CSLB C-39 Roofing ContractorEstimating and PlanningHard
A sidewall where a roof meets a vertical wall measures 24 feet long. Standard 3-tab shingles are installed with a 5.625-inch weather exposure, and one step flashing piece is required at each course along the wall. How many step flashing pieces are needed?
- A52 pieces
- B58 pieces
- C48 pieces
- D43 pieces
Show answer & explanationAnswer & explanation
Correct answer: A. 52 pieces
Converting the wall length to inches gives 24 ft × 12 = 288 inches. Dividing by the 5.625-inch exposure per course: 288 ÷ 5.625 = 51.2, which rounds up to 52 pieces since a full flashing piece is needed at each shingle course, including the partial final course.
Why the other options are wrong
- B. Incorrect: overestimates beyond the calculated course count.
- C. Incorrect: does not match the exact division of wall length by exposure.
- D. Incorrect: undercounts the number of shingle courses along the wall.
Step Flashing Takeoff
Step flashing quantities are determined by dividing the sidewall length by the shingle weather exposure, since one piece is installed at each course.
- One step flashing piece is required per shingle course along a sidewall
- Convert wall length to inches before dividing by exposure
- Round up to ensure the final partial course is fully flashed
Memory trick: Every course needs its own little L-shaped guard.