Updated, third-party verified EPDs provide transparent, cradle-to-grave environmental impact data for polyiso roof insulation, polyiso wall insulation and HD polyiso roof cover boards.

The Polyisocyanurate Insulation Manufacturers Association (PIMA), the trade association representing North American manufacturers of polyiso insulation, announced the publication of updated Environmental Product Declarations (EPDs) for polyiso insulation products. The third-party verified and ISO-compliant EPDs provide industry-averaged environmental impact data for polyiso roof insulation, polyiso wall insulation and high-density (HD) polyiso roof cover board products manufactured by PIMA members in the United States and Canada.

What is an EPD?

An EPD is an internationally recognized document and reporting tool that discloses the environmental impacts of building materials like insulation to help inform building product selection. EPDs are developed using product category rules (PCRs) and are based on standardized life cycle assessments (LCAs) to ensure that architects, specifiers and sustainability professionals have access to accurate and credible product data.

A major milestone in sustainability and transparency reporting 

The publication of PIMA's updated EPDs marks another important milestone in the Association's long and demonstrated history of leadership on sustainability and transparency reporting.

"The publication of industry-averaged EPDs for polyiso products is no small feat and the participating manufacturers should be applauded for their participation and commitment to the project," said PIMA's senior director of technical affairs, Marcin Pazera, Ph.D. "Over the past two years, PIMA worked with participating manufacturers and outside LCA experts to collect, analyze and validate data submitted from facilities across North America. The end result is EPD reports that provide an accurate and comprehensive look at the impacts and advantages of polyiso products used throughout the construction sector."

What architects, specifiers and sustainability professionals need to know about PIMA's EPDs

PIMA's newly published EPDs for polyiso roof insulation, polyiso wall insulation and HD polyiso roof cover boards include several key features:

• Cradle-to-Grave LCA for polyiso: Reports environmental impacts across the full product life cycle, based on a 75-year building service life
• Product category rule compliance: Published in accordance with applicable PCRs for insulation and roof cover board products, including the recently updated and enhanced PCR for building thermal envelope insulation
• Scaling factors for accurate results: For polyiso roof and wall insulation products, the EPDs include scaling factors that allow professionals to calculate impacts based on specific insulation board thicknesses
• Roof replacement factor: For polyiso roof insulation and HD polyiso roof cover board, the EPDs consider the impacts of a full roof replacement during the 75-year building service life
• Industry-wide data coverage: Includes primary manufacturing data from 2023 for all participating PIMA member facilities
• Third-party verification: Independently verified and published in NSF's official EPD database to ensure confidence

Polyiso EPDs support sustainable building and certification

The updated polyiso EPDs provide industry-averaged data to enable informed material selection and contribute to the development of high-performance, sustainable buildings. These EPDs can also support compliance with green building programs such as LEED and other LCA-based certification frameworks.

"As the focus on the environmental impacts of buildings and building materials continues to increase, PIMA is well-positioned to engage and educate regulators and industry stakeholders on the life cycle benefits and environmental impacts of polyiso products, including polyiso roof insulation, polyiso wall insulation and high-density (HD) polyiso roof cover board," said PIMA president, Justin Koscher.

Download reports 

PIMA's most current EPDs for polyiso insulation products are now available for download at: https://www.polyiso.org/page/EPDs

About PIMA

The Polyisocyanurate Insulation Manufacturers Association (PIMA) serves as the voice of the rigid polyiso industry, proactively advocating for safe, cost-effective, sustainable and energy-efficient construction. Organized in 1987, PIMA is an association of polyiso manufacturers and industry suppliers. Polyiso is one of North America's most widely used and cost-effective insulation products. To learn more, visit www.polyiso.org.

insulation products. To learn more, visit www.polyiso.org.

The survey is an industrywide effort to collect information about the reroofing market spearheaded by a coalition of trade associations.

The National Roofing Contractors Association encourages roofing professionals to join industry trade associations representing contractors, consultants and manufacturers in the U.S. and Canada in taking part in the latest Quarterly Market Index Survey for Reroofing to evaluate business conditions during the first quarter of 2026.

For more than two years, the survey has taken the pulse of the reroofing industry and continues to serve as a regular barometer of the industry’s business conditions. By asking a handful of business questions and measuring responses across several demographics, the survey helps indicate the reroofing market’s strength and trajectory. Your response provides valuable insight.

The results of the Quarterly Market Index Survey for Reroofing are made available to all survey participants via an online dashboard that enables users to filter results by region and other metrics.

For the previous survey that measured business activity during the fourth quarter of 2025, 75% of responses came from roofing contractors and 25% came from roof consultants.

The survey is an industrywide effort to collect information about the reroofing market spearheaded by a coalition of trade associations, including the Asphalt Roofing Manufacturers Association, Canadian Roofing Contractors Association, Chemical Fabrics & Film Association Inc., EPDM Roofing Association, International Institute of Building Enclosure Consultants, Metal Construction Association, Metal Roofing Alliance, National Roofing Contractors Association, National Women in Roofing, Polyisocyanurate Insulation Manufacturers Association, Roof Coatings Manufacturers Association and Single Ply Roofing Industry.

The Quarterly Market Index Survey for Reroofing is available at bit.ly/RoofingSurvey. Survey responses may be submitted through April 20.

About National Roofing Contractors Association (NRCA)

Since 1886, the National Roofing Contractors Association has been the home for generations of entrepreneurial craftsmen and enterprises who shelter and protect America’s families and businesses and each other. Our vision is the recognition of our members as professionals and to unite the industry to that purpose. NRCA is one of the construction industry’s most respected trade associations and the voice of roofing professionals and leading authority in the roofing industry for information, education, technology and advocacy. It represents all segments of the roofing industry, including contractors; manufacturers; distributors; architects; consultants; engineers; building owners; and city, state and government agencies. For information about NRCA and its services and offerings, visit www.nrca.net.

By Emma Peterson. 

What the 2025 Q4 Market Index Survey can tell us about uncertainty and opportunity in the roofing industry.  

Hindsight is 20/20, so now that we're three months into the new year, we wanted to take a moment to look back at 2025. To do this, Heidi J. Ellsworth sat down with McKay Daniels, CEO at the National Roofing Contractors Association (NRCA), and Brian Pallasch, executive vice president and CEO of the International Institute of Building Enclosure Consultants (IIBEC), for a Roofing Road Trips® all about the 2025 Q4 Market Index Survey for Reroofing.  

Hosted by a coalition of industry trade associations and companies, including RoofersCoffeeShop® and the Polyisocyanurate Insulation Manufacturers Association (PIMA), this survey offers a quarterly look at the roofing industry’s business conditions. In the last survey of 2025, about 75% of respondents were roofing contractors and the remaining 25% were building enclosure consultants. Overall, their responses showed some hesitation and uncertainty that, for some, became a defining characteristic of 2025. Brian explained, “I don't want to put too much on it. But it appeared that there was a little bit of a slowdown in customer inquiries...Additionally, they reported that project backlog had fallen a little bit over the course of the last year. All of this indicates that the market was uncertain.” 

It is important to note that this uncertainty does not mean there weren’t areas of the industry that experienced a positive end to 2025. McKay explained, “You have to remember that roofing is not monolithic. For example, public work has slowed down, but data centers or very technical manufacturing facilities are in huge demand. And the folks working in that lane are as busy as they've ever been.”  

With all this in mind, the 2025 Q4 Market Index Survey for Reroofing tells a specific story about uncertainty, hesitancy and endurance. McKay explained, “We’ve been dealing with uncertain economies and world events for six years or more. And I think some of the slowdown we saw in the survey comes from contractors taking a pause to evaluate where they’re and look at reinvesting in training that allows them to get into some of those busy lanes and build a sustainable cadence that can survive that uncertainty.” 

Listen to the episode or Watch the recording to hear more of Daniel and McKay’s insights on the 2025 Q4 Market Index Survey for Reroofing. Do you want to help build a better understanding of the state of the industry? Make sure to participate in the first survey of 2026, which will open in April!

Coalition unites to protect roofing diversity and to defend sound building science.

A broad coalition of roofing industry organizations has successfully defeated Mississippi House Bill 1730, legislation that would have imposed a mandatory minimum 3:12 roof slope on all new public buildings constructed in the state.  

The measure, which passed the Mississippi House of Representatives before stalling in the state Senate, would have effectively prohibited low-slope roofing systems on public construction projects and eliminated proven, cost-effective roofing solutions used on schools, hospitals, government buildings and other public facilities nationwide. 

"This outcome proves the power of a united industry speaking with one voice," said Ellen Thorp, CAE, president and managing director of Coalition for Sustainable Roofing (COSUR). "Low-slope roofing systems have a decades-long track record of performance on public buildings. This legislation was well-intentioned but based on a fundamental misunderstanding of building science, and we're grateful the Mississippi Senate recognized that." 

"Low-slope roofing systems are a staple of commercial and public construction in Mississippi," said Christee Roberson, owner and president of Graham Roofing, Inc. in West Point, Mississippi. "This bill would have tied the hands of architects, building owners and contractors, and driven up costs for taxpayers in the process. We're glad the industry mobilized quickly and effectively to make sure that didn't happen." 

The Coalition for Sustainable Roofing (COSUR) led the advocacy effort, working in close coordination with the EPDM Roofing Association (ERA), the National Roofing Contractors Association (NRCA), the International Institute of Building Enclosure Consultants (IIBEC), the Asphalt Roofing Manufacturers Association (ARMA), the Polyisocyanurate Insulation Manufacturers Association (PIMA), the Single Ply Roofing Industry (SPRI), the Mississippi Roofing Contractors Association and approximately a dozen additional roofing-related organizations and industry partners. 

About Coalition for Sustainable Roofing

COSUR (Coalition for Sustainable Roofing) is an advocacy coalition representing leading U.S. roofing manufacturers committed to holistic roof system design and sustainable roofing assemblies. The coalition advocates for informed, system-level decisions and opposes overly restrictive policies not supported by local, real-world performance and field-verified outcomes. 

By Emma Peterson. 

PIMA president Justin Koscher breaks down what the Q4 Market Index Survey for Reroofing reveals.  

From 2025 policies related to immigration and tariffs to rising housing costs, there are a lot of different factors that are affecting the reroofing market this year. To track the actual effects of these factors, a group of national roofing industry trade associations sends out a survey called Market Index Survey for Reroofing.  

The goal of this survey is to track annual and quarterly changes in the roofing industry so that we all gain better insight into the successes and gaps of the reroofing market. And here at The Coffee Shops™, we are lucky to have Justin Koscher, president of the Polyisocyanurate Insulation Manufacturers Association (PIMA), giving us quarterly updates on what the survey is finding. Here’s an overview of what was reported in Q4 of 2025.  

Survey demographics 

• 75% roofing contractors 
• 25% roofing consultants 
• 90% working primarily in low slope or a blend of low and steep slope 
• 10% operating only in steep-slope roofing 

Material usage 

• 23% of roofing contractors who participated reported that the volume of materials installed increased in Q4 2025 compared to Q4 2024 
• 34% reported no change 
• 43% reported a decrease in materials installed

Customer inquiries 

• 24% of all respondents reported that customer inquiries increased for Q4 2025 compared to Q4 2024 
• 31% reported no change 
• 45% reported a decrease 
• The Customer Inquiries Index for the total industry dipped into negative territory for Q4 2025, dropping to 39.0 from 47.5 for Q3 2025.  

Please note: The Customer Inquiries Index is based on a 0 to 100 scale. A score of 50 or higher suggests expansion or optimism, while a value below 50 indicates contraction or pessimism.  

Project contracts 

• 28% of all respondents reported that project contracts increased for Q4 2025 as compared to the same quarter previous year 
• 34% reported no change 
• 38% reported a decrease 
• The Project Contracts Index for the total industry fell into negative territory declining to 45.2 for Q4 2025, down from 50.5 for Q3 2025.

Please note: The Project Contracts Index operates on the same scale as the Customer Inquiries Index. 

Project backlog (as of January 2026) 

• 28% of respondents reported a project backlog of three months or longer 
• 26% of respondents reported no project backlog  
• 45% of respondents reported a backlog of one to two months 

The takeaways 

According to the results, all business segments experienced a negative customer inquiry sentiment for Q4 of 2025. As for project contract questions, only businesses engaged primarily in low-slope roofing reported a positive outlook (rising to 52.0 for Q4 2025 from 48.9 for Q3 2025).  

The slowness of the market indicated by these two numbers is further supported when looking at the project backlog, which saw a nine-point decrease compared to the percentage of respondents that reported a backlog of three months or longer in October 2025.  

Want to help collect more powerful data like this? Look out for the Q1 2026 survey coming in April!

By Heidi J. Ellsworth.

The Annual Conference reinforced a clear message: regulatory momentum is not slowing down. 

Known for its excellent technical support and industry standards, the Single Ply Roofing Industry (SPRI) brought together leading single-ply roofing experts at the 2026 SPRI Annual Conference in Tucson, Arizona. The meeting served as a powerful reminder that technical leadership and regulatory awareness go together in driving high-level roofing systems and installation performance. With rapid shifts occurring at the federal level, discussions centered on how state regulations have become increasingly active and are now playing a leading role in shaping building codes and standards. A key highlight of the meeting was the technical report delivered by Chadwick Collins, SPRI technical director. Chadwick provided a comprehensive update on regulatory developments across the country, noting that state-level activity has surpassed that of past years. "Among the most notable updates is the potential legislation prohibiting low slopes on buildings using public funds in Mississippi, underscoring the growing emphasis on how legislation and regulation circumventing the common code acceptance process can lead to policies that are uniformed by the professionals in the industry." 

The discussion reflected a broader trend. As federal regulatory frameworks evolve, states are stepping forward with their own initiatives related to energy performance, material requirements and installation standards. This increased activity means contractors, manufacturers and consultants must remain vigilant in tracking changes that could directly affect design practices and jobsite compliance. 

Collaboration remains central to addressing these challenges. Leading organizations including the National Roofing Contractors Association (NRCA), the Polyisocyanurate Insulation Manufacturers Association (PIMA), the Asphalt Roofing Manufacturers Association (ARMA), International Institute of Building Enclosure Consultants (IIBEC) and the EPDM Roofing Association (ERA) are actively working with SPRI to monitor policy developments and advocate for balanced regulations that protect performance, innovation and safety. 

At the heart of SPRI’s impact is its commitment to industry standard development and maintenance. The association continues to be highly active in creating and updating technical standards that guide product performance, installation quality and alignment with building codes. These standards not only support manufacturers and contractors but also provide clarity for regulators and code officials seeking proven, effective solutions. Roofing professionals can explore SPRI’s standards work and regulatory engagement at SPRI.org to better understand how the association’s technical leadership supports the industry. 

The Annual Conference reinforced a clear message: regulatory momentum is not slowing down. With states taking a more prominent role and performance expectations continuing to rise, staying informed is essential. Through collaboration, standards development and proactive engagement, SPRI and its partners are helping ensure the roofing industry remains prepared, resilient and positioned for long-term success. 

By PIMA.  

HD polyiso cover boards help maintain roof durability by resisting impact, improving rigidity and supporting systemwide performance in severe weather. 

One critical piece of the roofing system that protects the roof assembly is the roof cover board. Roof cover boards endure hail, winds, rooftop traffic and the weight of rooftop equipment, all of which can put stress on the roof structure and even disrupt the overall roof assembly. To counter these pressures, most modern roof designs incorporate a protective layer that helps preserve long-term performance.  

Our team at Polyisocyanurate Insulation Manufacturers Association (PIMA) created this technical bulletin so you can learn the basics and the importance of polyiso insulation and roof cover boards.  

How do cover boards protect roof systems and enhance durability?  

Products like high-density (HD) polyiso cover boards are installed below the roof membrane and above the insulation layers. Cover boards are manufactured with higher compressive strengths as compared to other roof assembly layers. This hard surface dissipates energy from impact forces generated by hail, dropped tools and even foot traffic from roof and equipment maintenance personnel. In high wind scenarios, the rigidity of cover board materials reduces the risk of deflection uplift forces. 

How are roof cover board materials evaluated? 

While the performance attributes of roof cover board materials include R-value and water absorption, it is compressive strength that defines the role of cover boards as a protection layer. The compressive properties of HD polyiso cover boards are evaluated using ASTM D1621, "Standard Test Method for Compressive Properties of Rigid Cellular Plastics." Under this laboratory test method, loads are applied until deformation of ten percent (10%) of thickness or yield, whichever occurs first, is observed. 

Roof cover board materials are available in a range of compressive strengths. While gypsum roof cover board products are manufactured with higher compressive strength values, HD polyiso cover boards deliver fir-for-purpose protection for most roofing scenarios. Table 1 includes the minimum compressive strengths for HD polyiso cover boards as required under the applicable product standards in the United States and Canada. 

Table 1. Minimum requirements for compressive strength of HD polyiso roof cover boards by product standard. 

How do HD polyiso and gypsum roof cover boards compare? 

Is more always better when it comes to compressive strength? No. While gypsum roof cover boards are manufactured in higher compressive strengths, the products can provide over engineered solutions for most roofing scenarios. 

Like other factors for roof system performance, products should be selected with the entire assembly in mind. For certain hazards such as wind and hail, the entire roof assembly is evaluated and classified based on its level of performance. For example, roof assemblies evaluated for puncture resistance when exposed to hail are classified for "Severe Hail" or "Very Severe Hail." Roof assemblies that include HD polyiso cover boards can meet the "Severe Hail" performance requirements, which cover a significant portion of the U.S. regions that face severe hail threats. 

Roof cover boards should deliver fit-for-purpose performance when it comes to protecting roof assemblies against anticipated hazards. Table 2 compares how HD polyiso cover boards can deliver equivalent performance to gypsum products when the performance of the full roof assembly is considered. 

Table 2. Comparison of HD polyiso and gypsum roof cover boards by rooftop threat. 

Summary: Cover boards and compressive strength 

• Assembly performance: For weather threats like hail and high winds, roofs are evaluated as a complete assembly. In most cases, HD polyiso coverboards can be used to meet the applicable assembly performance criteria.   
• Fit-for-purpose: The available compressive strengths for HD polyiso cover boards provide suitable protection for most roofing scenarios versus the over engineered solutions found in gypsum options. 
• Additional protection: Where excessive or regular foot traffic is expected, roof system designers can implement the use of foot traffic pads as a best practice for directing and limiting the impacts of foot traffic on roof systems. 

Additional benefits 

HD polyiso cover boards deliver enhanced roof protection, but the advantages go beyond durability: 

• Widely available from more than 40 manufacturing sites in the U.S. and Canada. 
• Reduced freight and fewer trucks with single source shipping of both insulation and cover board products. 
• Provides a high R-value of R-2.5 when compared to alternative cover board options. 
• Lightweight boards for ease of installation (roughly 1/5 the weight of 1/2 inch gypsum boards). 
• Easy to cut without the need for special tools and virtually dust free. 

Before installing HD polyiso cover boards, project teams should always consult manufacturer data sheets for information on product performance and installation instructions. 

Original article and photo source: PIMA

By Polyisocyanurate Insulation Manufacturers Association (PIMA). 

Advances in HD polyiso materials are reshaping how professionals approach durability and energy efficiency. 

Roof system performance increasingly depends on smart material selection, particularly as energy codes tighten and weather-related risks intensify. Here at the Polyisocyanurate Insulation Manufacturers Association (PIMA), we know that today’s roofing professionals are placing greater emphasis on how insulation and cover board materials function within the overall roof system in order to deliver roofs that perform reliably in the long term. 

One material gaining attention is the high-density polyiso roof cover board. Traditionally specified as a protective layer beneath the membrane, HD polyiso cover boards now serve a broader role in modern roof design. These boards help improve overall roof resilience while supporting energy efficiency goals without increasing assembly thickness or complexity. 

What is an HD polyiso cover board and why it matters 

A cover board is a higher-density, protective component of a low-slope roof system that provides a stable substrate for roofing membranes and suitable protection for underlying insulation. HD polyiso cover boards take this protection to the next level by combining compressive strength and thermal efficiency in a single, versatile product. 

HD polyiso cover boards’ compressive strength protects roofs from hail, wind and loads 

Roof cover boards are often specified for applications where durability is key. This includes roofs that are subjected to extreme weather events (such as hail or high winds), consistent service traffic or those with renewable energy systems such as rooftop solar systems. For these scenarios, compressive strength is essential. 

HD polyiso cover boards are manufactured in three compressive strength ratings: 80 psi (ASTM C1289 Type II, Class 4, Grade 1), 110 psi (Grade 2) and 140 psi (Grade 3). These options allow professionals to select cover boards appropriate to the anticipated load and environmental conditions, thereby optimizing the roof system without unnecessary over-engineered solutions. Additionally, HD polyiso cover boards come as individual panels or composite products (with the cover board adhered to polyiso roof insulation boards) to enhance roof resilience in a wide range of applications. 

Evaluating HD polyiso versus gypsum roof cover board performance 

With high compressive strengths, roof assemblies that include HD polyiso cover boards can meet the "severe hail" performance requirements, which cover a significant portion of the U.S. regions that face extreme weather threats. While some professionals may still favor gypsum for its nominally higher compressive strength, it is critical to recognize that higher compressive strength does not automatically equate to better overall roof system performance. 

Over-engineering a roof can increase cost, weight and installation complexity without delivering meaningful improvements in durability or resilience under the conditions the roof is likely to encounter. Instead, roof cover boards should be specified based on fit-for-purpose performance, considering the overall assembly and potential hazards. 

Improving thermal efficiency with HD polyiso cover boards 

HD polyiso cover boards not only protect the roofing system but also enhance its overall energy efficiency. In fact, the boards outperform gypsum alternatives when it comes to thermal performance. A 0.5-inch HD polyiso panel provides an R-value of R-2.5, compared to R-0.5 for a gypsum cover board of equivalent thickness. 

In assemblies designed to meet prescriptive energy code requirements, such as an R-30 roof, the inclusion of HD polyiso cover boards reduces the additional insulation required. This additional R-value can be particularly advantageous in roof replacement scenarios where existing rooftop conditions may present height limitations for increasing insulation levels. 

By maximizing the thermal performance of each layer, including cover board, the roof system can achieve code compliance and energy efficiency without compromising assembly thickness or structural considerations. 

Additionally, the closed-cell foam core of HD polyiso roof cover boards is inherently water-resistant. When combined with facers like inorganic coated glass facers (CGF) and glass reinforced organic facers (GRF), HD polyiso roof cover boards offer additional moisture protection and resistance to mold or mildew growth. 

Designing roof systems for long-term performance and efficiency 

By focusing on the roof system as a whole rather than individual material metrics, professionals can optimize protection, efficiency and long-term value. HD polyiso cover boards demonstrate how modern roofing materials can simultaneously meet loading and thermal demands without compromise. When incorporated thoughtfully, these high-performance cover boards enable the design of roof systems that are not only durable and energy-efficient but also precisely engineered to the challenges of today’s built environment. 

For professionals seeking to make informed decisions, PIMA’s new Technical Bulletins, #502 The R-value Advantage of HD Polyiso Cover Boards, #503 Understanding Compressive Strength of Roof Cover Board Materials and #504 Evaluating the Moisture Resistance of Roof Cover Board Materials provide in-depth guidance on maximizing the value of HD polyiso cover boards. 

Original article and photo source: PIMA

By Hunter Panels. 

The choice of insulation impacts performance, safety, and cost for years to come. 

When it comes to commercial roofing, insulation plays a critical role in controlling energy costs, enhancing fire safety, speed of installation, and maximizing long-term ROI. However, not all insulation options are the same. Expanded Polystyrene (EPS) is a lightweight, rigid, thermoplastic insulation made from closed-cell foam. Polyisocyanurate (Polyiso) is also a closed-cell foam board, but it’s a thermoset material with a high-performance foam core sandwiched between two facers. Here at Hunter Panels, we want to help drive this convTersation forward with high-efficiency solutions built for today’s demands. Keep reading to understand the advantages and limitations of these two options and which option professionals focused on performance and value are choosing. 

Advantages of polyisocyanurate over expanded polystyrene: 

Long-term thermal resistance (LTTR) 
Long-Term Thermal Resistance (LTTR) is a scientifically supported method to calculate the 15-year, time-weighted average R-value of closed-cell insulation products. Polyiso insulation has a high R-value per inch (5.7) compared to other insulation products on the market. EPS insulation’s R-value varies depending on the density of the foam and can range from 4 to 5. This performance characteristic allows polyiso insulation to deliver greater energy savings potential in thinner product thicknesses, which can be advantageous in height-restricted areas. 

Flexibility in roofing assemblies 
Polyiso insulation is compatible with most types of cladding and roofing materials, such as metal, brick, stone, wood, vinyl, asphalt shingles, etc. It can be attached with adhesives, mechanical fasteners or hot mopping. Polyiso is also lightweight and easy to cut and install. In comparison, EPS is not compatible with some types of cladding and roofing materials, such as adhesives, hot mopping or torch-down roofing, without the use of slip sheets or additional cover boards. It can be damaged by high temperatures or solvents and requires a protective layer or coating to prevent UV degradation. EPS can also be molded into different shapes and sizes to fit various design needs. 

Fire resistance 
Polyiso insulation is a thermoset material that does not melt or drip when exposed to flame (ASTM E84). In comparison, EPS is less fire-resistant; it melts and drips when exposed to high heat, which can spread the fire and create toxic fumes. Polyiso also offers a direct-to-deck attachment option for steel deck roofs (FM 4450/UL 1256). 

Environmental and other attributes 
Polyiso insulation contains blowing agents with zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP), reducing buildings’ energy use and associated greenhouse gas emissions. It is also recyclable through reuse where permitted and contains recycled content, which varies by product. While EPS can also contain recycled content, polyiso insulation’s high thermal efficiency results in energy savings potential equal to 47 times the product’s embodied energy. 

In conclusion, the choice of insulation material for a commercial roof system is a critical decision that directly impacts the building’s performance, energy efficiency and overall value. Polyiso insulation is the superior choice due to its exceptional thermal efficiency, fire resistance, ease of installation, environmental sustainability and long-term cost savings. Please see the links below from the Polyisocyanurate Insulation Manufacturers Association (PIMA) for unbiased manufacturer resources.[i] 

[i]  https://www.polyiso.org/

Original article and photo source: Hunter Panels

By Polyisocyanurate Insulation Manufacturers Association (PIMA). 

Using HD polyiso cover boards can reduce installation time, improve energy performance and strengthen the long-term reliability of roof systems. 

High-density polyiso cover boards are becoming a preferred choice for modern roof assemblies, offering durability and thermal performance in a single solution. The Polyisocyanurate Insulation Manufacturers Association (PIMA) highlights that these boards provide meaningful insulating value, delivering approximately R-2.5 at a standard 0.5-inch thickness, which can help roof systems meet or exceed prescriptive energy code requirements for insulation installed entirely above the deck. When paired with polyiso insulation, these cover boards strengthen the thermal layer of the assembly and support compliance with the International Energy Conservation Code and ASHRAE Standard 90.1. 

For reroofing projects where deck height limitations restrict how much insulation can be added, maximizing R-value per inch becomes essential. Using high-density polyiso cover boards allows project teams to increase total thermal resistance without significantly increasing roof thickness. PIMA notes that some manufacturers also offer composite boards that combine a high-density cover board with polyiso insulation in one product, streamlining installation and reducing labor time while maintaining the performance needed for energy-efficient roof systems. 

Energy code compliance with HD polyiso cover boards 

Under current versions of the International Energy Conservation Code and ASHRAE Standard 90.1, roof assemblies with insulation installed entirely above deck (IEAD) are required to meet minimum continuous insulation requirements. The minimum insulation requirements apply to both new construction and roof replacement projects on existing buildings. For roof replacement projects, maximizing the R-value per inch can be critical when existing rooftop conditions present thickness limitations. 

Minimum R-value requirements for roof assemblies typically range from R-25 to R-35 depending on the climate zone. The assembly configurations below demonstrate how HD polyiso cover boards can be combined with polyiso roof insulation to meet these minimum energy code requirements. Figures 2a-2c also include the thickness savings when HD polyiso cover boards are installed compared to assemblies that use insulation with a traditional gypsum cover board to meet the applicable energy code requirements. 

Why R-value matters in cover boards 

• Optimized design: Cover boards that are rated as an insulating material can reduce the thickness of insulation required to meet minimum energy code requirements. 
• Thickness limitation: Roof replacement projects can present unique challenges when energy codes require the installation of increased insulation levels on existing buildings. Installing HD polyiso cover boards with an R-value of 2.5 maximizes energy efficiency on a per inch basis when compared to traditional cover board products. 
• Energy loss: Mechanically attached roof systems installed with conductive fasteners create thermal bridges and reduce the overall energy efficiency performance of the roof system. HD polyiso cover boards can be installed with adhesives on top of mechanically attached polyiso insulation base layers effectively burying the fasteners below a thermal layer. This can reduce the impact of thermal bridges and increase the performance of the roof system. 

Additional benefits 

HD polyiso cover boards deliver enhanced roof protection and energy savings all in one product, but the advantages go beyond energy efficiency: 

• Widely available from more than 40 manufacturing sites in the U.S. and Canada. 
• Reduced freight with single source shipping of both insulation and cover board products. 
• Available in various compressive strengths, facers and board sizes to meet your project specific needs. 
• Lightweight boards for ease of installation. 
• Easy to cut without the need for special tools and virtually dust free. 

Before installing HD polyiso cover boards, project teams should always consult manufacturer data sheets for information on product performance and installation instructions. 

Original article and photos source: PIMA