As below-grade construction grows more complex, long-term waterproofing performance depends on more than selecting a membrane. It requires coordination between design intent, product selection, site conditions, detailing, construction sequencing, installation quality, drainage, protection, and inspection. This webinar examines below-grade waterproofing as a system, with a practical focus on the details and interfaces that most often determine long-term performance.

Presenters will discuss common mechanisms of water intrusion and review critical conditions such as terminations, transitions, penetrations, laps, seams, drainage, protection layers, and tie-ins between pre-applied and post-applied assemblies. A short technical segment will also address lateral water migration and bond development in pre-applied waterproofing systems.

This discussion may include how different membrane technologies bond to concrete, the role of concrete placement and heat of hydration in bond formation, and how laboratory testing should be interpreted in relation to real construction conditions. The session will also note that the lateral water migration procedures currently debated in the industry are modified laboratory approaches rather than an official standardized ASTM test method, and that such testing typically evaluates bond in the field of a sheet membrane to a small concrete sample rather than complete system performance at laps, seams, penetrations, transitions, and terminations.

Through expert discussion and case-study analysis, attendees will gain practical insight into evaluating waterproofing performance claims, coordinating details and inspections, and specifying below-grade systems that support long-term building durability and occupant protection.

Learning Objectives:

1. Identify common mechanisms of water intrusion in below-grade construction and explain how waterproofing system selection, drainage, and project conditions influence long-term durability and occupant protection.
2. Evaluate critical detailing conditions, including terminations, transitions, penetrations, seams, laps, and tie-ins, to improve waterproofing continuity and reduce the risk of failure.
3. Describe how construction sequencing, substrate conditions, concrete placement, protection, inspection, and coordination across trades affect below-grade waterproofing performance.
4. Interpret technical data and testing related to pre-applied waterproofing, including bond development and lateral water migration considerations, while recognizing the limitations of modified laboratory tests compared with complete system performance in real-world field conditions.

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