NSF/ANSI 347 certified products can help projects earn points toward LEED certification.

Gaskets must meet ANSI/ASME B16.21 or ISO 7483 dimensions, with a new allowance for thermal expansion in PTFE-based materials. The 2021 edition adds a maximum warpage of 0.5 mm per 100 mm of gasket length.

The standard rewards manufacturers who go beyond the minimum requirements, acknowledging unique advancements in sustainability, such as new recycling technologies or innovative, low-impact raw materials. Conformance Levels: Understanding the Certification

Rewards manufacturers for implementing new technologies or reclamation processes that exceed current standard requirements. Certification Levels

This paper outlines the significance, structure, and impact of , the leading national standard for evaluating the sustainability of single-ply roofing membranes.

Assesses the long-term performance and repairability of the membrane in various climate zones to ensure longevity. Corporate Governance:

By setting these tiers, the standard allows architects and building owners to specify roofing materials that meet their specific project goals, whether that's achieving a base level of compliance or pursuing the highest Platinum certification.

Developed through NSF International , in collaboration with industry stakeholders, the NSF/ANSI 347 standard is designed to assess the sustainability profile of single-ply membranes. These include (Ethylene Propylene Diene Terpolymer), PVC (Polyvinyl Chloride), TPO (Thermoplastic Polyolefin), KEE (Ketone Ethylene Ester), and PIB (Polyisobutylene).

Understanding NSF/ANSI 347-2021: The Gold Standard for Sustainable Roofing Membranes

Rather than offering a simple pass/fail grade, products reviewed under NSF/ANSI 347 receive one of four distinct, verified certification levels based on their point totals:

To earn NSF certification under the 2021 edition, a gasket must pass four battery tests:

, a standard originally published in 2012 and regularly updated (with a version relevant to current industry benchmarks in 2021). It is the first American National Standard to evaluate and certify the life-cycle sustainability of single-ply roofing membranes used on commercial buildings. BuildingGreen Overview of NSF/ANSI 347