A construction site with a person in a yellow shirt and white hard hat spraying EPRO Geo-Seal Bond on a vapor intrusion barrier system.


Vapor intrusion can be a significant safety issue on new builds or site renovations. Unlike many other health and safety hazards that can be observed on sites, vapor intrusion is typically invisible. Unfortunately, this means that it is frequently overlooked, and protections against it not implemented adequately (if at all!). Vapor intrusion can cause serious damage to the structure of buildings and the health and safety of their occupants.

A vapor intrusion mitigation system (VIMS) involves installing solutions that prevent vapor intrusion and its resulting problems. EPRO’s Geo-Seal line of products was designed specifically to provide reliable, long-lasting vapor intrusion mitigation for construction and renovation projects of all kinds.

What is Vapor Intrusion and What Are the Dangers?

Vapor intrusion occurs when chemical vapors migrate from outside a building into the structure. It is a serious concern for developers, as it can severely reduce the quality of the air breathed by a building’s occupants.

While not all vapors are harmful, many contain dangerous contaminants like volatile organic compounds (VOCs) methane, benzene and trichloroethylene. Contaminants are often present in the soil beneath building structures. While many construction sites are polluted with these contaminants, that doesn’t make vapor intrusion inevitable — in fact, it can be prevented with the right materials.

Failing to mitigate vapor intrusion can have severe consequences and cause many problems for human health and the structure of the building itself.

Developers and contractors can be morally, professionally and even legally liable for any of these serious consequences if they could have been prevented by sufficient VIMS. Legal requirements for VIMS vary from state to state, and organizations like the Interstate Technology Regulatory Council (ITRC) help local regulators develop these. ITRC vapor intrusion mitigation information, education and training can be found here.

How Can Vapor Intrusion be Prevented?

The typical VIMS methods and systems are separated into two main categories — passive VIMS and active Sub-slab vapor collection systems are installed underneath the building's structure.

A passive mitigation system may be comprised of vapor intrusion barriers, which are watertight membranes that vary in thickness and material, venting layers that force vapors to disperse outside building structures, concrete to seal gaps or cracks, or any combination of all three materials.

An active system can include sub-slab depressurization (SSD) systems with suction pits and electric fans, HVAC systems that control airflow - which help by typically directing air out of the building - or a combination of both.

Many VIMS include both passive and active elements.

How EPRO’s Geo-Seal Line Prevents Vapor Intrusion

While simple VIMS such as installing tape can offer limited protection against vapor intrusion, it is safer and more reliable to opt for professional, specially-designed solutions. Our Geo-Seal line consists of several such products that can be implemented to create a highly-effective VIMS that stands the test of time.

Geo-Seal products are superior to other VIMS products on the market due to their sheer performance, which has been tested extensively. Our experts have years of experience in the construction industry and with tackling vapor intrusion, which they have used to design highly effective solutions. Our products are based on a unique method called Redundant-Field Installed Composite Design that has proved extremely successful in a range of projects over many years.

The Geo-Seal range is also highly scalable and can be customized to meet a wide variety of different project sizes, features and conditions.

  • Geo-Seal 100: Geo-Seal 100 is one of our most popular products with over 50 million square feet installed over the last 20 years. What’s more, third-party tests have shown it to be the most chemically-resistant vapor intrusion barrier available on the market. It consists of three layers: Geo-Seal BASE, Geo-Seal CORE (60 mil) and Geo-Seal BOND. This product has been proven extremely effective against VOC vapors and is highly durable and puncture-resistant.

    A diagram of EPRO Geo-Seal 100 sub-slab vapor intrusion barrier system.
  • Geo-Seal EV-80: Geo-Seal EV80 is a composite barrier system that combines HDPE, EVOH and polymer-modified asphalt. At only 79 mil thick, it is still highly resistant to contaminants and includes an EV30 layer, a CORE layer and a BOND layer. Geo-Seal EV80 is highly versatile for many site conditions and boasts high chemical resistance at a relatively low thickness.

    A diagram of EPRO Geo-Seal EV-80 composite vapor intrusion barrier system.
  • Geo-Seal 60: Geo-Seal 60 is a composite VIMS barrier that includes a FILM 11 layer, a CORE layer and a BOND layer. It was designed as a cost-effective barrier that beats single-sheet membranes in durability, chemical resistance and the robustness of seals. Geo-Seal 60 is comparable in price to single-sheet membranes but offers extra layers of protection.

    A diagram of EPRO Geo-Seal 60 composite vapor intrusion barrier system.
  • Geo-Seal EV40s: Geo-Seal EV40s is a chemically-resistant single-sheet VIMS barrier consisting of an EVOH membrane and a geotextile later. It includes a CORE spray membrane that outperforms traditional tape sealing and creates a vapor-tight seal. Ideal for lower-risk sites and quick installations, Geo-Seal EV40s also works particularly well alongside active sub-slab ventilation systems.

    A diagram of EPRO Geo-Seal EV40s Single sheet EVOH geocomposite vapor intrusion barrier.

  • Geo-Seal EFC: Geo-Seal EFC is a complete VIM coating system consisting of 6 mil EFC PRIMER and 20 mil EFC coating. The formula provides significantly more effective chemical resistance than other epoxy resin-based coating products and can be applied to existing surfaces such as concrete floors. Geo-Seal EFC is recommended for projects such as those where active sub-slab vapor collection systems are to be retired but VIM is still required, and those where the removal of an existing concrete slab is to be avoided.

    A diagram of EPRO Geo-Seal EFC chemically-resistant coating.