Whether you're tackling preemptive mitigation or addressing higher-risk contamination, our Geo-Seal systems offer solutions for a wide range of site conditions. Geo-Seal systems feature composite and single-sheet membrane systems designed to seal off exposure pathways, which are essential for protecting indoor air quality by preventing the buildup of harmful vapors beneath buildings.
In this post, we’re putting the spotlight on two single-sheet options in the Geo-Seal range — EV40 and EV20—affectionately referred to as the "EV Twins." These robust vapor intrusion barriers come in different thicknesses but ultimately achieve the same goal: Safeguarding buildings from hazardous vapor infiltration.
What Are EV40 and EV20?
Geo-Seal EV40: A high-performance vapor barrier, featuring an EVOH membrane (Ethylene Vinyl Alcohol) reinforced with a durable geotextile layer. This combination creates a single-sheet barrier that is chemically resistant, easy to install, and offers additional built-in protection when placed over gravel substrates. The thicker 40 mil membrane makes EV40 an ideal solution for sites requiring extra defense against vapor intrusion.
Geo-Seal EV20: EV20 is also made with the same EVOH membrane, yet with a slightly thinner 20 mil barrier. While it is equally reliable in protecting against vapor intrusion, it is best suited for projects preemptively mitigating their risk or active subslab depressurization (SSD) systems. EV20 enhances the efficiency of these active systems, helping to optimize overall vapor mitigation.
Key Similarities Between the EV40 and EV20
While EV40 and EV20 differ in thickness, their core capabilities are very much aligned. Both systems:
Are Ideal for Low to Moderate Vapor Risks: Both EV40 and EV20 excel on sites where vapor concentrations don’t necessitate more robust composite VI mitigation barriers. They are also excellent choices for large, wide-open sites where fast installation is a priority.
Support Active SSD Systems: Both products integrate seamlessly with sub-slab depressurization (SSD) systems. Whether you're voluntarily mitigating Vapor Intrusion or addressing a higher risk, these barriers complement and enhance the efficiency of SSD installations.
Feature Robust Seam Sealing and Testing: Both systems utilize the Geo-Seal CORE spray membrane to seal seams, penetrations, and terminations, creating a continuous vapor barrier. Unlike basic tape sealing methods, Geo-Seal CORE ensures a high-quality, vapor-tight seal -- and rigorous smoke testing is performed on all EV40 and EV20 applications to confirm complete seal integrity.
Key Differences Between Each System
Thickness:
EV40: The thicker 40 mil membrane provides enhanced durability, meeting most state and federal minimum thickness requirements for passive vapor mitigation systems. It is well-suited for larger or more complex projects that demand stronger protection.
EV20: With a 20 mil membrane, EV20 is thinner, making it a great option for sites where minimal vapor risks exist or for voluntary mitigation efforts. Despite its thinner profile, it offers the same chemical diffusive properties as 60 mil or 80 mil HDPE liners, making it a cost-effective choice for specific applications. It is also well-suited to projects with fewer penetrations and is appropriate for large buildings or where mitigation is a proactive measure.
Regulatory Compliance:
EV40: Complies with most states and federal minimum thickness requirements of 30 mils for passive vapor mitigation barriers, making it a safe choice in a wide range of regulatory environments.
EV20: Its 20 mil EVOH membrane may not meet 30 mil minimum passive vapor mitigation requirements on its own, but it is still a Class A vapor barrier.
Real-World Applications of the EV Twins
Geo-Seal EV40 and EV20 have been successfully implemented in a variety of projects, both large and small, across different industries. Check out some of our featured case studies:
Alexan Bothell, Seattle area
Limelight Hotel, Denver area
Industrial Site, Newark, NJ
Selecting the Right Barrier for Your Site
At EPRO, we understand that every project is unique. Whether you’re dealing with a low- or higher-risk environment, our team can help you select the ideal vapor intrusion barrier to meet your needs. Our experts are here to evaluate your site conditions, recommend the most effective solution, and ensure your project is fully compliant with all regulations.
Ready to get started? Let's discuss your site’s specific requirements, and determine which Geo-Seal system is the best fit.