What is the main characteristic of a curtain wall?

The main characteristic of a curtain wall is that it does not support any weight from the building structure, except its own weight. Typically, a curtain wall is a non-structural cladding system that is attached to the building frame. Its primary purpose is to keep the weather out and to allow daylight into the building while providing a degree of aesthetic appeal.

This distinction is crucial in understanding architectural design, as curtain walls are designed to protect the interior spaces from external elements without bearing the structural loads from the floors or roof.

In contrast, the option describing it as self-supporting would not be accurate, as a curtain wall relies on the main building structure for support. Additionally, while curtain walls can be made from various materials, including glass, metal, and stone, they are not typically exclusive to bricks and mortar, and the statement claiming they can only be installed on the roof is incorrect, as they are commonly used on vertical surfaces of buildings.