What glue is used for glass curtain walls

As an important part of modern building exterior wall decoration, the sealing and bonding of glass curtain walls are crucial. So do you know what glue is used for glass curtain wall glue? What are its functions? Zhongdong Curtain Wall will take you to understand the role of glass curtain wall glue today.

Structural bonding: This is the most important and safety-related function. A specific type of glue (structural glue) permanently bonds the glass panel to the curtain wall frame (usually aluminum alloy profiles), bearing the self-weight, wind load, seismic load, etc. of the glass, and transfers it to the supporting structure. It replaces the traditional mechanical fixing method.

Weather-resistant sealing: An elastic sealing layer is formed at the joints between the curtain wall panels and between the panels and the frame, which effectively blocks the penetration of rain, air, and dust, ensures the waterproof, windproof, and airtight performance of the building, and improves the thermal insulation effect.

Displacement compensation: The curtain wall structure will produce displacement (expansion, shear, and torsion) due to temperature changes, wind pressure, earthquakes, and other factors. Sealant has good elasticity and displacement ability, can follow the deformation of the joint without cracking or debonding, and maintain the integrity of the seal.

Stress buffering: Absorb and disperse the stress caused by thermal expansion and contraction or load between different parts of the structure, reduce local stress concentration on the glass or frame, and prevent cracking or deformation.

Sound insulation and noise reduction: Well-sealed joints help reduce airborne sound transmission and improve the overall sound insulation performance of the curtain wall.

Aesthetic decoration: The color of the curtain wall glue usually matches the curtain wall system design to form a neat and smooth visual line.

Glass curtain wall glue is mainly divided into two categories:

1. Silicone structural sealant
Function: This is the lifeline of curtain wall safety. Specially used for structural bonding, glass, metal sub-frame, stone or other panels are directly bonded to the curtain wall support structure (main frame), bearing and transmitting various static and dynamic loads (self-weight, wind pressure, seismic force, etc.). It must have extremely high strength, excellent durability and long-term reliability.

Application location:
Glass and metal sub-frame (usually aluminum alloy) bonding (structural assembly).
Metal sub-frame and main frame (column, beam) bonding.
Glass and joint bonding in point-supported curtain wall.
Core bonding material for hidden frame and semi-hidden frame curtain wall.
Key characteristics requirements:
Extremely high tensile strength, shear strength and modulus.
Excellent anti-aging and weather resistance (UV, ozone, high and low temperature resistance).
Good elastic recovery and displacement capacity (usually requires ±25% to ±50%).
Excellent adhesion with curtain wall materials such as glass, anodized aluminum, stainless steel, etc.
Extremely low modulus change (to ensure long-term performance stability).
Common colors: black, gray, white, bronze, etc., to be selected according to design requirements.

2. Silicone weathering sealant
Function: Mainly used for weathering sealing of curtain wall joints. Fill the gaps between curtain wall panels (panel joints) and between curtain wall panels and building structures, provide long-term waterproof, airtight, and dustproof barriers, and can adapt to the displacement changes of joints. It does not bear structural loads.
Application location:
Horizontal and vertical joints (panel joints) between curtain wall unit panels.
Joints between curtain walls and other parts of the building such as parapets, window sills, roofs, etc.
Sealing around the opening fan.
As the outer layer protection of structural adhesive (sometimes a “double-channel sealing” strategy is adopted: inner layer structural adhesive + outer layer weathering adhesive).
Key feature requirements:
Excellent weather resistance (anti-ultraviolet, high and low temperature resistance, rain erosion resistance).
Good displacement capacity (usually ±25% to ±50%).
Long-lasting elastic recovery ability.
Good adhesion to curtain wall materials (glass, aluminum, coatings, stone, etc.).
Low pollution (avoid contamination of curtain wall surface).
Common colors: The color selection is very wide and needs to be coordinated with the curtain wall exterior design.

Other auxiliary adhesives/sealants

Fireproof sealant:
Function: Used in the gaps between the curtain wall and the building structure such as the floor slab, partition wall, or around the pipes that penetrate the curtain wall to provide fireproof sealing to prevent the spread of flames and smoke between floors or different fire partitions.

Insulating glass sealant:
Function: Specially used to manufacture insulating glass units. Including the first seal (butyl glue, the main function is to block water vapor) and the second seal (usually silicone glue or polysulfide glue, the main function is structural bonding and auxiliary sealing). This type of glue is not directly used for curtain wall structure assembly, but insulating glass is the main component of the curtain wall.

Stone silicone sealant:
Function: If the curtain wall contains stone panels, silicone sealants designed specifically for stone (including weather-resistant glue and structural glue) will be used. Special attention should be paid to its compatibility with stone (no pollution), permeability and special primer.

Summary and key considerations

Structural sealant vs. weathering sealant: Silicone structural sealant and silicone weathering sealant are the two most core and commonly used types of sealants for glass curtain walls. Structural sealants are about safety and are responsible for force bonding; weathering sealants are about functionality and are responsible for waterproof sealing. The functions of the two are not interchangeable!

Selecting and using the right glass curtain wall sealant is a key link in ensuring the safety, durability, functionality and aesthetics of the glass curtain wall.

Zhongdong Curtain Wall provides high-quality glass curtain wall system solutions. Whether you are looking for custom glass curtain walls or aluminum veneer curtain walls, our team will help you realize your vision. We will help you provide an ideal curtain wall system for your building’s exterior, combining architectural aesthetics with functionality. If you are interested in glass curtain walls or other curtain walls, please email us at monikachenwall@gmail.com, or call us at +86-17727814139, and we will arrange for customer service to contact you as soon as possible.