Blog

How the Diffusion of Chlorinated Solvents and VOCs Impact Your Building Design

Download Now: Your Guide to VOCs and Building Design

The Importance of a Properly Installed Vapor Intrusion Barrier 

VOCs-and-building-design

If you’re developing a project where there are chlorinated solvents and/or other volatile organic compounds (VOCs) in the ground, we hope it’s because you understand the complexities involved. This includes conducting environmental site assessments, any requisite groundwater, soil, and soil vapor testing, and all the due diligence that comes along with the careful work of brownfield redevelopment. 

In other words, we hope you didn’t arrive at this article because of some unwelcome surprise. VOCs beneath the foundation present health hazards to a building’s present or future occupants but can be mitigated in the design process of these sites with unique care and attention. 

The key to designing and building the optimal projects on these sites requires the selection of high-quality products and a proper installation process to create something safe for its inhabitants and profitable for its owners. 

How Volatile Organic Compounds Impact the Building Envelope 

Maybe you’re building where there once was a dry cleaner or a gas station, or you’re rehabilitating a large industrial site for a new use such as a multi-family development. In these cases, the presence of chlorinated solvents like trichloroethylene (TCE), tetrachloroethylene (PCE), or hydrocarbons like petroleum products are almost a given. Other soil gases, like methane, might be expected based on location. VOCs pose a design consideration for buildings by their introduction into the building envelope over time, finding preferential pathways to enter the concrete foundation. 

When it comes to soil vapors, both diffusion and advection can carry harmful chemicals right into your building envelope. Diffusion is the process where chemicals spread from areas of high concentration to low concentration, while advection involves the movement of chemicals through the soil driven by air or water flow. No matter the path these vapors take, experts agree on one thing: a vapor intrusion barrier is critical.  

how-diffusion-travels-via-building-envelope
The reason healthy building design has evolved to mitigate these conditions is because we know the future health impacts are severe: respiratory issues, cancer risks, neurological effects, cardiovascular issues, allergies and skin conditions, reproductive effects—the gamut of human health hazards. A high-performance vapor intrusion barrier is a critical component in helping to prevent the transmission of dangerous chemicals into your building, creating a safer, healthier environment for everyone inside. 

The Different Types of Design Considerations for Site Mitigation 

Brownfield redevelopers know the design of their building begins many feet below the foundation of their project. It can start with a remediation plan, where the site may be treated with in situ soil remediation, or existing earth is trucked out and replaced with uncontaminated dirt. Granular fills might come next. Ventilation systems below the slab, in the form of a sub-slab depressurization system (SSDS) or a sub-slab venting system (SSVS), can create a negative pressure differential or airflow that keeps the VOCs out of the building envelope. Sometimes the actual layout of the building may change—a parking garage might create a buffer between the ground and the indoor space.  

These tried-and-true methods are vital to healthy building design. But when we talk about adaptability, open-mindedness, and a desire for learning to design a healthy, effective building, we’re talking about the other facet of design considerations: product selection. 

To design a building that is both healthy and profitable, designers need to select product solutions that are responsive to their specific conditions, flexible to both their site and project timeline, and must always be cost-effective. 

Responsiveness: Does the Product Protect Against What’s on Your Site? 

 The brownfield redevelopment market has seen extraordinary progress in recent years in the efficacy of products designed to prevent vapor intrusion. The products have improved in both performance and versatility. In short, vapor intrusion products can do more things, and do them better. But which things can change every time you’re designing a new project. Matching a vapor intrusion product to your specific site conditions cannot simply be, “This is what I’ve always used.” You might be paying for something you don’t need, but you might also be selecting something that’s not engineered for the specific conditions on your site. 

Before the selection of the vapor intrusion barrier, VOC testing is a crucial step in brownfield redevelopment, aiding in the identification and management of volatile organic compounds in the soil, groundwater, and soil vapor. Advanced techniques like gas chromatography-mass spectrometry (GC-MS) are used to detect and quantify the presence of contaminants such as chlorinated solvents and hydrocarbons. 

The insights gained from VOC testing guide the selection of specific mitigation strategies and vapor intrusion barriers, helping tailor the strategy to the site's contamination profile. Ongoing testing throughout the redevelopment process is vital for the continued safety of the site and its future occupants. 

 How do you know if a vapor intrusion product is suitable for your specific site conditions? Once it is known what contaminants are on the redevelopment project, it is important to determine if the vapor barrier being evaluated is suitable for the specific levels of VOCs at the site. The product representative should be able to provide testing data to estimate how a product is likely to perform for the site.  

This interaction also points to another facet of responsiveness key to product selection: does the product supplier provide responsive support from design through construction? Time is money—if you’re working with a product that has a responsive team behind it, you could save both. 

drago-wrap-install

Achieving Effective Installation of Vapor Intrusion Barriers 

Proper installation is crucial for protecting buildings from vapor intrusion and moisture-related damage. To achieve this, it is essential that the manufacturer plays a proactive role by providing comprehensive support throughout the installation process. This includes organizing a pre-construction meeting to address project-specific conditions and outline best practices. Additionally, offering advanced product installation training helps ensure that installers are well-versed in the latest techniques and product specifications. Ongoing technical support is also vital to assist with any challenges that arise during the installation. Together, these measures help ensure that the vapor barrier meets industry standards and performs effectively under the unique conditions of each project. 

Cost-Effectiveness: The Strategic Value of Choosing the Right Vapor Intrusion Barrier

Price tags are easy to read. But responsiveness and flexibility, as detailed above, can play directly into the cost-effectiveness of any product solution. 

By choosing a solution that balances performance with affordability, developers and property owners can achieve long-term protection without overspending. Additionally, a cost-effective vapor intrusion barrier, like Drago Wrap®, can make compliance with environmental regulations more manageable, enhancing the overall value and safety of the property. Thus, investing in an economical yet reliable vapor intrusion barrier is a smart choice that promotes both fiscal responsibility and environmental stewardship. 

vapor-intrusion-barrierA Critical Component in Combating VOCs 

Brownfield redevelopment requires some of the most intense due diligence of any type of design. The human health, liability, and profitability impacts of construction on contaminated sites raise the stakes dramatically. 

Product selection is key to this due diligence. A properly installed, high-performance vapor intrusion barrier, along with the right product selection, is a critical component in combating VOCs, providing a safer, healthier environment for the building’s occupants. 

Product Assurance: Life of the Building Warranty 

Does the company stand behind their products? In the world of construction, confidence in product longevity and performance is paramount. Stego stands out by offering a comprehensive Life of the Building™ Warranty for its vapor barriers and retarders, reflecting the durability and reliability of our materials. When selecting vapor barriers and retarders, it's beneficial to consider products backed by such extensive warranties, providing peace of mind to developers and property owners, knowing that their investment is protected. 

 

New Call-to-action


 

 

Page Cotton

Written by Page Cotton

Page Cotton is the National Product Manager for Drago Wrap and Stego Wrap. Since 2005, he has had experience educating the industry about the effects of the below-slab environment on building health and its inhabitants. Page enjoys working as a trusted consultant to architects, engineers, and contractors to further their understanding of sub-slab barrier systems.

Drago, Drago-Awareness

Post Comments

To Request a sample or Literature
Click Here
Search our Product
Stego Industries

Have questions? We're here to help.

1-949-257-4100

Thank yo