CSLB C-39 Roofing ContractorSteep-Slope RoofingEasy
A standard three-tab asphalt shingle measures 12 inches by 36 inches. What is the standard weather exposure used when installing these shingles on a typical steep-slope roof?
- A6 inches
- B5 inches
- C7 inches
- D4 inches
Show answer & explanationAnswer & explanation
Correct answer: B. 5 inches
A standard 12x36 three-tab shingle has three 12-inch-wide tabs, and the standard weather exposure recommended by manufacturers and referenced in roofing codes is 5 inches, leaving a 7-inch headlap for weatherproofing.
Why the other options are wrong
- A. 6 inches exceeds standard exposure and reduces headlap protection.
- C. 7 inches is far too much exposure and would expose fastener heads.
- D. 4 inches is less than standard and would waste material without added benefit.
Standard Shingle Exposure
The portion of a shingle left uncovered (visible) after installation, which determines headlap coverage.
- Standard 3-tab shingle: 12in x 36in, 5in exposure
- Exposure + headlap = shingle length minus overlap
- Manufacturer specs always govern actual exposure
Memory trick: Five for standard, always in fashion.