Queen Post Roof Truss is suitable for spans ranging from
- A6.0 to 9.0 m
- B9.0 to 13.5 mCorrect
- C13.5 to 18 m
- D> 18.0 m
Solution
Concept
The queen post truss has two vertical queen posts. It is used for spans of about 9 to 14 m.
Step-by-step solution
1. King post truss: one central post, economical up to about 8-9 m span. 2. Queen post truss: two posts and a straining beam, suitable for about 9-14 m span. 3. Mansard and steel trusses are used for larger spans. 4. Among the options, 9.0 to 13.5 m matches the queen post truss.
Explanation
A queen post truss has two vertical posts joined by a straining beam. It covers larger spans than a king post truss, about 9 to 13.5 m. Steel trusses are preferred for longer spans.
Why the other options are wrong
6-9 m: king post truss range. 13.5-18 m and >18 m: too large for a timber queen post truss. Combination or steel trusses are used here.
Shortcut
King post up to 9 m, queen post 9-14 m.
Common mistake
Mixing up the span ranges of king post and queen post trusses.
Correct answer: B) 9.0 to 13.5 m