What is the difference between horizontal support and vertical support of steel structure roof? What's the difference between the top chord and the bottom chord?

Hunan Yinhe Steel Structure Company answers for you: Light steel structure has no upper chord and lower chord, only upper and lower flanges of steel beams. Generally, the diagonal member on the truss or roof truss of steel (called heavy steel) structure is called the upper chord, the horizontal member below is called the lower chord, and the short member connected between the upper and lower chords is called the web member.

The X-shaped support parallel to the upper chord is called the horizontal support of the upper chord, the X-shaped support parallel to the lower chord is called the horizontal support of the lower chord, the X-shaped support vertically connecting two adjacent roof trusses is called the vertical support of the roof truss, and the X-shaped support vertically connecting two adjacent columns is called the vertical support between columns.