A cement frame is a window construction in which glass blocks are set into a framework of reinforced cement or concrete. The cement frame combines light transmission with structural strength and is commonly used where both privacy and natural daylight are desired.
Construction and structure
A cement frame consists of a grid structure made from cement mortar or fine-grained concrete, into which glass blocks are placed. The construction is typically reinforced with steel bars or reinforcement mesh embedded in the horizontal and vertical joints. This gives the assembly the necessary strength and rigidity.
The glass blocks are usually square, with common dimensions of 19 by 19 centimetres or 24 by 24 centimetres and a thickness of 8 to 10 centimetres. They are manufactured by fusing two pressed glass halves together, creating a hollow, airtight space that provides a degree of thermal insulation.
The joints between the glass blocks are wider than those of a standard window, typically 10 to 20 millimetres, and are filled with cement mortar. Reinforcement is embedded in the mortar to prevent cracking and to strengthen the overall construction. The entire cement frame is installed as a fixed, non-opening element within the facade opening.
Application
Cement frames have traditionally been widely used in commercial and industrial buildings but also appear in residential construction. Typical applications include:
- Stairwells and corridors where daylight is desired but visual privacy is needed
- Bathrooms and sanitary areas
- Basements and cellars that benefit from natural light
- Facades of industrial buildings and workshops
- Partition walls in commercial spaces
The cement frame was particularly popular from the 1930s through to the 1970s. Although its use has declined with the advent of modern glazing systems, the cement frame remains valued in architecture for its distinctive character and is regularly used in the renovation of heritage buildings.
Related terms
- Glass block
- Glass brick
- Daylighting
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