other work to cover its office expenses during that period.

Outside of matters involving federal contracts, courts treat Eichleay claims with a higher level of scrutiny than critical path claims. In an effort to discredit delay claims, defending parties often claim (correctly) that the Eichleay formula is only an estimate and not necessarily an accurate indicator of damages. To ensure the numbers within the calculation are true, contractors will likely have to provide audited financial statements—information smaller contractors may not be able to provide. Also, Eichleay damages may decrease if many of the office overhead costs were from bidding for the contract or if a contractor already paid most of its office expense before a delay late in a project. Although the federal government prefers the Eichleay formula, some state courts do not accept it and instead use the terms of a contract to determine the costs of overhead. Still, many contractors try to use the Eichleay formula whenever possible because it can potentially yield hundreds of thousands more in recovered expenses than other methods. Ultimately, the jurisdiction of a delay claim is a strong factor for deciding whether or not to use the Eichleay formula.

When project delays are inevitable, contractors have options to recover at least some of their losses. For many contractors, pursuing equitable adjustments will prove to be the most cost-effective and least adversarial solution. Companies that maintain detailed schedule records and give adequate, timely written notice of their delay concerns may successfully assert delay claims to avoid serious harm when a customer refuses to accommodate them (if contract provisions allow). Ultimately, consulting with a lawyer or delay consultant early in the delay process is the best protection from losing a legitimate claim.

Author’s Note

This article is not intended to give, and should not be relied upon for, legal advice. No action should be taken in reliance upon the information contained in this article without obtaining the advice of an attorney.

Understanding and Installing Insulated Metal Panels

IMP installation

IMP installation typically occurs once the steel frame is in place. The more common vertical installation allows for faster close-in for interior trade work. Photos: Metl-Span

Insulated metal panels, or IMPs, incorporate a composite design with foam insulation sandwiched between a metal face and liner. IMPs form an all-in-one-system, with a single component serving as the exterior rainscreen, air and moisture barrier, and thermal insulation. Panels can be installed vertically or horizontally, are ideal for all climates, and can be coated with a number of high-performance coating systems that offer minimal maintenance and dynamic aesthetic options.

The Benefits of IMPs

At the crux of the IMP system is thermal performance in the form of polyurethane insulation. Panel thicknesses generally range from 2 to 6 inches, with the widest panels often reserved for cold storage or food processing applications. IMPs provide roughly three times the insulation value of field-assembled glass fiber systems, and panel thickness and coating options can be tailored to meet most R-value requirements.

IMPs offer a sealed interior panel face to create a continuous weather barrier, and the materials used are not conducive to water retention. Metal—typically galvanized steel, stainless steel or aluminum—coupled with closed-cell insulation creates an envelope solution impervious to vapor diffusion. Closed-cell insulation has a much denser and more compact structure than most other insulation materials creating an advantage in air and vapor barrier designs.

Time, budget and design can all be looming expectations for any building project. A valuable characteristic of IMPs is their ability to keep you on time and on budget while providing design flexibility to meet even the toughest building codes. The unique single-source composition of insulated metal panels allows for a single team to accomplish quick and complete enclosure of the building so interior trades can begin. This expedites the timeline and streamlines the budget by eliminating the need for additional teams to complete the exterior envelope and insulation.

Minimizing Moisture

The seams function both as barrier and pressure-equalized joint, providing long-term protection that requires minimal maintenance. Multiple component systems often rely on the accurate and consistent placement of sealant and may also require periodic maintenance. In addition, with IMPS a vented horizontal joint is designed for pressure equalization, and, even in the presence of an imperfect air barrier, the pressure-equalized joinery maintains the system’s performance integrity. With multi component systems, imperfections can lead to moisture infiltration.

The real damage occurs when water enters through a wall and into a building becoming entrapped—which leads to corrosion, mold, rot, or delaminating. Unlike IMPs, some multi-component wall systems include a variety of different assembly materials that may hold water, like glass fiber or paper-faced gypsum. When those materials get wet, they can retain water, which can result in mold and degradation.

Installation

Typically, IMP installation is handled by crews of 2-4 people. Very little equipment is needed other than standard construction tools including hand drills, band and circular saws, sealant guns, and other materials. The panels can be installed via the ground or from a lift, and materials can be staged on interior floors or on the ground level. Panel installation typically occurs once the steel frame is in place and prior to interior fit out. The more common vertical installation allows for faster close-in for interior trade work.

Metl-Span CFR insulated metal standing seam roof panels

Metl-Span CFR insulated metal standing seam roof panels combine durable interior and exterior faces with exceptional thermal performance. Photos: Metl-Span

IMPs are often installed using concealed clips and fasteners that are attached to the structural supports (16 gauge minimum wall thickness tubes or stud framing). The panels are typically installed bottom to top and left to right, directly over the steel framing. No exterior gypsum or weather barriers are required, as these panels act as the building’s weather barriers.

The product’s high strength-to-weight ratio allows for longer installation spans and reduced structural costs. The metal skins act as the flange of a beam, resisting bending stress, while the foam core acts as the web of the beam, resisting shear stress. This important aspect also contributes to a long product life cycle.

Design Flexibility

IMPs offer a unique combination of aesthetic design options, including mitered panel edges, and a vast array of profiles, textures and reveal configurations. Flat wall profiles are ideally suited for designers seeking a monolithic architectural façade without sacrificing performance elements. The beautiful, flush panels have become a mainstay in projects in a number of high-end architectural markets.

The 35,000-square-foot AgroChem manufacturing facility in Saratoga Springs, N.Y.

The 35,000-square-foot AgroChem manufacturing facility in Saratoga Springs, N.Y., showcases vertically installed Metl-Span CF36 insulated metal panels. Photos: Metl-Span

Striated or ribbed wall profiles are more common in commercial and industrial applications. The products offer bold vertical lines for a distinctive blend of modern and utilitarian design, while continuing flawless symmetry from facade to facade, or room to room on exposed interior faces. Ribbed panels also work in tandem with natural lighting to create impactful designs. Different textures, such as embossed or simulated stucco finish, add dimensional nuance and contrast to projects of all shapes and sizes.

IMPs are offered in an unlimited palette of standard and custom colors to meet any aesthetic requirement, as well as energy-efficient solar reflectivity standards. Panels are typically painted with a polyvinylidene fluoride (PVDF) coating with optional pearlescent and metallic effects, and can even simulate expensive wood grains and natural metals. PVDF finishes offer exceptional performance characteristics that can be tailored to meet most any project needs, including saltwater environments and extreme weather conditions.

Roof Configurations

For all the above reasons, IMPs have also become a popular building product for roofing applications. Insulated metal standing seam roof panels provide the desired aesthetic of traditional single-skin metal standing seem roofs with added thermal performance. Standing seam roof panels feature a raised lip at the panel joinery, which not only enhances overall weather resistance but provides the desired clean, sleek sightlines.

IMP installation

IMP installation typically occurs once the steel frame is in place. The more common vertical installation allows for faster close-in for interior trade work Photos: Metl-Span

The systems typically feature field-seamed, concealed fasteners that are not exposed to the elements. Just like their wall panel counterparts, insulated metal standing seam roof panels are available in a variety of thicknesses and exterior finishes.

Another popular insulated metal roof application showcases overlapping profile panels. The product’s overlapping, through-fastened joinery allows for quick installation in roof applications, resulting in reduced labor costs and faster close-in.

Finally, insulated metal roof deck panel systems combine the standard steel deck, insulation, and substrate necessary for single-ply membranes or non-structural standing seam roof coverings. The multi-faceted advantages of this system include longer spans between supports, superior deflection resistance, and a working platform during installation.

Insulated metal wall and roof panels offer an exceptional level of value when compared to traditional multi-component wall systems. The product’s unique single-component construction combines outstanding performance with simple and quick installation, a diverse array of aesthetic options, and the quality assurance of a single provider.

Roofing in Romania: Lessons From the Past

[Editor’s Note: In May, Thomas W. Hutchinson presented a paper at the 2017 International Conference on Building Envelope Systems and Technologies (ICBEST) in Istanbul, Turkey, as did his good friend, Dr. Ana-Maria Dabija. After the conference, Hutchinson delivered a lecture to the architectural students at the University of Architecture in Bucharest, Romania, and spent several days touring Romania, exploring the country’s historic buildings and new architecture. Convinced that readers in the United States would appreciate information on how other countries treat roofing, he asked Dr. Dabija to report on roof systems in Romania in the first of what is hoped to be a series of articles on roofing in foreign countries.]

Photo 1. Sanctuary in Sarmizegetusa Regia. Photo: Oroles. Public Domain.

Photo 1. Sanctuary in Sarmizegetusa Regia. Photo: Oroles. Public Domain.

Romania is somewhere in the Southeastern part of Europe, in a stunning landscape: an almost round-shaped country, with a crown of mountains—Carpathians—that close the Transylvanian highlands, with rivers that flow towards the plains, that merge into the Danube and flow to the Black Sea.

Conquered by the Romans in 106 A.D, crossed by the migrators between the fourth and the eighth centuries, split in three historic provinces—Walachia, Moldova and Transylvania—and squeezed between empires, Romania absorbed features from all the people and civilizations that passed through or stayed in its territories.

The language—Latin in its structure—has ancient Dacian words that blend in with words from languages from other countries that had influence in our history: Greek, French, Turkish, English, Slavonic, Serbian, German, Hungarian. Traditional foods vary by region; for instance, in Transylvania you won’t find fish, while at the seaside, in the Danube Delta, on the banks of the rivers, fish is traditional. Each historic province uses different ingredients and developed recipes that can be found in Austria and Hungary, in Greece and Turkey, in Russia and Ukraine.

The same applies to buildings. In Transylvania, the Austrian Empire hallmarked the houses in the villages, the mansions, the palaces, the churches, the administrative buildings. One of the most popular sites for foreign tourists is the Bran Castle, infamous home of Dracula. In Walachia, the buildings have strong Balkan influences. Close to the Black Sea, the Turkish and the Greek communities that settled there brought the style of the countries they came from. Moldova was under the influence of the Russian Empire reaching back to Peter the Great.

Photo 2. Densuș church, Hațeg County, has a roof made of stone plates. Photo: Alexandru Baboș, Creative Common Attribution.

Photo 2. Densuș church, Hațeg County, has a roof made of stone plates. Photo: Alexandru Baboș, Creative Common Attribution.

Romania is situated in the Northern hemisphere, about halfway between the Equator and the North Pole. The climate features hot, dry summers with temperatures that can rise to 113 degrees Fahrenheit in the South, and cold winters, with temperatures that can drop to minus 22 degrees in the depressions of Transylvania, with heavy snow and strong winds. There are some spots with milder temperatures, close to the sea and in the western part of the country.

Why all this introduction? Because specific geographic conditions lead to specific building systems. People living in areas with abundant rain and snow need materials and systems that resist and shed water; after all, the steeper the slope, the faster the water is evacuated off the roof.

Cultural influences color the patrimony, but climatic conditions define the geometry and the materials that are used for roofs. As there are different climatic conditions as well as diverse cultural influences, the building typologies of the roofs are, in their turn, diverse.

Ancient Settlements

Photo 3. Below-ground cottage in the Village Museum in Bucharest. Photo: Ana-Maria Dabija.

Photo 3. Below-ground cottage in the Village Museum in Bucharest. Photo: Ana-Maria Dabija.

Although these territories were inhabited for millennia, the roofs did not “travel” in time as long as the walls. The six ancient citadels of the Dacians, located almost in the center of Romania in the southwestern side of the Transylvanian highlands, still preserve ruins of the limestone, andesite or wooden columns of the shrines, altars, palaces and agoras. No roofs survived. (See Photo 1.) We can only presume that the materials that were used for the roofing were wood shingles or thatch, which would explain both why artefacts of the roofs could not be found and also why the deterioration is so advanced.

After Rome conquered Dacia, emperor Trajanus built a citadel that was supposed to represent continuity with the previous civilization: the Sarmizegetusa Ulpia Traiana. It seems to have had an active life, considering the temples, palaces and dwellings that we inherited, including an amphitheater for 5,000 people. Still, no roofing traces survived.

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Definition of Resilience: Hospital Provides a Lesson in Preparing for Weather Events

Staten Island University Hospital escaped major damage during Hurricane Sandy. The city of New York allocated $28 million to fund the hospital’s resiliency plan, and the state contributed an additional $12 million.

Staten Island University Hospital escaped major damage during Hurricane Sandy. The city of New York allocated $28 million to fund the hospital’s resiliency plan, and the state contributed an additional $12 million.

Almost five years ago, Hurricane Sandy bore down on New York City with winds that reached gusts of 100 miles an hour and a storm surge 16 feet above normal that flooded huge parts of the city. Entire neighborhoods lost electricity for several days, the Stock Exchange closed during and immediately after the storm, and scuba divers were called in to assess damage in parts of the city’s submerged subway system.

Staten Island, one of New York’s five boroughs, was heavily damaged. Its position in New York Harbor, at the intersection of the coastlines of Long Island and New Jersey, leaves the island particularly exposed to storm surge during extreme weather events. A geologist from Woods Hole Oceanographic Institution in Massachusetts described Staten Island as being, “at the end of, basically, a big funnel between New Jersey and New York.”

Staten Island University Hospital almost miraculously escaped major damage, despite flood waters coming within inches of it doors. The hospital stayed open during and after Hurricane Sandy, continuing to provide vital services despite the storm. The hospital is home to the largest emergency room on Staten Island, and houses more than one third of the borough’s in-patient beds. New York Mayor DeBlasio has called the hospital, “a truly decisive healthcare facility—even more so in times of crisis.”

While both hospital and city officials were relieved that the facility had escaped Sandy largely unharmed, the lesson that Sandy delivered was taken to heart: major mitigation efforts were needed if the hospital expected to survive similar storms in the future. With this in mind, the city of New York allocated $28 million to fund the hospital’s resiliency plan, with the state kicking in an additional $12 million.

The money is being spent on three major projects to better prepare the hospital for future storms: the elevation of critical building power and mechanical systems, the installation of sanitary holding tanks and backflow prevention, and the installation of major wind resiliency and roofing improvements. 

Resilient Design

The Staten Island experience, and the plan to upgrade its ability to withstand major weather events, is hardly unique. Nationwide, resilient design has become a major focus of the construction community.

Hurricane Sandy certainly intensified the sense of urgency surrounding the need for resilience. But well before that, Hurricane Katrina, in 2005, provided a tragic case study on the fragility of seemingly stable structures, as the storm brought a small, poor southern city to the brink of chaos and devastated entire neighborhoods. While these two hurricanes drew national and international attention, communities throughout the country have also been dealing with frequent, erratic and intense weather events that disrupted daily life, resulting in economic losses and, all too often, the loss of human life. These emergencies may include catastrophic natural disasters, such as hurricanes, earthquakes, sinkholes, fires, floods, tornadoes, hailstorms, and volcanic activity. They also refer to man-made events such as acts of terrorism, release of radioactive materials or other toxic waste, wildfires and hazardous material spills.

The focus, to a certain degree, is on upgrading structures that have been damaged in natural disasters. But even more, architects and building owners are focusing on building resilience into the fabric of a structure to mitigate the impact of future devastating weather events. And, as with the Staten Island Hospital, the roof is getting new attention as an important component of a truly resilient structure.

The resilience of the roofing system is a critical component in helping a building withstand a storm and rebound quickly. In addition, a robust roofing system can help maintain a habitable temperature in a building in case of loss of power. Photo: Hutchinson Design Group.

The resilience of the roofing system is a critical component in helping a building withstand a storm and rebound quickly. In addition, a robust roofing system can help maintain a habitable temperature in a building in case of loss of power. Photo: Hutchinson Design Group.

So, what is resilience, how is it defined, and why is it important to buildings in differing climates facing unique weather events? The Department of Homeland Security defines resilience as “the ability to adapt to changing conditions and withstand and rapidly recover from disruption due to emergencies.” The key words here are “adapt” and “rapidly recover.” In other words, resilience is measured in a structure’s ability to quickly return to normal after a damaging event. And the resilience of the roofing system, an essential element in protecting the integrity of a building, is a critical component in rebounding quickly. In addition, a robust roofing system can provide a critical evacuation path in an emergency, and can help maintain a habitable temperature in a building in case of loss of power.

According to a Resilience Task Force convened by the EPDM Roofing Association (ERA), two factors determine the resiliency of a roofing system: durable components and a robust design. Durable components are characterized by:
Outstanding weathering characteristics in all climates (UV resistance, and the ability to withstand extreme heat and cold).

  • Ease of maintenance and repair.
  • Excellent impact resistance.
  • Ability to withstand moderate movement cycles without fatigue.
  • Good fire resistance (low combustibility) and basic chemical resistance.
  • A robust design that will enhance the resiliency of a roofing system should incorporate:

  • Redundancy in the form of a backup system and/or waterproofing layer.
  • The ability to resist extreme weather events, climate change or change in building use.
  • Excellent wind uplift resistance, but most importantly multiple cycling to the limits of its adhesion.
  • Easily repaired with common tools and readily accessible materials.
  • More Information on Resilient Roofing

    The Resilience Task Force, working with the ERA staff, is also responding to the heightened interest in and concern over the resilience of the built environment by launching EpdmTheResilientRoof.org. The new website adds context to the information about EPDM products by providing a clearinghouse of sources about resilience, as well as an up-to-date roster of recent articles, blog posts, statements of professional organizations and other pertinent information about resilience.

    “This new website takes our commitment to the construction industry and to our customers to a new level. Our mission is to provide up-to-date science-based information about our products. Resilience is an emerging need, and we want to be the go-to source for architects, specifiers, building owners and contractors who want to ensure that their construction can withstand extreme events,” said Mike DuCharme, Chairman of ERA.

    EPDM roofs can be easily repaired and restored without the use of sophisticated, complicated equipment. Photo: Hutchinson Design Group.

    EPDM roofs can be easily repaired and restored without the use of sophisticated, complicated equipment. Photo: Hutchinson Design Group.

    EPDM and Resiliency

    The Resilience Task Force also conducted extensive fact finding to itemize the specific attributes of EPDM membrane that make it a uniquely valuable component of a resilient of a roofing system:

  • EPDM is a thermoset material with an inherit ability to recover and return to its original shape and performance after a severe weather event.
  • EPDM has been used in numerous projects in various geographic areas from the hottest climate in the Middle East to the freezing temperatures in Antarctica and Siberia.
  • After decades of exposures to extreme environmental conditions, EPDM membrane continues to exhibit a great ability to retain the physical properties and performances of ASTM specification standards.
  • EPDM is the only commercially available membrane that performs in an unreinforced state, making it very forgiving to large amounts of movement without damage and potentially more cycles before fatiguing.
  • EPDM offers excellent impact resistance to hail, particularly when aged.
  • EPDM is resistant to extreme UV exposure and heat.
  • EPDM far exceeded the test protocol ASTM D573 which requires materials to pass four weeks at 240 degrees Fahrenheit. EPDM black or white membranes passed 68 weeks at these high temperatures.
  • Exposed EPDM roof systems have been in service now for 50-plus years with little or no surface degradation.
  • EPDM is versatile.
  • EPDM can be configured in many roofing assemblies, including below-grade and between-slab applications.
  • EPDM is compatible with a broad range of construction materials/interfaces/conditions, making it a good choice for areas that may encounter unique challenges.
  • EPDM can be exposed to moisture and intense sunlight or totally immersed in salty water.
  • EPDM can easily be installed, repaired and restored following simple procedures without the use of sophisticated, complicated equipment.
  • EPDM can be repaired during power outages.
  • For further information about the need for resilience, and the appropriate use of EPDM in resilient structures, visit EPDMTheResilientRoof.com.