How a truss carries load
A truss uses triangles because a triangle cannot change shape without changing the length of a side. Loads on the roof travel through the top chords, webs and bottom chord to the supports.
Key parts
- Top chord: the sloped member under compression.
- Bottom chord: the horizontal member in tension, which resists spreading.
- Webs: diagonals and verticals that triangulate the frame.
- Plates: metal connectors that join members.
Why bracing matters
Most truss failures on site come from missing temporary or permanent bracing, not from the truss itself. Follow the engineer’s bracing plan.
Next: dimensions and load guide, how to build a truss and the load calculator.