The drive for environmentally-friendly products extends to the commercial construction arena, including roofing systems. In this post, we will discuss some of the energy aspects of roofing: reflectivity, emissivity, and the solar reflectance index.

Environmental Impact – Part B

Rooftop reflectivity has received substantial attention during 2009, perhaps most notably in Energy Secretary Steven Chu’s remarks recommending that the world’s roofs be painted white. The upshot is that a roofing material’s ability to reflect solar energy has environmental implications, including its contribution to (or mitigation of) the urban heat island effect and impact on emerging carbon markets, among others. In fact, a roofing system’s energy efficiency is really determined by a couple of interrelated attributes.

Reflectivity (technically, albedo) is the percentage of solar energy reflected by a surface. The higher the reflectance value, the more solar energy that will be reflected from the surface.

Emissivity is the measure of how effectively a material sheds the heat it has absorbed. Materials with a high emissivity value may absorb energy easily, but they also radiate large amounts of it back into the atmosphere.

Roofing systems that provide both high reflectivity and emissivity are most likely to have a significant impact on a building’s energy cost. Some systems can reduce a building’s energy consumption by up to 40%.

The solar reflectance index (SRI) is a tool that evaluates reflectivity, emissivity, and other factors to determine a roof’s overall ability to reject solar heat. Its calculation is defines by ASTM E 1980-01 and is based on a formula that includes values for solar absorptance, solar flux, emissivity, the Stefan Boltxman constant, and other coefficients.

Standard black (reflectivity 5%, emissivity 90%) has an index of 0, and standard white (reflectivity 80%, emissivity 90%) has an index of 100. Very “hot” materials can actually have negative values and very “cool” materials can have values greater than 100. Materials with the highest SRIs are the coolest choices for roofing.

The Duro-Last Cool Zone® roofing system, a PVC membrane, has initial reflectivity and emissivity measurements of 87.5% and 95%, respectively, and a resulting SRI value of 108.

Here are the SRIs of some other roofing materials as measured by Lawrence Berkeley Labs and the Florida Solar Energy Center:

There are many associations that roofing manufacturers, contractors, and other industry professionals can be involved with. Some are technical and engineering-oriented; others are sales and networking associations; and some deal with each of these aspects in the roofing and construction industries.

This is the fifth in a series of posts that will discuss the various associations that benefit roofing manufacturers, contractors, and other industry professionals.

ORNL

The Oak Ridge National Laboratory (ORNL) is a multi-program science and technology laboratory managed for the U.S. Department of Energy by UT-Battelle, LLC. Scientists and engineers at ORNL conduct basic and applied research and development to create scientific knowledge and technological solutions that strengthen the nation’s leadership in key areas of science; increase the availability of clean, abundant energy; to restore and protect the environment; and contribute to national security.

The ORNL has also completed in-depth research studies on the reflectivity of PVC roofing systems, and is currently studying vegetative systems along with collecting field data on the corrosion factors that affect ACQ treated lumber.

RCI

RCI, Incorporated (RCI) is an international association of professional consultants, architects, and engineers who specialize in the specification and design of roofing, waterproofing, and exterior wall systems.

Since 1983, RCI members have offered design, repair planning, quality observance, legal testimony, and general roof management services. The 2006 inclusion of waterproofing and exterior walls in its mission and service scope reflects the understanding that roofing issues often influence the entire building envelope. Increasingly, RCI members are called upon to address building-wide concerns from below-grade to rooftop.

RICOWI

The Roofing Industry Committee of Weather Issues, Inc. (RICOWI) was established in 1990 as a nonprofit organization to identify and address important technical issues related to the cause of wind damage.

In 1996, RICOWI was incorporated as a nonprofit corporation devoted to research and education on wind issues. After reviewing the need for similar education and research in the areas of hail, energy-efficiency, and durability effects, the organization’s objectives were broadened in 1999 to include other weather topics, and “Wind” in RICOWI’s name was changed to “Weather” to reflect the expanded scope. RICOWI is assisted by the Oak Ridge National Laboratory.

Single-Ply Cool Roofing Systems

Many single-ply roofing systems have become popular in commercial applications due to their long-term performance, easy maintenance, and life-cycle cost benefits. Some of them have emerged as the best long-term cool roofing options. Their common attribute: high reflectivity.

• Polyvinyl chloride (PVC) single-ply roofing systems have the best track record of long-term performance among white single-ply cool roofing systems. The first white PVC systems were installed in Germany during the 1960s, and their overall performance and life cycle cost benefits made these early systems popular in Europe during the 1970s and ‘80s.

• Chlorosulfonated polyethylene (CSPE) single-plies were the earliest widespread white roofing systems in the U.S., introduced in the 1970s under the Hypalon® brand. Although effective as a cool roofing system, Hypalon has not achieved the same commercial success as PVC, EPDM and other single-plies.

• More recent cool roofing single-ply developments include the introduction of thermoplastic polyolefins (TPOs) and certain new co-polymer alloys (CPAs) during the late 1980s and 1990s.

Today, many single-ply roofing systems are available in white, including EPDM and modified bitumen, but PVC and TPO systems are the most popular and best-performing in terms of long-term reflectance. The National Roofing Contractors Association (NRCA) has identified the PVC/TPO thermoplastic single-ply category as the fastest growing roofing sector in America for several years. The coolest among these systems typically have solar reflectance ranging from 70 percent to 85 percent.

Installing a single-ply cool roofing system can save energy and money for building owners all over the United States.

The Cool Roof Rating Council was created to develop accurate and credible methods for evaluating and labeling the solar reflectance and thermal emittance of roofing products. The CRRC’s web site enables you to search for rated products as you investigate roofing systems that will help make your building as energy-efficient as possible.

In our final installment we will discuss Regulatory Incentives and Mandates.

You must consider many factors when your roof needs to be replaced or when you are constructing a building that requires a new roof. Reviewing these factors will help you to make the wisest roofing choice and get the best long-term value for your investment.

There’s a lot to cover in a discussion of the environmental issues surrounding roofing selections, so we’re dividing it up into two posts.

Environmental Impact – Part A

Today’s society calls for more products that are environmentally-friendly, and that drive extends to commercial construction products, including roofing systems. Several factors have a bearing on a system’s environmental impact.

When researching roofing systems, investigate the materials that are used in their production. During the past several years, PVC building materials have been scrutinized perhaps more than any other, largely due to production issues that date back more than 30 years. In fact, a recent USGBC report indicated that on the whole, PVC is as benign as other construction products, and in some cases may be the most environmentally-friendly option.

Many PVC single-ply membranes are also lightweight and can often be installed over existing roofing systems, eliminating costly and landfilling tear-offs and requiring less fuel to transport to the job site than other heavier materials.

Some roofing systems benefit not only the external environment, but the internal environment as well, contributing to better indoor air quality and occupant comfort. With optimized insulation and venting, some systems can also relieve positive air pressure to keep indoor air cleaner.

When researching roofing systems, learn what happens to manufacturing scrap as well as the system itself after the end of its useful life. Some roofing manufacturers recycle scrap into other commercial products like flooring, expansion joints, walkpads, etc. Furthermore, manufacturers like Duro-Last® have implemented recycling programs for PVC roof membranes after their useful roofing lives. Such programs keep waste out of landfills and reduce the need for virgin feedstock used in a number of construction products, including new roofing membranes.

In our next installment of Factors To Consider When Purchasing A Roofing System, we will discuss the energy aspects of roofing: reflectivity, emissivity, and the solar reflectance index.

Statement:  “PVC building products create poisonous gasses when they burn.”

The facts: This is technically a true statement, but misleading, because it is true about all organic materials (containing carbon), whether natural or synthetic, and there are countless organic materials in every commercial building. The major gaseous products of the combustion of PVC are carbon monoxide, carbon dioxide, hydrogen chloride and water. Chlorine gas is never produced when PVC burns.

But unlike other building materials, PVC is resistant to ignition; most rigid and flexible PVC will not burn without the continued application of heat from another source. The temperature required to ignite PVC is more than 300ºF (150ºC) higher than that required to ignite wood. The potential for flame to spread from burning PVC is very low because it has a slow rate of heat release, and it does not drip when it burns; instead, it develops a char which inhibits the spread of flame.

When it comes to structural fires, the U.S. Green Building Council’s Technical and Scientific Advisory Committee (TSAC), in its February 2007 report, Assessment of the Technical Basis for a PVC-Related Materials Credit for LEED, admits that there are many sources of toxic gases besides PVC. The report advises that “any firefighter not using a breathing apparatus would be taking on unnecessary risk, regardless of the specific materials present.” There is evidence that – as do many other building materials – PVC may contribute to hazardous conditions in building fires. However, there is insufficient information to determine how widespread or consistent the risks are. The TSAC report goes on to say that “compared with other plastics, and other combustible materials, PVC may have a beneficial role in reducing injuries in structural fires, as it may reduce the chances of a fire igniting or spreading due to its relatively high ignition temperature.”

Below is a video of how three roofing membranes burn when exposed to direct flame.

In our final installment, we’ll look at this statement: “PVC is the largest source of dioxin, the most poisonous chemical on earth.”

Darrell Morris - Mid-Atlantic Regional Sales Coordinator

Darrell Morris has been with Duro-Last® for nearly15 years with the last five as the Mid-Atlantic Regional Sales Coordinator.  Darrell works out of the corporate headquarters in Saginaw, MI. He is responsible for supporting the sales representatives and roofing contractors in his area, which includes Virginia, West Virginia, as well as portions of Pennsylvania, and New York.

Prior to his current position, Darrell started at Duro-Last in production as a shipping clerk. Darrell then worked as a cost accountant/inventory control clerk before becoming a customer sales representative where he assisted customers with their orders and general roofing questions.

Darrell credits his success at Duro-Last to his training in the military. Darrell was active in the Army, Army Reserves, and the National Guard for almost 20 years before he was given a medical honorable discharge. During this time, Darrell served in Operation Just Cause, Operation Desert Storm as well as provided security at the 1996 Olympics in Atlanta, Georgia.

Darrell enjoys the relationships he has built over the years with his sales reps and roofing contractors. “I enjoy traveling to the Mid-Atlantic area and spending time with the different people in my territory,” said Darrell.

One common theme that all employees mention is the family atmosphere. Duro-Last has and always will portray the feeling that you are one of the family.

You must consider many factors when your roof needs to be replaced or when you are constructing a building that requires a new roof: Price. Quality of the product being installed. Prefabrication. Installation disruptions. Ease of maintenance. Performance. Environmental impact. Life-cycle costs, and so on. It is crucial to review all of these aspects in order to make the wisest roofing choice and get the best long-term value for your investment.

This is the sixth post in a series discussing the issues involved in purchasing a roofing system.

Proven Track Record

How long has the roofing system you are considering been on the market? How has it performed? Has its formula changed over the years to improve performance? Is “thicker” really “better” when it comes to roof performance? Answers to these questions are vital to know in order to get the best roof for your building.

Hundreds of roofing systems are on the market today, and sometimes they seem to blend together and appear to offer the same qualities. Not true. Look at how long the roofing product has been around and then evaluate its success. Most manufacturers will be happy to direct you to satisfied customers who can describe how their roofing system solved a problem.

Thicker=Better? Not So Fast!

Some roofing manufacturers promote the idea that when it comes to roof performance, “thicker” means “better.” However, that is not necessarily the case.

Some manufacturers increase membrane thickness by adding more material to the bottom film layer but little to the exposed layer. However, increasing bottom layer thickness does not directly increase membrane performance. Rather, performance is a balance between film formulation, membrane thickness, and reinforcement.

Film formulation determines the flexibility of the membrane and its ability to resist crazing and cracking over time, plus protect against ultraviolet (UV) radiation.

Membrane thickness provides protection from water, snow, and ice elements.

Reinforcement provided by the scrim layer of the membrane is the source of the membrane’s strength. The scrim protects against natural elements such as wind and hail, and from human activities that can cause punctures and tears. Additionally, reinforcement gives dimensional stability to the membrane and strength against building movement.

If you buy or specify single-ply roofing systems, your decision should be based on membrane performance, not thickness alone.

In our seventh installment in this series, we will discuss roofing system features that have a positive impact on the environment.

Significant Savings Drive Demand for Cool Roofing

Cool Roofing Options and Choosing the Best Cool Roofing System

There are two primary types of cool roofing products on the market today: (1) reflective paints and coatings; and (2) single-ply roofing systems. Paints and coatings based on either acrylic or elastomeric chemistry can be an effective short-term solution for reducing energy costs, but most facility owners looking for long-term, low-maintenance solutions opt for a complete single-ply roofing system.

Many roofing products are on the market, which can make choosing the right one a challenge. Fortunately, several objective tools are available to help with the process. Choosing a system from the approved list of products in the EPA’s ENERGY STAR® Roof Products Program or from the Cool Roof Rating Council (CRRC) ratings chart is a good way to narrow down the selection process. Products on the ENERGY STAR list undergo rigorous testing before approval to ensure that they meet the established standard for reflectance.

In addition, the ENERGY STAR Roof Products Program has developed an energy savings calculator that projects the potential savings from installing a cool roof compared with alternative “non-cool” systems.

Here is a short list of important factors to consider when selecting a cool roofing system:

1. Reflectance/emittance performance, both initial and after three years.
2. Long-term track record of durability and performance.
3. A good warranty backed by a solid, well-established manufacturer.
4. Climate and weather extremes in a given location.
5. Maintenance requirements and ease of repair.

In our next installment we will discuss: Single-Ply Cool Roofing Systems

There are many associations that roofing manufacturers, contractors and other industry professionals can be involved with. Some are technical and engineering-oriented; others are sales and networking associations; and some deal with each of these aspects in the roofing and construction industries.

This is the fourth in a series of posts that discuss associations related to the roofing industry.

LBL

The Lawrence Berkeley National Laboratory (LBL or Berkeley Lab) was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

The Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines.

Berkeley Lab developments have resulted in billions of dollars in savings for lighting, windows, and other energy-efficient technologies such as roofing systems.

The lab provides a wide variety of research that is relevant to “cool” roofs and the urban heat island effect, giving building owners important information they can use to select the right roofing system for their building.

NRCA

Established in 1886, the National Roofing Contractors Association (NRCA) is one of the construction industry’s oldest trade associations and a voice for professional roofing contractors worldwide.

The NRCA offers roofing industry information for roofing professionals, including technical information, special reports, insurance and safety information, and the latest industry news.

The NRCA also provides a wide range of information and services to help home owners and building owners make informed decisions about replacing and maintaining their roofing systems.

NRLRC

Established in 1979 by the NRCA as a separately funded organization, the National Roofing Legal Resource Center (NRLRC) acts as a legal advocate for roofing contractors throughout the United States.

Issues such as contract language, employee relations, regulatory compliance, payment provisions, insurance coverage, and codes and standards can threaten a company’s profitability and even its existence. The NRLRC provides contractors with assistance in resolving such legal issues, ultimately saving them time and attorneys’ fees.

Screening A Contractor

Before hiring a contractor, a building owner should ask several questions:

• Can the contractor provide references from satisfied customers?
• What experience does he or she have with similar installations?
• What is their experience with the product being installed?

Many manufacturers have implemented a quality rating system to ensure that the contractors installing their roofing systems are proficient. Duro-Last’s Master and Elite Contractor programs are intended to give building owners/facility managers confidence that the roofing system will be installed to high-quality standards.

“To qualify for these Duro-Last programs, a contractor must have installed our roofing system on a variety of buildings, and achieved consistently high-quality inspection scores over several years,” said Mitch Guettler, Quality Assurance Manager at Duro-Last.

The building owner should also verify that the contractor’s business is financially stable. Before allowing any business to become one of its authorized roofing contractors, some manufacturers obtain a credit report from Dun & Bradstreet (D & B), noted Tom Allen, President of Allen Consulting Group, Inc. When the contractor’s business is so new that there isn’t a D & B report on file, the manufacturer may ask to see his or her banking history. To be sure, each contractor sets different parameters regarding the information he or she is willing to provide to potential business partners.

“Most of the better contractors have appropriate financial statements that they’re willing to make available,” added Allen.

What A Contractor Should Provide:

• Qualified employees.
• Equipment that will enable the completion of the project at hand.
  • Vehicles that can haul away refuse at the end of each day.
  • Safety equipment such as guard rails and fall protection harnesses for employees to use while completing a roofing installaion.

Another crucial factor to consider when selecting a roofing contractor is their employees’ experience and skills levels.

“What drives installation quality today is the experience of the foreman or job superintendent,” said Allen. “It’s critical that the building owner or facility manager ask the contractor how much experience the employees have installing different types of roofing.”

Additionally, the building owner/facility manager and contractor will also want to go over variables that will help ensure a smooth-running project.

Points of discussion should include:

• The location of a staging area for tools and materials.
• Expected duration of the installation and what (if any) building disruptions can be expected.
• Daily work hours.
• A number to call if problems occur outside of normal business hours.

Finally, the building owner should ask the roofing contractor the following post-installation questions:

• How does the contractor plan to handle post-installation work?
• Will the contractor inspect the roof annually? If so, is there a fee?

The best solution is to have the contractor and building owner establish a yearly maintenance program together to help ensure the performance and longevity of the roofing system.

In our next installment, we will discuss who is responsible for what when it comes to the roofing system warranty.