The pitch of roof truss for Corrugated GI Sheets is kept between
- A1/3 and 1/6Correct
- B1/4 and 1/5
- C1/5 and 1/7
- D1/6 and 1/8
Solution
Concept
Pitch of roof truss for corrugated sheets
Formula
NONE
Step-by-step solution
1. The pitch of a roof truss depends on the roofing material to ensure adequate drainage of rainwater. 2. For corrugated galvanized iron (GI) sheets, the recommended pitch is generally between 1/3 and 1/6. 3. Steeper slopes are required compared to slate or tile roofing to prevent leakage at sheet laps. Answer: A
Explanation
The pitch of a roof truss represents the ratio of its total rise to its total span. For roofs covered with corrugated galvanized iron sheets, a pitch between 1/3 and 1/6 is required to allow efficient drainage of rainwater without letting wind lift the sheets. This ensures both waterproofing and structural stability under varied weather conditions.
Why the other options are wrong
B) A pitch of 1/4 to 1/5 is typically used for asbestos cement sheet roofing. C) A slope between 1/5 and 1/7 is flatter than required for corrugated GI sheets. D) A pitch between 1/6 and 1/8 is insufficient to ensure proper rainwater drainage on GI sheets.
Shortcut
Pitch of roof truss for Corrugated GI Sheets ranges between 1/3 and 1/6.
Common mistake
Confusing pitch requirements for corrugated GI sheets with those for AC sheets or other roofing materials.
Correct answer: A) 1/3 and 1/6