PAINTSQUARE BLOG

From heavy hail and rainfall to sleet, snow, heat and general wear and tear, buildings can be subject to a wide range of extreme conditions, which makes them vulnerable to deterioration. Across the building envelope, specifying the right materials can be the difference between a successful project that performs well into the future, and a building with a short lifespan and poor functionality.

The same principles apply when choosing Air and Water Resistive Barriers (AWB).

With several types of AWBs on the market, making the right decision can be complicated. They each have their own characteristics, which could impact their suitability for certain projects.

In this article, Errol Bull, Technical Director for GE branded silicones, explores the different types of AWBs — with a particular focus on the benefits of fluid-applied AWBs. Read on to discover how different AWBs perform in varying environments and why fluid-applied AWBs are rapidly becoming the top choice among contractors and architects alike.

A Closer Look: Air and Water-Resistive Barriers

AWBs are integral to many projects, especially those with open-joint cladding designs.

All Photos: Courtesy of the Author

With several types of AWBs on the market, making the right decision can be complicated. They each have their own characteristics, which could impact their suitability for certain projects.

Due to its aesthetic appeal, open-joint cladding is becoming a more common design choice for exterior facades. It can help enable architects to bring their creative vision to life, creating contemporary buildings that boast clean lines, modern features and a highly aesthetic finished look.

However, open-joint cladding systems may have performance drawbacks in addition to their aesthetic advantages. This design choice can potentially expose the exterior wall to the elements, including snow, water, wind, rain and UV rays. This makes the building more vulnerable to water ingress, which can lead to mold, mildew and rot within the wall cavity.

In addition to shortening the building’s total lifespan, this vulnerability can pose a variety of issues to many groups, from architects and contractors to building owners and tenants. The right AWB can help protect against water infiltration, while allowing the building to breathe. This helps to increase its durability and performance, and minimizes the need for maintenance and repairs.

The Different Types of Air and Water Barriers

There are three main types of AWBs on the market, each with their own performance characteristics.

Sheet Types

These self-adhesive “peel and stick” membranes are manufactured to help control air leakage and the movement of moisture. They are typically applied straight to the substrate to create a physical barrier.

There are three main types of AWBs on the market, each with their own performance characteristics.

Fluid-Applied

These are typically easily applied using sprayers, brushes or power rollers. This helps to enable a more seamless installation and a tighter seal, especially around joints and penetrations. Fluid-applied AWBs are based on a few different chemistries, including acrylic and silicone.
Unlike sheet types, which rely on either limited adhesion or on mechanical attachment, fluid-applied systems are fully adhered to the substrate.

Fluid-Applied Vapor Permeable

Fluid-applied, permeable air barriers are applied in the same way as fluid-applied systems. The key difference is that they typically allow the building to breathe and water vapor to escape. Additionally, these barriers help to provide substantial protection for a wide selection of applications, as they are applicator friendly and fast curing. They maintain flexibility, even at low temperatures.

Fluid-Applied AWBs: Silicone vs Alternative Chemistries

With so many solutions on the market, and so many different chemistries to choose from, knowing which one to use can be difficult. So how does one choose solutions that will last the test of time?

In 1983, we started a 30-year test to evaluate the long-term durability of a variety of sealant types and to ascertain which performs best.

After 30 years, silicone sealants ranked higher than alternative chemistries for most of the above criteria.

With so many solutions on the market, and so many different chemistries to choose from, knowing which one to use can be difficult.

In sealants durability to weathering, silicone sealants ranked higher than polyurethane and acrylic terpolymer, and the silicone performed best of all for flexibility and toughness. With one exception, the silicone also showed the least % change in hardness.

The test showed that the sealants were stronger, more flexible and more resistant to extreme weathers — making them the obvious choice for most construction projects that need to perform and last well into the future.

All Environments. All Projects.

The right AWBs should withstand extreme temperatures and conditions, and some perform better than others in particular conditions. For example, projects based in cold landscapes benefit from silicone, fluid-applied, vapor-permeable AWBs due to their flexibility even at very low temperatures.

For buildings in hot, dry and sunny climates, UV-resistance is more important. For these applications, choosing a silicone-based AWB coating will ensure that it does not degrade over time.

Budget and deadline also play a significant role in deciding on which AWB to use. For projects that needed to be completed quickly, fluid-applied vapor permeable AWBs have significant performance advantages due to their quick application methods. A product such as Elemax AWB can be applied to a variety of substrates without the need for a primer. Elemax AWB also has the advantage that contractors can apply it in stages. After application, it can be left exposed. Contractors can return to projects typically weeks or months later to complete application without impacting performance.

Fluid-applied vapor permeable AWBs are also fast drying and usually become rain ready very quickly. This makes them a practical choice for contractors working during wet periods.

Introducing Elemax Air and Water Resistive Barrier Coating

Identifying the right AWB for a project depends on a myriad of factors, including everything from budget to the environment.
Elemax 2600 AWB is a 100% silicone air and water resistive barrier used to help control the flow of air and water through your building. Whatever the weather, this product works to help ensure that your building is energy efficient and protected from all the elements.

Identifying the right AWB for a project depends on a myriad of factors, including everything from budget to the environment.

Great results can be achieved with just one coat, with no primer required. When correctly applied, it quickly cures to form a durable membrane that is UV-resistant, vapor-permeable, and airtight, maintaining its elasticity even after years of exposure to extreme weather and temperatures.

Elemax AWB coating has been successfully used on countless construction projects across the U.S. and around the world, including on the SoFi Stadium. This flagship stadium required an Air and Water Barrier solution that could be used both with and without cladding. Additionally, the stadium wanted a solution that would not detract from its aesthetic appeal or be damaged by the high Californian temperatures and UV levels.

Elemax AWB was specified because of its 100% silicone-based formula and its inherent ability to withstand the elements while maintaining elasticity and performance after years of exposure to extreme temperatures.

Global Industry Leaders in Silicone for Building

The GE branded silicones portfolio is a global industry leader in silicone for building. It includes a range of solutions for the whole building envelope, comprising high quality sealants and coatings that are extending the life and enhancing the performance of all types of buildings across the world.

GE is a registered trademark of General Electric Company and is used under license by Momentive Performance Materials Inc.

Additional information about Elemax AWB coating and the GE branded silicone sealants and coatings can be found at  https://siliconeforbuilding.com/contact.

ABOUT THE THE BLOGGER Errol Bull, P.E., CSI - Architectural Engineer, Technical Services Manager Errol serves as the Technical Director for GE branded silicones. He received a Bachelor of Science in Architectural Engineering Technology from Boston’s Wentworth Institute of Technology in 1990, a Master of Science in Civil Engineering from Rensselaer Polytechnic Institute (Troy, New York) in 1992 and is a Licensed Professional Engineer in the state of New York. Errol provides technical support based on 18 years of global experience in construction sealants, adhesives and coatings. He is technically knowledgeable in the field of structural glazing, sealant physical properties and performance. SEE ALL CONTENT FROM THIS CONTRIBUTOR