CA C39 Roofing Contractor Exam

CA C39 Roofing Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• Which of the following roofing materials is most resistant to fire?
• Wood shingles
• Asphalt shingles
• Metal roofing
• Composite shingles

Metal roofing is non-combustible and provides superior fire resistance compared to other common roofing materials.

• What is the standard slope for residential asphalt shingle roofs?

A. 1:12

B. 2:12

C. 4:12

D. 6:12

A 4:12 slope (rise of 4 inches for every 12 inches of run) is typical for

asphalt shingle installation.

• What is the primary purpose of a roof underlayment?
• Improve insulation
• Provide a secondary water barrier
• Add structural strength
• Reduce UV exposure

Underlayment acts as a secondary barrier to prevent water infiltration if the primary roofing material fails.

• Which type of roof is designed to allow water to flow off in multiple

directions?

• Gable 1 / 3

• Shed
• Hip
• Flat

A hip roof slopes on all four sides, allowing water to drain in multiple directions.

• What is the primary function of flashing on a roof?
• Support the roof deck
• Provide insulation
• Prevent water penetration at joints
• Enhance aesthetic appeal

Flashing seals roof joints, penetrations, and intersections to prevent water leakage.

• Which of the following is the most important safety equipment for roof

work?

• Hard hat
• Gloves
• Fall protection harness
• Work boots

Fall protection is critical because falls are the leading cause of roofing injuries and fatalities.

• What is the maximum spacing recommended for roof trusses?
• 12 inches
• 16 inches
• 24 inches
• 36 inches

Roof trusses are typically spaced 24 inches on center to meet most residential building codes.

• Which roofing material is most suitable for flat roofs?
• Asphalt shingles
• Built-up roofing (BUR)
• Wood shakes
• Metal panels

Built-up roofing and similar membrane systems are designed for low- slope or flat roofs.

• What is the recommended minimum roof slope for single-ply

membrane roofing?

A. 0.5:12 2 / 3

B. 1:12

C. 1/4 inch per foot (approx. 1:48)

D. 2:12

Single-ply membranes can be installed on very low slopes; building codes often require a minimum of 1/4 inch per foot for drainage.

• What is the main cause of ice dams on roofs?
• Heavy rain
• Poor insulation and heat loss
• Low slope
• Improper flashing

Heat escaping from the interior melts snow, which refreezes at eaves, forming ice dams.

• When installing shingles, how much overlap is generally

recommended per course?

• 1 inch
• 2 inches
• 3 inches
• 4 inches

A typical three-inch exposure ensures proper water shedding and wind resistance.

• Which type of roof ventilation helps prevent moisture buildup in

the attic?

• Ridge vents
• Soffit vents
• Combination of ridge and soffit vents
• Gable end vents only

A continuous airflow from soffit to ridge prevents condensation and prolongs roof life.

• What is the minimum gauge of nails for asphalt shingles?
• 8 gauge
• 10 gauge
• 11 or 12 gauge
• 14 gauge

11 or 12 gauge nails provide adequate holding power without splitting shingles.

• How often should a typical residential roof be inspected?
• Every month
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