Selection Criteria for Plaza Deck Waterproofing Systems

Plaza decks can do more than extend a building’s function, they can provide park-like respites, private meeting spaces, sustainable features, and parking. Built on occupied spaces, like rooftops, they also introduce substantial risk. After the plaza deck is finished, locating the source of moisture intrusion and repairing the waterproofing system is challenging, with multiple factors complicating success. Moisture enters through tiny gaps, often in transition points, interfaces, and penetrations and migrates laterally into the building.

Project teams must take additional care designing, specifying, and constructing the plaza or podium. Waterproofing membranes alone do not adequately protect a roof but can thrive when part of an integrated system that includes field quality assurance. Not all systems work in all conditions or applications. One waterproofing system may provide robust protection for some decks and expose others to significant risk during and after construction.

Substrates and Interfaces

The goal is to design the complete plaza deck assembly with each component working together to manage water, movement, and other project-specific risks. Long-term performance hinges on how the membrane interacts with the substrate and adjacent components and whether it creates a continuous watertight seal or allows gaps at penetrations, tie ins, and transitions.

Not all waterproofing membranes are installed the same or deliver the same results. Different methods not only impact the installation timeframe but can also perform differently at penetrations and joints. Some systems work better with certain substrates while others are better at creating continuous protection.

Before choosing a waterproofing system, evaluate potential interactions between product materials as well as the substrate, roofing, waterproofing, and drainage systems. For example, chemical compatibility between the plaza deck waterproofing and air barrier or below grade waterproofing system is essential to deliver optimal performance.

Application and Project Demands

Consider the plaza deck’s application before selecting a waterproofing system and identify:

• How the installation process could impact operations and occupants. Will the corresponding noise, odors, or work disrupt operations or potentially harm occupants?
• The time needed to perform each step and how it affects construction timelines.
• The risk the construction process poses to the waterproofing membrane. Will heavy equipment be placed on the membrane and potentially damage or puncture it?
• The membrane’s ability to resist puncture from environmental and applications factors, such UV rays, roots from vegetation, and precipitation.
• Curing requirements as well as type and intensity of traffic on the new membrane.
• Project scheduling needs and the impact the concrete cure or substrate repair time could have.

Project Considerations

• Substrate: Condition, moisture level, compatibility
• Movement: Crack bridging, flexibility, thermal cycling
• Detailing: Penetrations, transitions, changes in plane
• Traffic: Construction, pedestrian and vehicular exposure
• UV Exposure: Exposure during and after construction
• Water Exposure: Drainage, immersion and water containment
• Overburden: Pavers, landscaping, concrete toppings, green roofs
• Installation: Cure time, temperature, equipment and labor
• Schedule: Time to subsequent trades and traffic readiness
• Lifecycle: Accessibility, durability and maintenance
• Application: Plaza deck usage and related vulnerabilities

Waterproofing System Options

Henry's waterproofing portfolio features multiple proven technologies, including self-adhered sheet waterproofing, cold-applied liquid waterproofing, hot-applied rubberized asphalt, advanced resin systems, polyurea, and PUMA systems.

Connect With Us On Your Next Plaza Deck Project

Choosing Henry's integrated solutions ensures peace of mind through continuous, compatible systems that are well-designed, thoroughly tested, and backed by comprehensive support. Our approach guarantees a high-performing, durable, and efficient building envelope. Contact us today to discuss how we can help with the design of your next project.