In the context of modern architecture, the term spandrel describes the area filling the space between the head of the window in one story and the sill of the window in the story above. It can be thought of as the “span” between the vision areas on a building.
The single most sought after feature of all modern spandrel material is the ability to mask the underlying construction from view while presenting a finished surface to the exterior. Solid cladding material such as stone or metal panels provided smooth, polished or decorative relief. By their nature of being solid and opaque, masking underlying construction is assured. Designers seeking artistic contrast or seamless façade with windows or vision glass often turn to that material for their spandrel choice.
Glass has the unique characteristic of being both solid and transparent providing the illusion of nothing while maintaining the integrity and safety of the built environment. Using modern process glass can be colored, shaped, laminated, heat treated and coated with a variety of materials to alter basic characteristics.
There are a number of methods used to produce glass spandrels. The most common methods are firing of colored ceramic frit to the glass surface during the heat-treating process or the application of colored silicone elastomers. Product can be applied using spray, roll or curtain coating equipment.
The original transparency of the glass is altered after it is coated. The glass surface with the coating behind now becomes essentially opaque in reflection and exhibits a smooth monolithic surface in the color chosen. Combined with other glass in insulating units or applied directly to reflective or tinted reflective glass surfaces a myriad of choices are available. Trulite Glass & Aluminum Solutions produces both ceramic frit and silicone coated spandrel products.
As with any construction product, each coating type has strengths and weaknesses. Ceramic frits are not suitable for all colors or glass products. The thin translucent nature of the coated surface will show transmitted or reflected light from the spandrel cavity. For this reason, the coated or interior side is not usable as a finished surface and should always be enclosed or covered with other opaque back up materials. Careful review of the information provided here and consultation with your Trulite representative will ensure specifying the right material for your project.