CSLB C-39 Roofing ContractorEstimating and PlanningHard
A two-person roofing crew can install 2.5 squares per hour on a straightforward gable roof. The job totals 32 squares of shingles. Based solely on the installation rate, how many labor hours should the estimator budget to complete the shingle installation?
- A11.2 hours
- B10.5 hours
- C14.4 hours
- D12.8 hours
Show answer & explanationAnswer & explanation
Correct answer: D. 12.8 hours
Divide the total squares by the crew's installation rate: 32 ÷ 2.5 = 12.8 labor hours.
Why the other options are wrong
- A. Results from an incorrect division or rounding error.
- B. Underestimates by using a rate higher than 2.5 squares per hour.
- C. Overestimates by using a rate lower than the stated 2.5 squares per hour.
Labor Hour Estimating
Labor hours for a roofing job are estimated by dividing the total roofing squares by the crew's installation production rate per hour.
- Labor hours = total squares ÷ squares installed per hour.
- Production rates vary by roof complexity and crew size.
- Estimators often add buffer time for tear-off, cleanup, and complexity.
Memory trick: Total squares divided by rate equals hours on the clock.