A curtain wall uses three different sealant functions: structural bonding to hold glass to the frame, weatherproof sealing to stop water and air infiltration, and — on some projects — fire-rated sealing for compartmentation. Selecting the wrong type for any of the three roles is a common and costly mistake. This guide walks through the selection logic.

1. Structural Glazing Sealant

Required wherever glass is bonded to the metal frame without mechanical fixing. Must comply with structural glazing standards (e.g. GB 16776-2005), have documented design strength, and a proven 20+ year track record. Our 8000 structural silicone sealant and 8800 structural sealant are the two grades we supply most for framed and semi-hidden curtain walls.

2. Weatherproofing Sealant

Used on expansion joints, perimeter seals and between panels. Key selection criteria: movement class (Class 20-35 for most facades), UV stability, and adhesion to glass, aluminum, stone and coated panels. See the 8700 curtain wall weatherproof sealant and 8600 high-performance weather-resistant sealant.

3. Movement Class — The Number Most Buyers Ignore

Movement capability (Class 25 vs 50) tells you how much joint movement the sealant absorbs. A Class 50 sealant handles double the movement of Class 25. Facades in seismic or high-wind regions should specify higher classes. Read our technical article on sealant movement capability for the full explanation.

4. Fire-Rated and Special-Purpose Sealants

Where fire compartmentation is required, use fire-rated silicone (e.g. our 119 fireproof flame-retardant silicone). Always confirm the local fire rating requirement with the facade engineer.

5. Packaging and Logistics

Curtain wall projects typically consume cartridges (300 ml) or sausages (590 ml), with bulk drums for factory glazing. All our curtain wall grades are available in OEM packaging and private label — see the sealant specification quick reference table for the full product matrix.

Need a project-specific recommendation? Send the project location, joint type and movement requirement — our technical team responds within 24 hours with grade, standard compliance and FOB pricing.

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