Frameless Curtain Wall: Types, How It Works and Where It Fits

Search “curtain wall” and most results show grids of aluminum mullions. But a growing share of projects — hotel entrances, showrooms, airport landside facades, flagship retail — specify the opposite: a facade where the glass is the surface and the frame disappears. That is a frameless curtain wall.

This guide explains how frameless systems actually carry the glass, the three main ways they are built, where they fit, and what to check before you specify one. For how they sit alongside stick-built and unitized systems, see our guide to curtain wall system types.

What Is a Frameless Curtain Wall?

A frameless curtain wall is a glazed facade in which no conventional aluminum mullions or transoms are visible on the weather face. The glass panels themselves form the outer skin.

That does not mean there is no structure. The wind load still has to travel somewhere. Frameless systems move the support out of sight — behind the glass, through the joints, or into discreet fittings — so the exterior reads as one continuous glass surface with only thin joints between panels.

The Three Main Ways Frameless Walls Carry Glass

Spider Fittings and Point-Fixed Glazing

Each panel is drilled near its corners and held by stainless spider arms that bolt back to a supporting structure — steel fins, glass fins, or tension cables behind the glass. The fixings sit in small countersunk holes, so the outer face stays flat and uninterrupted. This is the classic spider-glazing look, common on entrances, atria, and canopy walls.

Structural Silicone Glazing (SSG)

In an SSG facade, the glass is bonded to an aluminum carrier frame with structural silicone instead of mechanical retaining beads on the exposed side. From outside you see glass meeting glass across a thin sealant joint; the metal is hidden behind. SSG keeps the weather face fully flat and is widely used on commercial curtain walls where a frameless look is wanted at scale.

Glass Fins and Cable-Supported Walls

Where the design wants maximum transparency, the aluminum is removed altogether: vertical glass fins or tension cables take the wind load, and the panels hang between them. These systems produce the most open elevations — long lobby walls, pavilions, atrium edges — but they are the most engineering-intensive of the three.

Where a Frameless Curtain Wall Fits

Frameless systems earn their cost where the glass itself is the message:

• Building entrances and lobbies
• Showrooms and flagship retail
• Airport, hotel, and cultural building facades
• Pool enclosures, pavilions, and garden rooms

For an honest comparison with ground-floor retail glazing and residential systems, see our guide to curtain wall vs storefront vs window wall.

Frameless vs Framed Curtain Wall: The Trade-Offs

What to Check Before Specifying

• Glass safety: frameless walls rely almost entirely on the glass itself. Fully tempered glass is the baseline; heat-soak testing screens panels for inclusions that can cause spontaneous breakage; laminated glass is specified where containment or overhead use demands it.
• Fittings and hardware: stainless spider fittings and counterplates; coastal or high-exposure sites should discuss marine-grade hardware with the supplier.
• Weathering: frameless does not mean unsealed. Two-stage drainage, gaskets, and sealant joints still have to be engineered, especially at heads, sills, and corners.
• Engineering review: deflection and anchor calculations should be run by a facade consultant or an experienced manufacturer — a guide to choosing one is here.
• Maintenance: agree the glass-replacement strategy (which panel comes out, from which side) before fabrication, and plan cleaning access for the finished wall.

Frequently Asked Questions

What is a frameless curtain wall?

A frameless curtain wall is a glazed facade with no visible aluminum mullions on the outer face. The glass panels form the surface, while hidden fins, cables, structural silicone, or discreet point fixings carry the wind load behind the glass.

Is a frameless curtain wall more expensive than a framed one?

Generally yes at the system level. Frameless walls need heavier glass, precision fittings, and more engineering per panel, while framed curtain walls use standardized aluminum profiles. The gap narrows on feature elevations where the frameless look is the design goal.

Is frameless glazing safe?

When specified correctly, yes. Panels use fully tempered glass, often with heat-soak testing to screen out inclusions that could cause spontaneous breakage, and laminated glass where containment or overhead use demands it. The key is a proper engineering review, not the frameless concept itself.

Can a frameless curtain wall cover a whole high-rise facade?

It can, but it is rarely the first choice. Wind loads grow quickly with height, so full-elevation frameless walls need substantial backing structure. Most projects use frameless systems at entrances, podiums, and lower floors, with framed curtain wall above.