Learning and Trying New Things

The start of a new school year is always an exciting time. As I see my friends post photos on Facebook of their kids’ first days of school, I am reminded of the excitement I felt way back when. I loved wearing a new outfit, seeing friends I hadn’t seen in awhile and anticipating all the fun—and learning—in the year ahead. In a way, I get to recreate those feelings each time I put together a new issue of Roofing. I’m continually learning about the industry and this issue is no different.

For example, in “From the Hutchinson Files”, Thomas W. Hutchinson, AIA, FRCI, RRC, CSI, RRP, principal of Hutchinson Design Group, Barrington, Ill., and a Roofing editorial advisor, explains the virtues of cover boards. As he points out in his article, the use of cover boards can now be considered a good roofing practice.

Meanwhile, Jared O. Blum, president of the Polyisocyanurate Insulation Manufacturers Association, Bethesda, Md., explains a new white paper about polyisocyanurate insulation R-values in “Cool Roofing”. He states the R-value of polyiso roof insulation is reduced at some point at lower temperatures, but within any reasonable temperature range associated with typical building operating conditions in almost any climate in North America the difference appears to be very small.

In addition, we here at Roofing like to learn and try new things. As a result, this issue is interactive! Please download the free Layar Augmented Reality app, which was designed to bring print to life. Then hover over page 45 in the print edition with your smartphone or tablet to view a video about Virginia Polytechnic Institute and State University’s Indoor Practice Facility in Blacksburg, Va., which features almost 1,000 squares of 238-foot-long, curved, standing-seam metal panels. We’re really excited about this new capability and would love to know what you think.

White Paper Identifies Appropriate Mean Reference Temperature Ranges and R-values of Polyiso Roof Insulation within this Range

A number of recent articles have explored the relationship between temperature and R-value with an emphasis on the apparent reduction in R-value demonstrated by polyisocyanurate (or polyiso) roof insulation at cold temperatures. The science behind this apparent R-value decrease is relatively simple: All polyiso foam contains a blowing agent, which is a major component of the insulation performance provided by the polyiso foam. As temperatures decrease, all blowing agents will start to condense, and at some point this will result in a marginally reduced R-value. The point at which this occurs will vary to some extent for different polyiso foam products.

a mean reference temperature of 40 F is based on the average between a hot-side temperature of 60 F and a cold-side temperature of 20 F.

A mean reference temperature of 40 F is based on the average between a hot-side temperature of 60 F and a cold-side temperature of 20 F.

Because of this phenomenon, building researchers have attempted to determine whether the nominal R-value of polyiso insulation should be reduced in colder climates. Because of the obvious relationship between temperature and blowing-agent condensation, this certainly is a reasonable area of inquiry. However, before determining nominal R-value for polyiso in colder climates, it is critical to establish the appropriate temperature at which R-value testing should be conducted.

TO DETERMINE the appropriate temperature for R-value testing of polyiso, it is important to review how R-value is tested and measured. Figure 1 provides a simplified illustration of a “hot box” apparatus used to test and measure the R-value of almost all thermal-insulating materials. The insulation sample is placed within the box, and a temperature differential is maintained on opposing sides of the box. To generate accurate R-value information, the temperature differential between the opposing sides of the box must be relatively large—typically no less than 40 F according to current ASTM standards. The results of this type of test are then reported based on the average between these two temperature extremes, which is referred to as mean reference temperature. As shown in Figure 1, a mean reference temperature of 40 F is based on the average between a hot-side temperature of 60 F and a cold-side temperature of 20 F. In a similar manner, a mean reference temperature of 20 F is based on a hot-side temperature of 40 F and a cold-side temperature of 0 F.

NOW THAT we’ve had an opportunity to discuss the details of R-value testing, let’s apply the principles of the laboratory to the real-world situation of an actual building. Just like our laboratory hot box, buildings also have warm and cold sides. In cold climates, the warm side is located on the interior and the cold side is located on the exterior. If we assume that the interior is being heated to 68 F during the winter, what outdoor temperature will be required to obtain a mean reference temperature of 40 F or 20 F? Figure 2 provides a schematic analysis of the appropriate mean reference temperature.

As illustrated in Figure 2, the necessary outdoor temperature needed to attain a 40 F mean reference temperature would be 12 F while an outdoor temperature as low as -28 F would be needed to obtain a 20 F mean reference temperature. And herein lies a glaring problem with many of the articles published so far about the relationship between temperature and R-value. Although a 20 F or 40 F “reference temperature” may sound reasonable for measuring R-value, average real-world conditions required to obtain this reference temperature are only available in the most extreme cold climates in the world. With the exception of the northernmost parts of Canada and the Arctic, few locations experience an average winter temperature lower than 20 F.

schematic analysis of the appropriate mean reference temperature.

A Schematic analysis of the appropriate mean reference temperature.

To help illustrate the reality of average winter temperature in North America, a recent white paper published by the Bethesda, Md.-based Polyisocyanurate Insulation Manufacturers Association (PIMA), “Thermal Resistance and Temperature: A Report for Building Design Professionals”, which is available at Polyiso.org, identifies these average winter temperatures by climate zone using information from NOAA Historical Climatology studies. As shown in Table 1, page 2, the PIMA white paper identifies that actual average winter temperature varies from a low of 22 F in the coldest North American climate zone (ASHRAE Zone 7) to a high of 71 F in the warmest climate zone (ASHRAE Zone 1).

In addition to identifying a realistic winter outdoor average temperature for all major North American climate zones, Table 1 also identifies the appropriate mean reference temperature for each zone when a 68 F indoor design temperature is assumed. Rather than being as low as 40 F or even 20 F as sometimes inferred in previous articles, this mean winter reference temperature varies from a low of no less than 45 F in the coldest climate zone to above 50 F in the middle climate zones in North America.

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Insulfoam Introduces Branding for Full Line of EPS Insulation Products

To help design professionals, builders, homeowners and other customers more quickly find the insulation products they need, Insulfoam insulation offerings, including R-Tech insulations, are now categorized under the brand names InsulRoof, InsulWall and InsulGrade.

To help design professionals, builders, homeowners and other customers more quickly find the insulation products they need, Insulfoam insulation offerings, including R-Tech insulations, are now categorized under the brand names InsulRoof, InsulWall and InsulGrade.

Insulfoam, a manufacturer of block-molded expanded polystyrene (EPS), introduces branding for its full line of EPS insulation products. To help design professionals, builders, homeowners and other customers more quickly find the insulation products they need, Insulfoam insulation offerings, including R-Tech insulations, are now categorized under the brand names InsulRoof, InsulWall and InsulGrade.

“EPS is the only insulation you can use anywhere in the building envelope; at Insulfoam we offer specialized EPS products for use in roofs, walls, below grade and beyond,” says Ram Mayilvahanan, director of marketing for Insulfoam. “With such a huge product offering, this new branding helps our customers quickly find the right products to use among our numerous options. So, if you’re a roofer, you’ll look at the InsulRoof line to find your products, and don’t need to see InsulGrade below-grade options that aren’t applicable to current project needs.”

In conjunction with the new branding, Insulfoam has also revamped its website. The Insulfoam website now offers simple navigation to the major building categories: commercial and residential, with the InsulRoof, InsulWall and InsulGrade product groups clearly marked. The residential tab provides homeowners with home insulating tips for key areas, including energy saving tips for the house in basements and garage doors. Customers can also easily find on the new website Insulfoam’s other EPS offerings, including geofoam lightweight fill and EPS for cold storage buildings, flotation, packaging and architectural shapes.

Insulfoam EPS is 100 percent recyclable and offers a high R-Value per dollar. The features and benefits of InsulRoof, InsulWall and InsulGrade insulations are:

    InsulRoof

  • A wide range of faced, laminated and standard high-performance EPS insulation products for use on virtually any type of roof deck in new construction and reroofing applications.
  • Available in cost-saving applications including fanfold panel bundles, flute fill and tapered insulation.
  • Wide range of compressive strengths to help reduce insulation material costs.
  • Versatile to adapt to various roof shapes and roofing assemblies.
  • Products carry UL and FM labels.
    InsulWall

  • Full range of EPS insulation for use throughout walls, including cavity walls, on the interior faces of foundation walls, as exterior sheathing (including tongue-and-groove sheathing under stucco), gable ends, and as part of exterior insulation finishing systems (EIFS).
  • Insulfoam’s Total Wall System is one of the few insulated systems on the market that integrates weather resistant barrier (WRB).
  • Insulfoam EPS qualifies for several NFPA 285 compliant assemblies.
    InsulGrade

  • Full range of EPS products for use on foundation walls and under concrete floor slabs.
  • EPS outperforms extruded polystyrene (XPS) insulations in these applications due to EPS’s stable long-term R-value and moisture performance (it dries quickly and has minimal long-term moisture retention), and is lower cost.
  • Seven standard compressive strengths allow for more cost-effective specification without over-engineering the insulation under slabs.

Spray Polyurethane Foam: A Key Component to Any Net Zero Solution

SPF has the ability to insulate, air and water seal, as well as control moisture throughout the structure, acting as a single-source solution, reducing the need for multiple products.

SPF has the ability to insulate, air and water seal, as well as control moisture throughout the structure, acting as a single-source solution, reducing the need for multiple products.

In July 2014, California initiated the revision process to the 2016 version of Title 24, California’s building energy efficiency codes, which are designed to move the state’s residential and commercial buildings toward zero net energy (ZNE). All new residential construction is to be ZNE by 2020, and all new commercial buildings are to achieve ZNE by 2030. While aggressive, these goals are achievable with the right design implementation and accessibility to proper building materials.

As one of the world’s most influential economies, the state of California has demonstrated its power in leading the other 49 states in the implementation of progressive initiatives. California traditionally takes an environmental stance with a history of enforcing regulations designed to protect the physical environment and health of the state’s residents. These efforts often result in national trending with other states and municipalities following suit with similar regulations. It is widely anticipated a similar phenomenon will occur with ZNE goals.

The design of a ZNE building focuses on the reduction of energy consumption and on the generation of the structure’s own renewable energy (such as via solar panel solutions). Long-term ZNE begins with a quality building enclosure. High-performance attics and wall systems are a key focus of 2016 Title 24 as they make a significant impact in the reduction of peak cooling demand in structures.

SPF may be installed in a continuous layer, eliminating thermal bypasses, and boasts one of the highest R-values of all insulation options.

SPF may be installed in a continuous layer, eliminating thermal bypasses, and boasts one of the highest R-values of all insulation options.

Because of spray polyurethane foam’s unique attributes, the material is widely recognized as an optimal solution for unvented attics, as well as for roofing, walls and ceilings. SPF has the ability to insulate, air and water seal, as well as control moisture throughout the structure, acting as a single-source solution, reducing the need for multiple products.

Energy loss may occur at various points throughout the roof, walls and ceiling via air leakage. Thus the air-sealing ability of SPF is extremely beneficial when trying to improve energy efficiency.

In roofing, SPF acts as a protective roofing solution and as an insulator.

In roofing, SPF acts as a protective roofing solution and as an insulator.

As a thermal insulator, SPF forms in place and fully adheres, almost completely eliminating the cracks and gaps that allow escape of conditioned air. It may be installed in a continuous layer, eliminating thermal bypasses typically found with cavity insulations and boasts one of the highest R-values of all insulation options.

In roofing, SPF acts as a protective roofing solution and as an insulator. The effectiveness of insulation is measured through moisture control, air leakage, health, safety, durability, comfort and energy efficiency factors, and SPF scores exceptional marks in all.

These combined characteristics are integral to SPF’s ability to contribute to total ZNE solutions—solutions, which will become increasingly necessary as the net zero revolution takes hold across the U.S.

Energy-efficient Cool-roof Legislation: Creating Jobs and Reducing Energy Costs

Building on two roofing trends—higher thermal performance and cooler roofs in hotter climates—that have policymakers and architects seeing eye to eye, energy-efficient cool-roof legislation offers a significant opportunity to increase building energy efficiency and create jobs. Known in the last Congress in the Senate as S. 1575, the Energy-Efficient Cool Roof Jobs Act, and in the House of Representatives as H.R. 2962, the Roofing Efficiency Jobs Act, the legislation is scheduled to be reintroduced this spring.

The intent of the legislation is to encourage improvement in the thermal performance of existing roofs and, where appropriate in the designer’s judgment, encourage the use of a white or reflective roof surface in hotter climates. This is a clear win-win for the environment and building owners in terms of reduced energy costs and reduced pollution associated with energy consumption.

energy efficiency

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SIGNIFICANT SAVINGS lie within the commercial roofing sector, where more than 50 billion square feet of flat roofs are currently available for retrofit, 4 billion of which are typically retrofitted each year. The legislation would provide a 20-year depreciation period (instead of the current 39 years) for commercial roofs that meet minimum R-values that are significantly higher (requiring more insulation) than those required under state and local building codes and that have a white or other highly reflective surface. This change would correct an inequity in the current depreciation system (the average life span of a low-slope roof is only 17 years). By providing this incentive, the federal government would allow building owners and architects to decide whether the combination of thermal insulation and reflective roofs are appropriate for a given climate.

The required R-values under the proposed legislation are identical to the prescriptive requirements found under ASHRAE 189.1-2011, “Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings”. This legislation would be limited to retrofits of existing low-slope roofs and would not be available to new buildings. The cool roof requirement would only apply to buildings in ASHRAE Climate Zones 1 through 5, which covers approximately the area of the country from Chicago and Boston south. Roofs may qualify for the depreciation in zones 6, 7 and 8 but would not need a cool surface. View a map of the ASHRAE Climate Zones.

According to the U.S. Department of Energy’s Annual Energy Review, 2011, buildings account for 19 percent of the nation’s total energy usage and 34 percent of its electricity usage. Policies directed at commercial buildings are important to improving the economy, reducing pollution and strengthening energy efficiency. Although the country has over time maintained a steady pace in improving energy efficiency, a huge potential still exists, especially for commercial buildings. A wide range of credible estimates are available that point to this potential for cost-effective energy-efficiency improvements (see the graph).

THIS PROPOSED legislation complements the approaches taken in more comprehensive energy-efficiency proposals by focusing on the roof, which is the only building-envelope component that is regularly replaced but rarely upgraded to address energy and other environmental impacts.

Most buildings were constructed before building energy codes were first developed in the mid-1970s, or buildings were constructed under relatively weak codes, so these older, under-insulated roofs offer an important opportunity for increased energy savings. During the next 17 to 20 years, most of the weatherproof membranes on all commercial roofs will be replaced or recovered, which is the most cost-effective time to add needed insulation.

By accelerating demand for energy-efficient commercial roofs, the proposed legislation would:

    ▪▪ Create nearly 40,000 new jobs among roofing contractors and manufacturers.
    ▪▪ Add $1 billion in taxable annual revenue to the construction sector.
    ▪▪ Save $86 million in energy costs in the first year.
    ▪▪ Eliminate and offset carbon emissions by 1.2 million metric tons (equal to emissions of 229,000 cars).

THE LEGISLATION has the support of the Polyisocyanurate Insulation Manufacturers Association; National Roofing Contractors Association; Alliance to Save Energy; American Council for an Energy-Efficient Economy; Associated Buildings & Contractors Inc.; Building Owners and Managers Association International; United Union of Roofers, Waterproofers and Allied Workers; and several more construction industry associations.

When Sens. Cardin and Crapo reintroduce the Energy-Efficient Cool Roof Jobs Act, they hope it will influence the future debate about tax and energy policy. Although consideration of tax reform has stalled for the moment, when Congress returns to this issue it will be a golden opportunity to consider ideas for reforming cost-recovery periods and removing the disincentives that overly long depreciation schedules currently place on building energy-efficiency improvements.

Polyiso Roof Insulation R-value Update

An update to ASTM C1289, “Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation”, (ASTM C1289-13) features important improvements regarding the prediction of Long-Term Thermal Resistance (LTTR) for a variety of polyiso insulation roof boards. Members of the Polyisocyanurate Insulation Manufacturers Association (PIMA) began reporting LTTR values in accordance with ASTM C1289-13 on Jan. 1, 2014.

ASTM C1289

ASTM C1289 was first published in 1998. The standard is a series of physical property tests, including the measure of an insulation’s LTTR, conducted to ensure a polyiso product’s performance meets a minimum standard. The standard is used to predict an insulation’s R-value equivalent to the average performance of a permeably faced foam insulation product during 15 years.

To provide a comprehensive approach to predicting long-term R-value throughout North America, the updated ASTM C1289-13 standard incorporates two test methods: ASTM C1303-11 and CAN/ULC-S770-09. Each of these methods offers a similar approach to predicting the long-term thermal performance for foam insulation materials that exhibit air and blowing-agent diffusion or aging across time.

ASTM C1303, “Standard Test Method for Estimating the Long-Term Change in the Thermal Resistance of Unfaced Closed Cell Plastic Foams by Slicing and Scaling Under Controlled Laboratory Conditions”, is, in part, the result of a research project at Oak Ridge National Laboratory. The project was co-funded by the U.S. Environmental Protection Agency, U.S. Department of Energy, PIMA, NRCA and the Society of the Plastics Industry.

CAN/ULC S770 is the result of work in Canada. This method is also based on the same thin-slicing and accelerated aging concept as ASTM C1303 but it also accounts for the effect of permeable facings, or skins, on the LTTR of foam insulation in addition to a number of other factors. Considered to be a prescriptive way to perform ASTM C1303 (a more narrowly defined procedure within the bounds described in the ASTM standard), CAN/ULC S770 predicts what the foam’s R-value will be after a five-year aging period—the equivalent to a time-weighted thermal design R-value of 15 years.

Based on extensive research during the past five years, including bias and ruggedness testing, most researchers now agree ASTM C 1303 and CAN/ULC–S770 provide similar and consistent results predictive of actual aged performance.

LTTR and Polyiso

The polyiso industry uses the newly revised ASTM C1289-13 standard for determining the thermal insulation efficiency of permeably faced products. LTTR represents the most advanced scientific method to measure the long-term thermal resistance of foam insulation products using blowing agents.

The use of an LTTR value provides numerous advantages:

  • It provides a technically supported, more descriptive measure of the long-term thermal resistance of polyiso insulation.
  • The thin slices are taken from current production insulation samples. Prior methods used samples that were at least three-months old with some up to six-months old.
  • Determining an LTTR value is fairly rapid and, depending on a slice’s thickness, can produce an LTTR design value for 2-inch-thick polyiso insulation board in about 90 days.
  • A formula is used to determine the aging time period for a particular thickness of insulation, instead of using the same conditioning period for products of all thicknesses as was done in the past.
  • It applies to all foam insulation with blowing agents other than air and provides a better understanding of the thermal performance of foam.

PIMA QualityMark

The PIMA QualityMark certification program is a voluntary program that allows polyiso manufacturers to obtain independent, third-party certification for the LTTR values for ASTM C1289 Type II, Class 1 and Class 2 permeable-faced polyiso foam insulation produced with EPA-compliant blowing agents. Participating companies are required to include each of their manufacturing locations in the PIMA QualityMark certification program. Polyiso is the only insulation to be certified by this program for its LTTR value.

The PIMA QualityMark program began reporting LTTR values in accordance with ASTM C1289-13 on Jan. 1. To participate in PIMA’s QualityMark certification program, a Class 1 roof is suggested to have a design R-value of 5.7 per inch.

FM Global, one of the world’s largest independent commercial and industrial property insurance and risk-management organizations, is the PIMA QualityMark certification administrator. Polyiso insulation samples are randomly chosen from each plant of a participating manufacturer in accordance with the program’s guidelines. An accredited testing laboratory then establishes and certifies to FM Global the 15-year LTTR value in accordance with ASTM C1289-13.

National Building Code of Canada Adopts Updated Standard for Measuring LTTR of Polyiso Products

On Oct. 31, 2013, the National Building Code (NBC) of Canada adopted the most recent version of CAN/ULC-S704-11, the standard specification for polyiso in Canada, which references the test method CAN/ULC-S770-09 for determining the long-term thermal resistance (LTTR) of polyiso foam insulation. This adoption brings consistency to the test methods used for measuring LTTR in Canada and the U.S.

In the U.S., polyiso manufacturers use the ASTM C1289 standard (ASTM C1289 Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board) to predict the long-term thermal resistance R-value for a variety of polyiso insulation boards. ASTM C1289 includes the CAN/ULC-S770-09 and ASTM C1303-12, another test method used for LTTR.

“Since our members make and ship product in the United States and Canada, it is critical that polyiso insulation be subjected to the same criteria for measuring LTTR in both countries,” says Jared Blum, president PIMA. “We are pleased that the NBC in Canada has adopted CAN/ULC-S704-11 and CAN/ULC-S770-09 and that it is in harmony with ASTM C1289. Together these standards provide more data for predicting the long-term thermal performance of polyiso insulation and further enhances the validity of PIMA’s QualityMark program.”

The PIMA QualityMark program, the only third-party program for the certification of the thermal value of polyiso insulation, allows polyiso manufacturers to obtain independent, third-party certification for the LTTR values of their polyiso insulation products. Polyiso is the only insulation to be certified by this unique program for its LTTR value. The program was developed by PIMA and is administered by FM Global.

To participate in PIMA’s QualityMark certification program, a Class 1 roof is suggested to have a design R-value of 5.7 per inch. PIMA member manufacturers will publish updated R-values for their polyiso products later this year. Polyiso is unique in that the R-value increases with the thickness of the foam, so three inches of polyiso has a higher R-value per inch than two inches.

PIMA QualityMark Will Begin Reporting ASTM C1289-11 LTTR Values

The ASTM C1289 Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board (ASTM C1289-11) has been updated and features important improvements regarding the prediction of long-term thermal resistance value for a variety of polyiso insulation boards. The PIMA QualityMark program, the only third-party program for the certification of the thermal value of polyiso insulation, will begin reporting Long Term Thermal Resistance (LTTR) values in accordance with ASTM C1289-11 on Jan. 1, 2014.

The PIMA QualityMark certification program is a voluntary program that allows polyiso manufacturers to obtain independent, third-party certification for the LTTR values of their polyiso insulation products. Polyiso is the only insulation to be certified by this program for its LTTR value. The program was developed by Washington, D.C.-based PIMA and is administered by FM Global, Johnston, R.I.

To participate in PIMA’s QualityMark certification program, a Class 1 roof is suggested to have a design R-value of 5.7 per inch. PIMA member manufacturers will publish updated R-values for their polyiso products later this year. Polyiso is unique in that the R-value increases with the thickness of the foam, so 3 inches of polyiso has a higher R-value per inch than 2 inches.

“Since its founding, PIMA has been very active in the harmonization of relevant standards, including ASTM and CAN/ ULC, in an effort to provide greater continuity in the reporting of polyiso roof insulation thermal values throughout North America. That is why the association implemented the industry-wide Quality-Mark certified R-value program for rigid polyiso roof insulation in 2004,” says Jared Blum, president, PIMA. “The update to this standard provides more data to aid in the prediction of long-term thermal performance of polyiso insulation.”

To provide a comprehensive approach to predicting long-term R-value throughout North America, the updated ASTM C1289-11 standard now incorporates two test methods, ASTM C1303-11 and CAN/ULC-S770-09, which offer a similar approach to predicting the long-term thermal performance for foam insulation materials that exhibit air and blowing agent diffusion or aging over time. Both test methods employ a technique called “slicing and scaling” to accelerate this aging process and provide an accurate and consistent prediction of product R-value after five years, which is equivalent to a time-weighted thermal design R-value for 15 years. The update to ASTM C1289-11 in no way impacts polyiso’s physical properties.