The Secrets to Specifying PVC, PVC KEE and KEE
Understanding Test Methods, Plasticizers and Membrane Properties for the PVC Specification You Want
Sponsored by GAF | Siplast | Presented by Andrea Wagner Watts and Tim Clepper, RRC, RRO
Live Webinar Airing on February 24, 2026 at 02:00 PM ET
Navigating the world of PVC roof membranes can be complex due to two different ASTM specifications (ASTM D 4434 and ASTM D 6754) and variations in membrane composition, particularly those including the KEE plasticizer. When you factor in differences in chemical resistance performance, accelerated aging testing, and overall durability expectations, choosing the right membrane can feel like a real challenge. This presentation is designed to cut through the confusion. It will provide clear definitions and performance insights for PVC, PVC KEE, and KEE membranes. Attendees will leave with precise, actionable specification language to ensure the roofing membrane installed on their project delivers the intended, long-term performance.
Photo courtesy of GAF
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Andrea Wagner Watts is the Building Science Education Manager for GAF | Siplast Building & Roofing Science, engaging with industry professionals to provide guidance, technical support and education for roof and wall assemblies. With more than 15 years of experience in the industry, Andrea strives to improve the overall performance of the building enclosures through application innovation, product development and building science research. Andrea has published on building science, assembly interfaces, durability and resilience and holds multiple patents. She is the chair of the Air Barrier Association of America and chairs the ASTM E06 and D08 Task Groups on air barriers assemblies. |
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Tim Clepper, RRC, RRO, is a Building Design Manager for GAF|Siplast in the Southwest Region of the US. Tim is a Registered Architect (RA) in Texas and Louisiana as well as a Registered Roof Consultant (RRC) and Registered Roof Observer (RRO) as certified by the International Institute of Building Enclosure Consultants (IIBEC). He has over 15 years of architectural, roofing and building enclosure design, product specification and consulting experience on various types of building projects, including commercial, K-12, federal, state and local universities/colleges, athletic facilities, healthcare, historic preservation/rehabilitation, industrial, multifamily and single-family residential. Tim is also a board member of the Gulf Coast Chapter of IIBEC and is a member of the American Institute of Architects (AIA). |
The Building and Roofing Science team offers regional expert building enclosure collaboration through design, specification, and educational support for customers of GAF and Siplast, both Standard Industries companies. GAF is North America’s largest roofing manufacturer with more homes and businesses in the U.S. protected by a GAF roof than any other product. Siplast, a leader in building enclosure systems, offers a portfolio of advanced, high-performance SBS-modified bitumen, PMMA liquid-applied, PVC KEE, lightweight insulating concrete, wall air & water barrier systems, and amenity/vegetated systems.
Originally published in Building Enclosure
Originally published in January 2026
LEARNING OBJECTIVES
- Differentiate between PVC, PVC KEE and KEE membrane types (ASTM D 4434 Type II, III, and IV) and ASTM D 6754) based on composition and properties.
- Explain the critical role of plasticizer in PVC membrane performance, including its effect on long-term performance and chemical resistance.
- Compare accelerated aging, chemical resistance and impact resistance results from various membranes to understand the differences.
- Identify performance specification language for use in specifying the best PVC or PVC KEE membrane for a given project.
