LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
in General by (30.0k points)
closed by
The economical range of spacing of roof trusses is:
1. \(\frac{1}{2}{\rm{\;to}}\frac{1}{3}{\rm{\;}}\)of span
2. \(\frac{1}{2}{\rm{\;to}}\frac{1}{4}\)of span
3. \(\frac{1}{4}{\rm{\;to}}\frac{1}{6}\)of span
4. \(\frac{1}{3}{\rm{\;to}}\frac{1}{5}\)of span

1 Answer

0 votes
by (53.7k points)
selected by
Best answer
Correct Answer - Option 4 : \(\frac{1}{3}{\rm{\;to}}\frac{1}{5}\)of span


For economical spacing of truss,

The cost of the truss should be equal to twice the cost of purlins plus the cost of roof covering.

t = 2p + r


t = cost of truss, p = cost of purlin, r = cost of the roof.

However, the above expression is used to check the spacing of the roof truss.

It can not be used to design the spacing as spacing does not occur in the equation.

As a guide, the spacing of roof trusses can be kept 1 / 4 of the span up to 15 m and 1 / 5 of span for 15 - 30 m spans of roof trusses.

∴ Option 4 is most appropriate 

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.