They come in the same cartridge, look identical in the tube, and both are silicone. But structural sealant and weatherproof sealant perform fundamentally different jobs. Mixing them up is the most common specification error in curtain wall projects — and the most expensive one.
The Core Difference
| Structural Sealant | Weatherproof Sealant | |
|---|---|---|
| Primary job | Transfer structural loads between glass and frame | Keep water and air out of the joint |
| Typical standard | GB 16776-2005 (structural glazing) | GB/T 14683-2017 (building sealants) |
| Design strength | High — engineered adhesive bond | Not load-bearing |
| Movement capability | Class 25-50 | Class 20-35 typical |
| Application | Structural glazing, IGU secondary seal, panel bonding | Expansion joints, perimeter sealing, facade joints |
Why It Matters
Using a weatherproof sealant where a structural one is required means the glass panel is not actually bonded to the frame — a wind load or thermal movement event can detach the panel. Using structural sealant everywhere instead inflates cost and can over-constrain joints that need to move freely.
Products That Match the Two Roles
Structural role — our 8000 structural silicone sealant (GB 16776-2005) and 8800 structural sealant with ±35% movement and 20+ year service life.
Weatherproof role — the 8700 curtain wall weatherproof sealant and 8600 high-performance neutral weather-resistant sealant.
Specifier Checklist
- Does the joint transfer structural load? → Structural sealant.
- Is it a movement joint or perimeter seal? → Weatherproof sealant.
- Check the project standard: structural glazing projects cite structural silicone standards; facade sealing cites weatherproof sealant standards.
- Never substitute without the facade engineer’s approval.
Distributors and facade contractors can request batch test reports and compliance certificates for both product families from our team.
📧 info@sikenshop.com | 📱 +86 137 8087 6997 | 🌐 https://sikenshop.com
