Steel frame roofing method: The civil construction does not make a tic-shaped beam structure, but only leaves a rectangular, square or circular opening. According to the size of the opening and design requirements, there are generally two methods:

1. Light steel structure: This method is suitable for situations where the opening is small but cannot be made into a single lighting cover. According to the size of the opening, appropriate square tubes, I-beams, and channel steels are selected as light steel keels to support the roof structure.

There are two forms of practice:

①Light steel structure-split lighting cover method: This method divides the lighting opening into several independent openings and makes drainage gutters. As shown in the picture above right.

②Light steel structure-joint lighting cover method: This method is to divide the lighting cover into two or four (should not be too large) to form a common side beam in the middle without making a gutter. As shown on the right.