What Is a Face Cap Curtain Wall? vs Structural Glazing
Face cap is the most widely used curtain wall system in Iran — but is it really the more sensible choice for your project compared with structural glazing? We compare the two on appearance, waterproofing, price and installation conditions.
A face cap curtain wall is a system in which the glass is held on all four sides by aluminum frames and decorative profiles ('caps') — the distinct horizontal and vertical lines you see from outside on a glazed facade. For the same reason it is also known as a 'capped' curtain wall.
In contrast, structural glazing (SSG) bonds the glass to the frame with structural silicone, and no cap is visible from the outside; the result is a seamless, all-glass surface. Its frameless version shows no frame even from the inside, and is used for lobbies, storefronts and luxury facades.
From the client's point of view, the practical difference lies on three axes. First, appearance: face cap expresses the regular lines of the architecture, while structural glazing creates a single uniform glass surface. Second, waterproofing: in a face cap system the water is managed inside the groove of the profile and drained back to the outside; in structural glazing, the quality of the silicone and the site supervision are critical. Third, cost and maintenance: face cap is usually more economical and its glass is easier to replace.
One common misconception: 'face cap is an old, low-quality system'. The reality is that quality depends on the execution details, the substructure principles, and the brand of profile and hardware — not on whether the cap is visible or hidden. Many landmark towers in Tehran have been built with face cap and have operated for years without any waterproofing problems.
Face cap profiles are produced in different thicknesses and shapes (flat, semicircular, triangular), and this flexibility allows the architectural form to be read — emphasized vertical lines or a uniform grid. The choice of profile must be checked at the same time as the facade height and the mullion spacing.
Summary of the choice: if the project budget is controlled, the building is tall and you want simple maintenance, face cap is the more logical choice; if a seamless all-glass look is the project's first priority and the budget and site supervision allow it, go for structural glazing. The technical catalog of the CW50 face cap system can be downloaded free of charge from the details library on our website — and if you are not sure which system suits your project, contact Namakaran Fakher Engineering Co. for a short technical consultation.