Sealants, Gaskets & Glazing Methods
Silicone sealants, structural silicone glazing, wet glazing, dry glazing, tape glazing, and pre-formed gaskets.
- Identify the primary sealant types used in glazing and their applications
- Explain structural silicone glazing requirements and limitations
- Distinguish between wet, dry, and tape glazing methods
- Describe gasket materials and their selection criteria
- State the compatibility requirements for sealants and glazing materials
Leçon 1
Sealants & Structural Silicone Glazing
Sealant Types
Sealants in glazing serve two critical functions - creating a weatherproof seal and accommodating movement between the glass and frame. The primary sealant types used in commercial glazing:
Silicone Sealant
Flexibility: Excellent - high movement capability
UV resistance: Outstanding
Temperature range: -65F to 400F
Adhesion: Excellent to glass
Paintable: No (most formulations)
Polyurethane Sealant
Flexibility: Good movement capability
UV resistance: Moderate (needs protection)
Temperature range: -40F to 180F
Adhesion: Good to most substrates
Paintable: Yes
Structural Silicone Glazing (SSG)
Structural silicone glazing uses silicone sealant as the primary attachment method for glass to the frame. The silicone structurally bonds the glass to the mullion, eliminating or reducing visible exterior framing. This creates a smooth, flush glass exterior.
SSG Requirements
Structural silicone must be two-part (chemically curing), applied in controlled conditions, and the glass must be tested for compatibility with the specific sealant. One-part silicone is not acceptable for structural applications.
Sealant Compatibility
Before applying any sealant, compatibility testing must verify that the sealant adheres properly to all contact surfaces and does not react with other materials. Incompatible sealants can:
- Fail to adhere (resulting in leaks)
- Stain or etch the glass surface
- React with spacer sealants in IGUs
- Cause premature seal failure
Silicone is the primary glazing sealant due to UV resistance and flexibility. Structural silicone glazing uses two-part silicone to bond glass to frames for a flush exterior. Always verify sealant compatibility with all contact surfaces before application.