CSLB C-39 Roofing ContractorSteep-Slope RoofingHard
A roofing inspector is examining a newly installed slate roof. The slates are 24 inches long, and the roof has a 6:12 slope. To ensure proper weather protection, what is the minimum required headlap for these slate tiles?
- A4 inches
- B5 inches
- C3 inches
- D2 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 3 inches
For slate roofs, the minimum headlap is determined by the roof slope. For slopes 4:12 to 8:12, a minimum headlap of 3 inches is required. The length of the slate (24 inches) influences exposure but not the minimum headlap directly once the slope determines the category.
Why the other options are wrong
- A. 4 inches is usually for lower slopes (e.g., 3:12 to 4:12) or specific slate types.
- B. 5 inches would be for very low slopes (e.g., 2:12 to 3:12), which are generally not recommended for slate.
- D. 2 inches is typically for steep slopes (over 8:12) with slate, not 6:12.
Slate Headlap Requirements
The shortest distance from the butt of a slate to the top edge of the slate in the second course below it, critical for water shedding.
- Determined by roof slope.
- Ensures water flows over two layers of slate.
- Longer headlap for shallower slopes.
Memory trick: Slope's the key, for headlap you see.