Last year, Momentive National Structural Glazing Manager, Doug Walker, was featured in an article in USGlass Magazine to explain.  

In this blog, we expand on the topic, looking at how and why silicone sealants are used in glazing, and the factors you need to consider when choosing silicone sealants for insulating glass, structural glazing and weathersealing applications.
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How Silicone is Used In Glazing

There are four main types of silicone sealants used for glass applications in the construction industry:
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Vedantes para vidros isolantes

Silicone sealants, like EdgeSil™ Insulating Glass Sealants, are used as the secondary sealant in the insulating glass unit (IGU) edge seal, to bond glass lites and spacers together and support the integrity of air or gas filled insulating units.

Structural Glazing Sealants

Sealants, like UltraGlaze™ Structural Silicone Glazing Sealants, are used to create a strong and durable bond in glass curtain walls, window walls and glass facades, as well as protective glazing systems. They seal out extreme weather, while providing a resilient bond between the glass and the substrate.  

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Selantes Weatherseal

Weatherseal sealants, like SilPruf™ Weatherseal Sealants, are used to prevent air and water ingress around windows, sealing out the elements. They are also used to provide a strong, waterproof seal that secures glass to the frame.  

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Selantes para vidros residenciais

RapidStrength™ & SilGlaze™ II Residential Glazing Sealants are used in the creation of weatherproof window and door systems for homes. They are used for a variety of backbedding, sealing and joinery applications.  

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The Benefits of Silicone Sealants in Glazing

Silicone is used for a range of glazing applications for a number of reasons, including:
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Durability and performance

Our portfolio of silicone sealants offer resistance to temperature, weather, and UV exposure, providing long-lasting performance.

Once applied, they maintain a secure yet flexible bond for decades, with proven, long-term resistance to extreme temperatures, UV radiation, rain, snow, and wind with negligible change in strength and elasticity (we have a 30-year real world test to prove it!).

This helps to ensure that glazing systems and buildings last the test of time.  
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Adesão

Thanks to its chemical similarities, silicone sealant bonds really well to glass. This makes it a great candidate for creating a tight, seamless seal between the glass and the substrate – ensuring that it keeps everything secure while preventing air and water ingress.  

Many of our silicone sealants for glazing offer primerless adhesion to most substrates – this saves time and effort at every stage of the manufacturing and application process when compared to other sealants that may require a primer.  

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Permanent Flexibility

Buildings, and especially tall buildings, move a lot in the wind. Silicone sealants need to be able to stretch and remain flexible over time to accommodate this. Our range of silicone sealants have an excellent movement capacity, with high elasticity and tear resistance, so they can accommodate movement. This helps to protect glass panels, and the structure of the building itself.  

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Impact resistance

Silicone sealants are particularly well suited for protective glazing systems designed to withstand natural disasters, hurricane level winds, vandalism or bomb blasts.

During these events, one of the largest risks to building occupants is glass. When glass is blown from its frame, the shards have the potential to cause fatal injuries to people inside the buildings.

To prevent this, protective glazing systems are designed to reduce this risk, by preventing glass from being torn from the frames.  

UltraGlaze silicone structural glazing sealants offer the right combination of high tensile strength, high tear strength and high elongation capacity to achieve this. This allows them to withstand the forces involved without tearing. Instead, the sealant accommodates movement, which helps to absorb and dissipate the energy effectively.

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Building Supertall and Megatall

One of the biggest trends in contemporary global construction is the use of jumbo-glass, as architects look to secure sweeping city views in supertall and megatall skyscrapers. The goal is to create structures with more glass, and less metal.

The challenge is that as buildings get taller, the increasing wind pressures and larger glass panels typically require a larger silicone bite and wider mullions, which works directly against the design vision.  

Overcoming this challenge depends on having silicone sealants with improved strength, flexibility and better tear resistance. UltraGlaze SSG4600 sealant offers 30 psi (210kPa) tensile design strength.  

Check out our blog - Supertall to Megatall – Pushing Structural Glazing Boundaries with Silicone Technology for more.

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Silicone Sealant Selection

Choosing the right silicone glazing and glass sealants for your next project starts at the design phase – building engineers will be responsible for choosing the correct solutions, and determining things like the adhesive bite size and geometry for bonding silicones.  

We work closely with contractors, architects and construction engineers to provide adhesion, compatibility and performance reviews to ensure that the right sealants are used.  

When determining this, one of the most important factors is adhesive performance – especially in insulating glass and structural glazing applications. Establishing this depends on a few factors, including the substrate and any coatings applied to the glass that can impact on adhesive performance.  

Typically, this decision process can include product selection via a datasheet, or a consultation with a member of our technical team. If required, we can then run lab testing and site testing to ensure that the product will perform as expected.  

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Choosing the Wrong Sealants

Defective silicone sealants are very rare – and failures in insulated glass or structural glazing performance tend to be caused by poor system design, wrong product selection, lack of testing, inadequate surface preparation or application errors.  

Doug Walker, national structural glazing manager for Momentive explains:

“It’s like with most products – you need to choose the right products, store them properly and use them within their shelf life!”

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Silicone Sealants for Glass Applications

We offer a full range of high-performance silicone sealants for glazing applications, including:

• Vedantes de vidro isolante EdgeSil™

• UltraGlaze™ Selantes estruturais de silicone para envidraçamento

• Selantes SilPruf™ Weatherseal

For more information, visit our resource center, or connect with our team today.