Regulations and roofs: Next generation insulation and sustainable VRA design

Blog in Brief

Regulatory changes across Canada and parts of the U.S. have lowered the amount of hydrofluorocarbons (HFCs) that can be used in the production of extruded polystyrene insulation (XPS), prompting the launch of Owens Corning FOAMULAR® NGX™ (Next Generation Extruded) insulation. The redesigned material maintains the same qualities as earlier versions of the insulation, including water resistance, R-value and compressive strength, while completely eliminating the use of HFC 134a. This innovation makes the new material ready for inclusion in vegetative roof assemblies because, in addition to reduced Global Warming Potential (GWP), it provides a high compressive strength, has a closed-cell structure and is hydrophobic, which helps it shed moisture and maintain thermal performance when water is present in low-slope roof applications.

Regulations and Roofs: Next Generation Insulation and Sustainable VRA Design

Regulatory changes across Canada and parts of the U.S. have been put into place to address concerns about high global warming potential (GWP) materials used in multiple industries. For the insulation and building sector, the main change in the new regulations is the need to alter the blowing agent used in extruded polystyrene insulation (XPS). However, swapping HFC 134a – which had been a common ingredient used by multiple companies – for a low-GWP blowing agent was not a simple process.

Regulation change

First introduced during the Kigali Amendment to the Montreal Protocol, the new regulations took effect in every Canadian province at the start of 2021.¹ At the same time, the required use of low-GWP XPS also started in several U.S. states; however, rollout of the new legislation has been patchwork. States that have already changed regulations include California, Colorado, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Rhode Island, Vermont, Virginia and Washington. Several additional states have proposed similar legislation to take effect in 2022. 

An updated map showing locations in North America where the regulations have changed is available here.

Introducing NGX

To address the new regulations, the Owens Corning material science team spent more than six years creating and testing new blowing agent formulations. The blowing agent is what provides XPS insulation its specific qualities. The goal was to completely eliminate the use of HFC 134a and maintain all the properties found in XPS, meaning that the redesign was a complicated process. However, the team developed a new, proprietary blowing agent that provided a 90% reduction in GWP and eliminated the use of HFC 134a.²

New Owens Corning FOAMULAR® NGX™ insulation has a high R-value that can be maintained even in the presence of water, and it is available in a wide range of comprehensive strengths – up to 100psi. The insulation also carries a lifetime guarantee that it will provide at least 90% of its initial R-value for the product’s lifetime. Additionally, the insulation was designed to have the same application process as FOAMULAR® XPS. It still uses the same fasteners and adhesives, and is cut and installed exactly the way the previous incarnation of the insulation was.

Practical sustainability

In addition to reducing the GWP of the blowing agent, FOAMULAR® NGX™ sought to address its footprint in other ways. It is manufactured using wind energy and includes at least 20% recycled polystyrene – certified by Scientific Certification Systems. This product has GREENGUARD Gold certification. The reduction in GWP means use of the insulation counts as 1.5 products towards LEED 4.1 points for options 1 and 2.

For designers and architects working in states that changed their regulations and in locations that have yet to do so, the sustainability attributes mean FOAMULAR® NGX™ can be used to help builders achieve certifications like LEED, Energy Star® and Green Building Standard ICC 700-2008.

An area of interest for early adopters of the new FOAMULAR® NGX™ insulation or practical example of a use case where FOAMULAR® NGX™ would potentially help architects and designers’ further sustainability or certification goals would be in vegetative roof assemblies.

Vegetative roof assemblies can be used to help manage water and storm runoff and prevent the development of urban heat islands by supporting green spaces. However, they face a range of challenges, because the insulation used needs to be water resistant both during exposure to rain and also when storing water for plants, plus have enough compressive strength to manage static and live load from planted gardens and traffic.

Conclusion

The development of FOAMULAR® NGX™ cuts the use of a high-GWP blowing agent and provides an even more sustainable insulation option when designing protected membrane roof assemblies such as VRAs or plaza decks that can store stormwater and reduce the urban heat island. Elsewhere in the building envelope, it can also be a way to support sustainable designs in states where regulations regarding HFCs are in place. The insulation’s performance and characteristics allow it to be used in a range of situations, including when moisture is present or high levels of compressive strength are needed, such as in a vegetative roof assembly.

Listen to this recent podcast where Jose Mendez-Andino, VP of research and development, Owens Corning chats with Building Enclosure magazine about recent material innovations. Or, find more information on the new regulations and their rollout across the U.S.

References