Residential Building Inspector B1Roof-Ceiling ConstructionHard
A residential building inspector is performing a final inspection of a roof covering. The roof has a pitch of 6:12 and is covered with concrete tiles. What is the minimum required overlap for the concrete tiles?
- A2 inches
- B5 inches
- C3 inches
- D4 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 3 inches
According to IRC Table R905.3.6, for concrete or clay tiles on a roof with a pitch of 4:12 or greater, the minimum headlap required is 3 inches. If the pitch were less than 4:12 but not less than 2 1/2:12, a 4-inch headlap would be required.
Why the other options are wrong
- A. 2 inches is too small for concrete tiles.
- B. 5 inches is not a standard minimum headlap for concrete tiles.
- D. 4 inches would be required for pitches between 2 1/2:12 and 4:12, not 6:12.
Concrete/Clay Tile Headlap
The shortest distance from the lower edge of an overlapping tile to the upper edge of the tile in the second course below it, crucial for weather protection.
- Minimum 3 inches for pitches ≥ 4:12.
- Minimum 4 inches for pitches between 2 1/2:12 and < 4:12.
- Not permitted for pitches less than 2 1/2:12.
Memory trick: Tiles need specific overlap; steeper means less, shallower needs more.