RICOWI to Host Underlayment Seminar on March 17

The underlayment systems play a vital role in today’s roof designs for long-term performance. The challenges of selecting the right materials, application techniques and performance criteria can be challenging to the roofing professional. RICOWI‘s Spring Seminar, which will be held March 17, 2017, in Anaheim, Calif., will provide an in-depth look at the two styles of underlayments—organic and synthetic—that might be used in low- and steep-slope roof designs. This seminar will touch upon the product designs, product approvals and code language that address how to select and properly use these various underlayment products in roof system applications.

Underlayment Speakers
Organic Underlayment: Doug Thagard, Fontana Paper Mills
Synthetic Underlayment: Mark Strait, Synthetic Roof Underlayment Institute

When underlayments are installed as part of a roof system, they may have special requirements for how they are designed, selected and installed to meet the anticipated roof performance. To better understand the relationship of the components, the speakers will cover the various styles of roof applications that will help inform the audience of best practices from the various industry associations.

Association Speakers
Low-slope Underlayment Applications: Mike Ennis, SPRI
Steep-slope Underlayment Applications:

For more information, visit RICOWI’s website or contact Joan Cook, executive director, at (330) 671-4569.

Research Helps Industry Organizations Conclude Ballasted Roofs Provide Energy Savings

During the last decade, the roofing industry has been increasingly impacted by two strong forces: first, rising energy prices with no real end in sight, and, second, increasingly stringent building codes and regulations, designed to limit emissions, reduce energy use and mitigate the impact of urban heat islands.

The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007.

The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007. PHOTO: EPDM Roofing Association

The industry response has also been two-fold: In some instances, new products have been created, such as lower VOC adhesives, primers and sealants, self-adhering membranes and a wider variety of reflective membranes. At the same time, roofing professionals have taken a close look at some of the products that have been in use for a generation. Using rigorous science, they have tested these tried-and-true products to see how they measure up against the new standards. And in many cases, they’ve found that products that have been in use for decades are delivering great results in this new, energy-sensitive environment. Case in point: ballasted roofing, which has been available since the early 1970s, is turning out to be a great choice to meet 21st century needs.

2007 Study

The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007. Andre Desjarlais, ORNL’s group leader of Building Envelope Research, and his colleagues had just completed work in which “we had done a fairly substantial comparison of different cool roof technologies, both membrane types, as well as coatings,” Desjarlais says. At the request of EPDM manufacturers, working together at the newly founded EPDM Roofing Association (ERA), Bethesda, Md., as well as manufacturers within Waltham, Mass.-based SPRI, Desjarlais designed and implemented a second study to assess the performance of ballasted roofing. “We undertook a study to effectively expand what we had done earlier on coatings and membranes,” he says.

Other factors also encouraged ORNL to generate data about ballasted roofing. The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings. Desjarlais believed this definition of a “cool roof” might be inaccurately limiting roofing choice by excluding other roofing materials, such as ballasted roofs, that would deliver comparable savings.

The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings.

The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings. PHOTO: EPDM Roofing Association

In addition, in Chicago, a new Chicago Energy Code was adopted as early as 2001 “with high reflectivity and emissivity requirements that limited severely building owners’ and managers’ roof system choices”, according to a paper presented in 2011 by Bill McHugh of the Chicago Roofing Contractors Association. At the roofing industry’s request, a reprieve was granted, giving the industry until 2009 to come up with products with a reflectivity of 0.25.

Faced with that 2009 deadline, the Chicagoland Roofing Council, Chicago Roofing Contractors Association and Rosemont, Ill.-based National Roofing Contractors Association began in 2001 to conduct research on products that would help to meet the city’s goal of creating a workable Urban Heat Island Effect Ordinance while giving building owners a wider choice of roofing products. As part of their effort, the industry coalition turned its attention to the energy-saving qualities of ballasted roofing and coordinated its work with the research at ORNL.

Desjarlais points out the concept of thermal mass having energy benefits has been accepted for years and has been a part of the early version of ASHRAE 90.1. “Thermally massive walls have a lower insulation requirement, so there was industry acceptance of the fact that using mass is a way of saving energy,” he says. “But we had a hard time translating that understanding from a wall to a roof. Whether you do that with a concrete block or a bunch of rocks doesn’t really matter. The metric is no different. Roofs or walls.”

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SPRI Bulletin Addresses Code Evaluations for Roofing Products

Waltham, Mass.-based SPRI’s latest informational Bulletin (No. 1-15) updates building code officials, specifiers, building owners and others on code evaluations and product approval requirements for roofing products. The bulletin centers on the requirements of the international codes as they relate to membrane roof covering systems. SPRI represents sheet membrane and component suppliers to the commercial roofing industry.

The bulletin is designed to update building code officials and members of the International Code Council (ICC) on the various ways roofing manufacturers can provide evidence of code compliance. The bulletin considers products that are referenced in the code, as well as new and innovative roofing products and assemblies. The SPRI Bulletin zeroes in on some practical options available to the building official or Authority Having Jurisdiction (AHJ).

In Bulletin No. 1-15, SPRI points out that Research Reports are not mandatory for single-ply roofing membranes that comply with standards referenced in the codes. Research Reports from approved sources are intended to assist in the approval of materials or assemblies not specifically provided for in the code. Therefore, the AHJ should not insist on a Research Report for a membrane roof system if the manufacturer has data available for the AHJ to review.

“Code officials are increasingly asking for a Research Report from single-ply roofing manufacturers to demonstrate code compliance,” says SPRI member Michael Beaton of Intertek, a global provider of product certification and performance-testing services. “While a research report should not be mandated since these products and systems are described in the code with specific requirements and referenced standards, a Research Report is an easy way for the manufacturer to provide the necessary information to the code official.

“SPRI’s ultimate goal in publishing Bulletin 1-15 is two-fold,” Beaton continues. “First, that code officials understand that a Research Report is a ‘convenience’ for single-ply roofing and should not be required if other relevant data is available. Second, that when the roofing manufacturer does choose to document compliance in a Research Report, code officials should be willing to accept a Research Report from an agency other than ICC Evaluation Service, provided the agency is accredited for this activity.”

SPRI Bulletin No. 1-15 is two-pages long and available for free viewing and download.

SPRI Revises Wind Design Standard Practice for Roofing Assemblies for Inclusion in the International Building Code

SPRI has revised ANSI/SPRI WD-1, Wind Design Standard Practice for Roofing Assemblies, to prepare the document for submission to and inclusion into the International Building Code (IBC). SPRI represents sheet membrane and component suppliers to the commercial roofing industry.

This Wind Design Standard Practice provides general building design considerations, as well as a methodology for selecting an appropriate roofing system assembly to meet the rooftop design wind uplift pressures calculated in accordance with ASCE 7, Minimum Design Loads for Buildings and Other Structures.

“Revisions to ANSI/SPRI WD-1 include additional insulation fastening patterns, along with more detailed practical examples,” says Task Force Chairman Joe Malpezzi. “This Standard Practice is appropriate for non-ballasted Built-Up, Modified Bitumen, and Single-Ply roofing system assemblies installed over any type of roof deck.”

In addition, SPRI has revised and reaffirmed ANSI/SPRI RD-1, Performance Standard for Retrofit Drains, in compliance with ANSI’s five-year cycle requirements. This standard is a reference for those that design, specify or install retrofit roof drains designed for installation in existing drain plumbing on existing roofs.

“It is important to note that the RD-1 Standard addresses the design of retrofit primary drains,” says SPRI President Stan Choiniere. “Local codes may also require secondary or overflow drains. SPRI will also be revisiting this standard after upcoming code changes are released.”

For more information about these standards and to download a copy, visit SPRI’s Web site or contact the association.

Are You ‘PV Ready’?

Commercial rooftops are an attractive platform for the installation of solar photovoltaic (PV) electricity-producing systems. These low-slope roofs offer an economical and sustainable structural foundation for renewable solar energy. As an example, one of the largest roof-mounted PV systems in North Carolina has been online for several months at the Old Dominion Freight Line Inc. vault logistics facility in Thomasville. Almost 7,700 solar panels completely cover the warehouse’s 160,000-square-foot roof and produce enough power (1.8 megawatts) to offset more than 90 percent of the building’s annual energy costs.

Success stories like Old Dominion’s are becoming increasingly common in the sunny Carolinas. However, it is important to remember a roof’s function is, first and foremost, to protect the building’s contents and people from the elements. In this regard, roofing professionals need to anticipate the potential risks associated with the installation of a roof-mounted PV system (array). This sort of due diligence is particularly important when installing PV systems on existing warranted roofs.

A broad selection of membranes and thicknesses are available for consideration when a PV installation is planned. Photo courtesy of GAF, Wayne, N.J., and Protech Roofing Service, San Diego

A broad selection of membranes and thicknesses are available for consideration when a PV installation is planned. Photo courtesy of GAF, Wayne, N.J., and Protech Roofing Service, San Diego

To help in these industry efforts, members of Waltham, Mass.-based SPRI—the trade association that represents sheet membrane and component suppliers to the commercial roofing industry—have developed “PV Ready” roof assemblies and guidelines designed to provide maximum protection for the roof (and maintain its warranty coverage).

In September, SPRI’s technical committee and board of directors also approved and distributed to its members Technical Bulletin 1-13A, “Summary of SPRI Membrane Manufacturer Photovoltaic (PV) Ready Roof Systems and Services”. The bulletin contains general guidelines from SPRI related to “PV Ready” roof assemblies. This article goes into more depth about issues related to PV installations, particularly on existing warranted roofs.

Ask the Right Questions

The installation of a PV system on an existing warranted roof raises many important questions for the roofing professional and building owner. For example, will the roof accommodate the added weight of the PV array? Logistically speaking, before property owners decide on a solar-power system, they will need to determine whether their roofs are sturdy enough to support
the additional loads put on the existing roof structure by the solar array.

An average solar panel and support system typically add a minimum of 3 to 4 pounds per square foot to the existing roof. It is the responsibility of the roofing professional to ensure this additional weight does not exceed the load limits determined by the building’s designer.

From an economic (life-cycle-cost) point of view, it makes sense the service life of the existing roof membrane will come close to matching the projected service life of the PV system. If not, a complex and costly reroofing project may be required long before the solar panels need to be replaced. In general, the underlying roofing system must provide the same minimum investment horizon—generally at least 25 years—to realize the full potential of the rooftop PV system.

Most PV arrays require penetrating the roof membrane. Even non-rack-type systems may include electrical conduits, wiring and other components that may need to be flashed in a professional manner. It is essential the responsibility for this flashing work rests with the roofing contractor.

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SPRI Distributes ‘PV Ready’ Technical Bulletin

Waltham, Mass.-based SPRI’s Technical Committee and board of directors have approved and distributed to the organization’s members Technical Bulletin 1-13A, “Summary of SPRI Membrane Manufacturer Photovoltaic (PV) Ready Roof Systems and Services”. The bulletin contains general guidelines from SPRI related to “PV Ready” roof assemblies and services designed to provide maximum protection for the roof (and maintain its warranty coverage). SPRI represents sheet membrane and component suppliers to the commercial roofing industry.

“Commercial rooftops are a convenient platform for installing solar photovoltaic systems,” says SPRI Technical Director Mike Ennis. “However, it’s important to remember that the roof’s primary function is to protect the building’s contents and its people from the elements.”

Technical Bulletin 1-13 raises important considerations for the building owner, such as the added weight of a PV array and the impact of wind and fire approvals. The bulletin also lists potential PV system-specific requirements from manufacturers to maintain existing warranties; project documentation forms frequently required to install the PV system over an existing warranted roof; and general issues and additional services offered by manufacturers, such as single-source warranties for the roof system and solar integration.

SPRI gathered the information included in Technical Bulletin 1-13 from a survey of information available on websites and literature of SPRI member membrane manufacturers. As such, the bulletin serves as a summary of the PV-ready products, requirements and services currently offered by SPRI members and is available for distribution to customers.

“Each SPRI member may have its own PV ready program, and no SPRI member may necessarily be considered to have all program elements,” Ennis adds. “The building owner should always consult the manufacturer of the roof system specified for the new construction or reroofing project prior to the installation of a PV system on a warranted roof.”

In addition, Ennis writes about PV Ready rooftop considerations in “Tech Point”.