Technical info
Structural Glazing System Types
There are many different types of structural glazing systems available. Common to all of these systems is that structural silicone sealant is used to structurally attach glass or another material to the building structure. Some of the more common types of systems are discussed in this section.

4-Sided Structural Glazing
4-sided structural glazing is the most common and usually most cost efficient type of structural glazing system used in European countries. Glass is supported on all four edges of the glass with structural silicone. 4-sided SG systems are typically fabricated in a production facility and erected at a jobsite.

2-Sided Structural Glazing
2-sided structural glazing systems use structural silicone on two of the four sides of the glass. The other two sides of the glass are either mechanically supported or are not structurally supported by a frame. 2-Sided SG systems are fabricated in a production facility or at the jobsite.

Slope Glazing
Slope glazing is when structural glazing is applied on a façade that is not vertical. Typical slope glazed SG systems are skylights. In such cases, the weight of the glass is considered in the SG joint dimensioning calculations. For slope glazing applications, European regulations require the use of laminated safety glass. Inverted slope glazing has also been used successfully on numerous projects.

Stepped Glass
Many SG systems install the SG joint on the internal surface of the outboard pane. In these systems, the insulating glass units are produced in a step fashion which allows glazing to the outboard pane. More traditional SG systems install the structural joint to the internal surface of the inboard pane of the insulating glass unit. Please refer to “Typical Structural Glazing Detail” on page 13 for an example of a typical stepped glass SG system.

Total Vision Systems
Total vision systems, which are commonly used at the front of a building to maximize vision area, use a glass fin to structurally support the vision glass. In such cases, the 2-sided SG system may use the structural silicone in shear from the glass edge to the glass fin.

Windload and Glass Dimension
The structural bite requirement is directly proportional to the windload on the building and the dimension of the glass. The higher the windload and the larger the dimensions of the glass are, the greater the amount of structural bite required. The controlling variables which affect the structural bite requirement are the maximum short span dimension of glass and the design windload that the structural glazing system must be designed to accommodate. The differential thermal movement between the glass and frame will impose upon the structural sealant joint a shear stress that must be considered during the design of the SG joint. The amount of differential movement will depend on the glass and metal (aluminium or stainless steel), maximum temperature change and design of the SG system. There will be greater movement if the aluminium frame is exposed to the exterior.

Substrates and Materials for Structural
Glazing Applications
It is important in the design of an SG system that the proper materials be used. Although Cemyapi requires approval of substrates and materials on a project by project basis, certain general recommendations can be provided during the design phase of the project.

Aluminium Profiles
Cemyapi works closely with most of the major aluminium profile manufacturers in Turkei to qualify their systems. Cemyapi  has an extensive database of adhesion testing to the profiles from these manufacturers. Aluminium profiles, whether anodized or painted with a polyester powder coating (PPC), must be of an architectural grade quality (QUALANOD or QUALICOAT).

Stainless Steel
Stainless Steel has been used successfully as a structural glazing substrate. The stainless steel must be of an architectural grade quality and should be submitted to Cemyapi for adhesion and compatibility testing.

Laminated Glass
Some laminated glass which utilizes polyvinyl butyral (PVB) may delaminate up to 6 mm when in contact with a neutral cure silicone sealant. This phenomenon is only an aesthetic concern and does not affect the performance of laminated glass in structural glazing applications. For specific compatibility results and recommendations, please refer to your laminated glass supplier..

Coated, Spandrel and Tinted Glass
There are many types of coated, spandrel and tinted glass materials available to the systems designer. There are many important considerations for the selection of glass. For more specific recommendations, please refer to the Europe Adhesion/Compatibility
Guide or contact your Cemyapi Technical Service Engineer. Following are a few of the general recommendations:

• Soft coating must be completely removed from all glass surfaces to receive structural silicone sealant. These coatings do not provide adequate strength and durability for long term stability of the structural bond. Soft coatings are often very difficult for silicone sealant to adhere to. Residual soft coating on the glass surface may cause sealant adhesion failure initially or after ageing (silver corrosion).
• Hard coatings are acceptable surfaces for structural glazing if these products have demonstrated long term stability and sealant adhesion has been verified through testing by Cemyapi.