SSG Curtain Wall Systems
The frameless glass facade. Hanart engineers structural silicone glazing (SSG) curtain walls — 2-sided and 4-sided — where glass appears seamless and the aluminum frame disappears. Clean sightlines, certified adhesion, engineered movement.
What is SSG curtain wall?
SSG curtain wall (structural silicone glazing) is a facade system in which glass panels are bonded to the aluminum frame with high-modulus structural silicone instead of mechanical caps. Because the load path runs through the silicone bead, the frame can hide completely behind the glass — producing the smooth, frameless, mirror-like facade seen on the world's most recognizable towers.
Hanart has delivered SSG and structural glazing facades since 1995, including landmark projects where the frameless aesthetic is the architectural signature. Our engineering team designs the silicone joint geometry from first principles — dead load, wind load, thermal movement, edge bite and sealant modulus — and validates every production batch by adhesion testing before it reaches the facade.
- Vision glass bonded with structural silicone, frameless appearance
- 4-sided SSG for completely seamless glazing panels
- Mechanical backup angles as mandatory safety net
- Batch silicone-glass adhesion testing on every project
2-sided, 4-sided and semi-SSG
The degree of structural bonding decides both the appearance and the engineering requirements.
2-Sided SSG
Glass structurally bonded on two opposite edges, with structural or wet-seal gaskets on the other two. The most economical SSG configuration and the standard for high-rise tower cladding.
- Clean horizontal bands with concealed glazing beads
- Simplified site logistics for repetitive tower panels
- Lower silicone stress than a 4-sided configuration
4-Sided SSG
Every edge of the glass is structurally bonded. The result is a completely frameless panel grid — ideal for atria, feature elevations and lobbies where pure glass is the design statement.
- Fully frameless vision, no visible caps
- Higher structural silicone demand, engineered joint geometry
- Enhanced thermal-break at the frame behind the silicone
Semi-Structural Glazing
A hybrid: structural silicone on the hidden drainage face, mechanical gaskets on the weather face. Balances the flat look of SSG with reduced structural glazing risk and simpler maintenance.
- Good frameless appearance with lower silicone exposure
- Common choice for stick-built systems
- Retrofit-friendly where caps are undesirable
Why SSG safety is an engineering discipline
A structural glass facade is only as safe as its weakest joint. Hanart's SSG quality program is built around verification at every stage.
Joint design & calculation
Every SSG joint is calculated for wind load, dead load, thermal movement and seismic drift. Edge bite, silicone width and thickness are derived from the sealant's certified design values, not by rule of thumb.
- Structural silicone sized per wind pressure & panel size
- Movement accommodation to ±10–15% joint width
- Glass edge bite and lamination schedule specified
Adhesion & compatibility testing
Structural silicone fails when it loses adhesion to the glass or frame. Hanart runs adhesion testing on every glass type, coating and sealant batch — with full-surface and H-tension peels — before, during and after the production run.
- Substrate compatibility on all sealed components
- UV and weathering exposure verification
- Field adhesion tests on installed panels
Mechanical safety backup
Good engineering assumes the silicone could one day be compromised. Hanart installs mechanical backup clips or angles on every SSG panel so the glass physically cannot fall — a redundancy our insurance and code reviews always support.
- Gravity clips on every panel edge
- Wind-load backup on 4-sided configurations
- Documented in the maintenance manual
Where frameless SSG shines
Commercial towers
2-sided SSG cladding dominates premium office towers: seamless glass bands, minimal visible framing and consistent reflectivity across the elevation.
- Unitized SSG panels for fast erection
- Vision plus fritted spandrel zones
- Coordinated with window washing anchors
Atria & lobbies
4-sided SSG turns an atrium into a glass box — no caps, no shadows, maximum daylight. Hanart coordinates the SSG with structural glass fins and point-supported fixing where spans grow large.
- Frameless lobby walls up to 4 m panels
- Glass fin reinforcement for tall spans
- Combined with skylight glazing above
Feature & curved facades
Cold-bent and curved SSG panels give free-form envelopes their seamless finish. The structural silicone accommodates the geometry while keeping the skin perfectly flush.
- Cold-bent SSG panels on free-form geometry
- Curved tempered glass with SSG bonding
- Parametric panel layouts coordinated in BIM
SSG curtain wall questions, answered
SSG stands for structural silicone glazing. In an SSG curtain wall, the glass is bonded to the aluminum frame with structural silicone — no mechanical caps or visible pressure plates — creating a smooth, frameless, glass-dominant facade. Structural glazing curtain walls are the standard for premium commercial towers.
Yes, when engineered correctly. Hanart designs SSG joints to international standards, runs adhesion testing on every glass and sealant batch, and installs mechanical backup angles as a safety net so the glass cannot fall even if the silicone were damaged. Our SSG facades are fully tested with full-scale mock-ups before fabrication.
In 2-sided SSG the glass is structurally bonded on two opposite edges with mechanical gaskets on the other two. In 4-sided SSG all four edges are silicone-bonded, giving a completely frameless appearance. 4-sided SSG is common for feature facades and atria; 2-sided SSG is the economical standard for tower cladding.
Yes. Hanart combines SSG panels with unitized framing, point-supported glazing, curved glass and daylighting systems on the same facade, with coordinated junctions engineered in BIM so the envelope reads as one continuous glass wall.
High-grade structural silicone has a proven service life of 25-40+ years in curtain wall applications when installed with correct joint geometry, primer and quality control. Hanart specifies premium silicone systems with documented durability data, and offers periodic sealant inspection in our aftercare service.
Engineer a frameless SSG facade
Send your drawings and design intent. Hanart will assess the SSG configuration, silicone joint design and budget within 24 hours.