Structural Glazing — How a Frameless Glass Facade Actually Holds Together
The Facade With No Visible Frame
Drive past a new commercial tower in Airport City or the CBD and you will see the look everyone wants: a smooth, uninterrupted plane of glass with no aluminium grid breaking it up — just glass, reflection and shadow lines. That is structural glazing, and the question it raises is a fair one: if there is no visible frame holding the glass, what is holding the glass? The honest answer surprises people. The silicone is. Not as a sealant doing a small weatherproofing job, but as an engineered structural adhesive carrying real load. Understanding that is the difference between a facade that lasts decades and one that should never have been built. We engineer and install these systems, and this is how they actually work.
How Structural Glazing Works
In a conventional curtain wall, the glass sits captured inside an aluminium frame — you can see the metal pressure plates holding each pane. In structural glazing, some or all of those visible captures are removed and the glass is bonded to a carrier frame behind it with a structural silicone.
Two-Sided vs Four-Sided
- Two-sided structural glazing bonds the glass on two opposite edges and retains visible captures on the other two — a partial frameless look.
- Four-sided structural glazing bonds the glass on all four edges, so from outside there is no visible frame at all — the fully seamless plane.
The more sides that are bonded, the more the silicone is doing and the more critical the engineering and the workmanship become. This is the heart of our structural glazing work.
The Silicone Is Structural
This is the point that matters most. The structural silicone in a glazed facade is not bathroom sealant. It is a specified structural-grade silicone with a known strength, applied to a precisely prepared and cleaned surface, at a controlled bead size, and given proper cure time. It transfers wind load from the glass into the carrier frame and the building. Get the surface prep wrong, the bead size wrong, or the cure wrong, and you have a glass pane held on a tower by an adhesive that was never given the conditions to reach its strength. That is why this work is engineered and documented, not improvised on site.
Why the Engineering Is Not Optional
A frameless facade is exposed to the full wind load on a tall elevation, positive and negative, and the glass weight is permanent dead load. The structural silicone bite — the bead dimension bonding glass to frame — is calculated against those loads, not chosen by eye. We design the system, size the silicone bite to the wind and dead load, and verify the glass build-up (laminated, toughened, or a sealed insulated unit) for safety and performance.
The performance is held to real standards:
- ASTM E330 — structural performance of the glazed facade under positive and negative wind load
- ASTM E331 — water penetration of the facade under static pressure
- ASTM E283 — air leakage of the system
- AAMA 501 — the recommended methodology for field-testing an installed curtain-wall and glazed facade for air and water performance, so the finished wall is verified, not assumed
- EN 1090 — execution of the aluminium structure behind the glass, to the relevant Execution Class
Where the facade carries cladding panels alongside glass, we coordinate the glazing with the commercial cladding so the whole envelope performs as one system.
Where Structural Glazing Is Right — and Where It Is Not
Structural glazing is the right call for a premium commercial tower, a corporate headquarters or a hospitality landmark where the seamless look is part of the brief and the budget supports doing it properly. It is the wrong call as a way to save money on a frame, because the engineering, the structural silicone, the controlled application and the field testing make a correctly done structural-glazed facade a serious specification, not a shortcut. We will tell you honestly when a captured curtain wall would give you most of the look for less risk, and when the frameless plane genuinely justifies the structural-glazing route.
What Drives the Cost
- The glass build-up — laminated, toughened, single or insulated units for thermal and acoustic performance
- The number of bonded sides (two-sided vs four-sided) and the silicone-bite calculation
- The wind load on the elevation, which sets the structural design
- Field testing to AAMA 501 where the facade performance is verified on the building
- Access and height for installation on a tower
A structural-glazed facade is quoted on the engineered design, on survey. We never quote the lowest number; we quote a facade that is engineered to stay on the building, and we say plainly when a simpler system serves you better. Every installed facade carries our decade warranty on the workmanship.
Engineer It Properly From the Start
If you are specifying a frameless or near-frameless glass facade for a commercial or hospitality building, bring us in at design stage. We will engineer the silicone bite, specify the glass, and plan the field testing so the seamless look is matched by seamless performance.
Call Aluminium Installers Ghana on +233 27 011 3728 to engineer your glazed facade.