1. Rafter roof

This is the most common light gauge steel roof structure, mainly used for complex roof shapes.

The rafter roof can be divided into:

■Rafters and pillars (picture 1 and picture 2)

This is the most common LGS roof structure, mainly used for complex roof shapes.

Picture 1

Picture 2

■Rafters and restraint joists (pictures 3 and 4)

Picture 3

Picture 4

This kind of light gauge steel roof structure is relatively rare, and is mainly used for complex roof shapes where it is difficult to install pillars.The Tsinghua School built with Boxer indemnity in 1911 adopted a roof skeleton structure with rafters and restraining joists (Figure 3-5). This may be China's earliest and still existing balsa-frame building designed by North American architects (in the early morning of November 13, the Tsinghua School, built in 1911, caught fire, covering an area of approximately 3,000 square meters).

Picture 5

The Tsinghua Academy was designed and built 100 years ago, and its balsa-frame roof structure is basically the same as today’s balsa-frame roof structure. It has all kinds of structural components such as shear braces, rafters, ceiling joists, and restraint joists. In other words, more than 100 years ago, the technology of balsa frame construction was finalized and very mature.