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? It is best to have a picture!

Hunan Yinhe Steel Structure Company will answer your question: Light steel structure has no upper chord and lower chord, only upper and lower flanges of steel beams. The diagonal member above the truss or roof truss of general 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 cross-shaped bracing parallel to the upper chord is called the horizontal bracing of the upper chord, the cross-shaped bracing parallel to the lower chord is called the horizontal bracing of the lower chord, the cross-shaped bracing vertically connecting two adjacent roof trusses is called the vertical bracing of the roof truss, and the cross-shaped bracing vertically connecting two adjacent columns is called the vertical bracing between columns.