Strategies for High-Performance Below-Grade Waterproofing  

Designing a high-performance building enclosure requires more than just surface-level protection; it demands a rigorous, performance-based mastery of below-grade water and gas mitigation. This discussion will provide an expert-level analysis of below-grade waterproofing within the comprehensive framework of the high-performance building enclosure.

Participants will examine the fundamental physical forces—hydrostatic pressure, capillary action, and water table dynamics—that jeopardize structural longevity. Participants will evaluate the two most common below-grade application methods: positive-side and blindside (pre-applied) systems, with a focus on selecting successful product and system solutions for complex urban project conditions. 

We will also explore the key technical performance attributes of different product technologies and types of waterproofing membranes, as well as address passive and active gas-resistant membrane systems for contaminated sites. We will cover how to eliminate scope gaps and foster essential coordination between designers, manufacturers, and contractors to ensure a seamless, high-performance building enclosure.

By the end of this session, attendees will be equipped to mitigate the risk of common enclosure failures through evidence-based design and coordinated technical documentation.

Photo courtesy of Siplast

Benjamin Meyer is the Building Enclosure Business Director with Siplast. Previous experience includes: enclosure consultant principal, technical management for enclosure products, architecture, real-estate development and construction management. He serves as a past Member of the LEED Technical Committee, Chair of the ASHRAE 90.1 Envelope Committee, and a Director of ABAA.

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 serves as an executive board member of ABAA, is the co-chair of their Technical Committee and chairs the ASTM E06 and D08 Task Groups on air barriers assemblies.