CSLB C-39 Roofing ContractorSteep-Slope RoofingHard
A roofing crew is installing 16-inch wood shakes on a roof with a 7:12 slope. They are using a single-coverage application, which is less common but specified for this project. What would be the maximum recommended exposure for these 16-inch wood shakes in a single-coverage application on this slope?
- A5.0 inches
- B8.0 inches
- C6.5 inches
- D7.5 inches
Show answer & explanationAnswer & explanation
Correct answer: D. 7.5 inches
For 16-inch wood shakes, typical maximum exposure is 7.5 inches in a single-coverage application. While single coverage is generally not recommended for steep-slope roofing due to reduced weather protection, the maximum exposure for a 16-inch shake is half its length (8 inches) minus a minimum headlap, or 7.5 inches as a standard maximum in single coverage.
Why the other options are wrong
- A. 5.0 inches is a common exposure for 16-inch shakes in a triple-coverage application, not single.
- B. 8.0 inches would be exactly half the shake length, leaving no headlap, which is not recommended for proper water shedding.
- C. 6.5 inches is too conservative for maximum exposure in single coverage for a 16-inch shake.
Wood Shake Single Coverage Exposure
The maximum visible portion of a wood shake when only one layer of shake covers the underlayment below, less common and with reduced weather protection.
- Less weather-resistant than double or triple coverage.
- Exposure is typically half the shake length minus a small headlap.
- Not generally recommended for primary roofing.
Memory trick: Single coverage, half the length, less for strength.