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California Roofing Contractor Exam– COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
California Roofing Contractor (C-39)
SUMMARIZED EXAM TOPIC COVERAGE (Point Form)
• C-39 Classification (16 CCR §832.39) – Roofing contractor installs surfaces that seal, waterproof,
weatherproof structures using asphalt, pitch, tar, felt, glass fabric, foam, metal, shakes, shingles,
tile, slate, or membranes
• Exam Structure (CSLB) – Trade exam + Law & Business exam; computer-based, multiple choice
• Exam Content Areas (Approximate Percentages) – Planning & Estimating (22%), Job Site
Preparation (13%), Low-Slope Roof Projects (17%), Steep-Slope Roof Projects (26%), Safety
(22%)
• Roofing Math & Measurement – Squares (100 sq ft); area calculations (triangles, trapezoids,
circles); conversions (feet, inches, meters, mm)
• Steep-Slope Systems (≥4:12) – Asphalt shingles (min 4:12 standard, 2:12 with double underlay);
wood shakes/shingles (exposure, nailing, felt); clay/concrete tile (layout, hip nailing board set
back 10"); slate (overhang, nails); metal (standing seam min 2:12)
• Low-Slope Systems (<4:12) – BUR (built-up roofing, aggregate surfacing for UV protection);
modified bitumen (torch-down safety); single-ply (TPO, PVC, EPDM); cool roofs (Title 24, SRI
minimum 60)
• Flashing & Moisture Protection – Step flashing (roof-to-wall); valley flashing (11" from
centerline for shakes/slate, 8" for wood/metal shingles); cricket/diverter[9]; base flashing
fasteners[4]
• Underlayment & Felt – 15 lb felt (4 sq/roll); 30 lb felt; double underlayment for 2:12-4:12
slopes; lap requirements; felt on plywood decks (annular-threaded nails)
• Ventilation & Moisture Control – Attic ventilation ratio 1:150 (net free area); lightweight
insulating concrete venting; shake liners for waterproofing
• Structural & Deck Requirements – Minimum 28-day concrete cure; plywood/OSB thickness;
steel decks (mechanical fasteners + asphalt cementing for first ply); deflection limits (live load
300 lbs)
• Cal/OSHA Safety – Fall protection (>6 ft); ladder overlap (10%); high-voltage line clearance (6 ft);
hot asphalt buckets (6 gal max), mop buckets (9.5 gal max); roof jacks (top 5" under shingle)
• Roof Geometry Terminology – Pitch (rise/span); slope (rise/run); hip rafter, valley rafter,
common rafter, jack rafters; ridge, plate
• Codes & Standards – CBC references IBC with CA amendments; Title 24 energy (cool roofs)
250 RANDOM SCENARIO-BASED QUESTIONS (With Answers & Rationales)
1. A roofing contractor is preparing to install asphalt shingles on a residential home with a roof slope of
2:12. According to California Building Standards, what special requirement applies?
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A) Asphalt shingles are not permitted on slopes less than 4:12
B) Asphalt shingles are permitted on slopes as low as 2:12 provided double underlayment is used for
slopes between 2:12 and 4:12
C) Asphalt shingles may be installed with single underlayment
D) Only metal roofing is allowed on slopes less than 4:12
Answer: B – Asphalt shingles are permitted on 2:12 slopes with double underlayment; standard
application requires 4:12 or greater.
2. When calculating roofing materials for a 2,500 sq ft roof, how many squares of material must you
order?
A) 15 squares
B) 20 squares
C) 25 squares
D) 30 squares
Answer: C – One roofing square equals 100 square feet; 2,500 ÷ 100 = 25 squares.
3. What is the primary purpose of installing flashing on a roof?
A) To provide insulation
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B) To prevent water penetration at roof joints and penetrations
C) To add aesthetic value
D) To support the weight of shingles
Answer: B – Flashing diverts water away from roof joints, valleys, chimneys, and walls to prevent leaks.
4. A roofing contractor discovers dry rot in the plywood sheathing during a tear-off. What is the legally
required course of action?
A) Cover it with 30-lb felt and proceed
B) Notify the homeowner and replace the damaged wood before dry-in
C) Apply a wood sealer over the rot
D) Install a metal plate over the area
Answer: B – Roof coverings must be applied to a solid, structurally sound deck; rotted wood cannot
properly hold fasteners.
5. What is the minimum required slope for the installation of asphalt shingles on a residential roof under
standard conditions (without double underlayment)?
A) 1:12
B) 2:12
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C) 4:12
D) 6:12
Answer: C – Standard asphalt shingle application requires a minimum 4:12 slope to properly shed water.
6. A contractor is installing a new TPO roof on a low-slope commercial building. Which method is most
commonly used to secure the TPO membrane seams?
A) Solvent welding
B) Hot air welding (heat welding)
C) Adhesive bonding with contact cement
D) Mechanical fastening with batten bars
Answer: B – TPO seams are welded using hot air welding equipment, which fuses the overlapping edges
into a continuous waterproof membrane.
7. What is the purpose of the aggregate surfacing (gravel or slag) on a built-up roofing (BUR) system?
A) To provide structural reinforcement to the plies
B) To improve the R-value of the insulation
C) To protect the bitumen from ultraviolet (UV) degradation
D) To facilitate faster water drainage
California Roofing Contractor Exam– COMPLETE
QUESTIONS AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
California Roofing Contractor (C-39)
SUMMARIZED EXAM TOPIC COVERAGE (Point Form)
• C-39 Classification (16 CCR §832.39) – Roofing contractor installs surfaces that seal, waterproof,
weatherproof structures using asphalt, pitch, tar, felt, glass fabric, foam, metal, shakes, shingles,
tile, slate, or membranes
• Exam Structure (CSLB) – Trade exam + Law & Business exam; computer-based, multiple choice
• Exam Content Areas (Approximate Percentages) – Planning & Estimating (22%), Job Site
Preparation (13%), Low-Slope Roof Projects (17%), Steep-Slope Roof Projects (26%), Safety
(22%)
• Roofing Math & Measurement – Squares (100 sq ft); area calculations (triangles, trapezoids,
circles); conversions (feet, inches, meters, mm)
• Steep-Slope Systems (≥4:12) – Asphalt shingles (min 4:12 standard, 2:12 with double underlay);
wood shakes/shingles (exposure, nailing, felt); clay/concrete tile (layout, hip nailing board set
back 10"); slate (overhang, nails); metal (standing seam min 2:12)
• Low-Slope Systems (<4:12) – BUR (built-up roofing, aggregate surfacing for UV protection);
modified bitumen (torch-down safety); single-ply (TPO, PVC, EPDM); cool roofs (Title 24, SRI
minimum 60)
• Flashing & Moisture Protection – Step flashing (roof-to-wall); valley flashing (11" from
centerline for shakes/slate, 8" for wood/metal shingles); cricket/diverter[9]; base flashing
fasteners[4]
• Underlayment & Felt – 15 lb felt (4 sq/roll); 30 lb felt; double underlayment for 2:12-4:12
slopes; lap requirements; felt on plywood decks (annular-threaded nails)
• Ventilation & Moisture Control – Attic ventilation ratio 1:150 (net free area); lightweight
insulating concrete venting; shake liners for waterproofing
• Structural & Deck Requirements – Minimum 28-day concrete cure; plywood/OSB thickness;
steel decks (mechanical fasteners + asphalt cementing for first ply); deflection limits (live load
300 lbs)
• Cal/OSHA Safety – Fall protection (>6 ft); ladder overlap (10%); high-voltage line clearance (6 ft);
hot asphalt buckets (6 gal max), mop buckets (9.5 gal max); roof jacks (top 5" under shingle)
• Roof Geometry Terminology – Pitch (rise/span); slope (rise/run); hip rafter, valley rafter,
common rafter, jack rafters; ridge, plate
• Codes & Standards – CBC references IBC with CA amendments; Title 24 energy (cool roofs)
250 RANDOM SCENARIO-BASED QUESTIONS (With Answers & Rationales)
1. A roofing contractor is preparing to install asphalt shingles on a residential home with a roof slope of
2:12. According to California Building Standards, what special requirement applies?
, Page 2 of 105
A) Asphalt shingles are not permitted on slopes less than 4:12
B) Asphalt shingles are permitted on slopes as low as 2:12 provided double underlayment is used for
slopes between 2:12 and 4:12
C) Asphalt shingles may be installed with single underlayment
D) Only metal roofing is allowed on slopes less than 4:12
Answer: B – Asphalt shingles are permitted on 2:12 slopes with double underlayment; standard
application requires 4:12 or greater.
2. When calculating roofing materials for a 2,500 sq ft roof, how many squares of material must you
order?
A) 15 squares
B) 20 squares
C) 25 squares
D) 30 squares
Answer: C – One roofing square equals 100 square feet; 2,500 ÷ 100 = 25 squares.
3. What is the primary purpose of installing flashing on a roof?
A) To provide insulation
, Page 3 of 105
B) To prevent water penetration at roof joints and penetrations
C) To add aesthetic value
D) To support the weight of shingles
Answer: B – Flashing diverts water away from roof joints, valleys, chimneys, and walls to prevent leaks.
4. A roofing contractor discovers dry rot in the plywood sheathing during a tear-off. What is the legally
required course of action?
A) Cover it with 30-lb felt and proceed
B) Notify the homeowner and replace the damaged wood before dry-in
C) Apply a wood sealer over the rot
D) Install a metal plate over the area
Answer: B – Roof coverings must be applied to a solid, structurally sound deck; rotted wood cannot
properly hold fasteners.
5. What is the minimum required slope for the installation of asphalt shingles on a residential roof under
standard conditions (without double underlayment)?
A) 1:12
B) 2:12
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C) 4:12
D) 6:12
Answer: C – Standard asphalt shingle application requires a minimum 4:12 slope to properly shed water.
6. A contractor is installing a new TPO roof on a low-slope commercial building. Which method is most
commonly used to secure the TPO membrane seams?
A) Solvent welding
B) Hot air welding (heat welding)
C) Adhesive bonding with contact cement
D) Mechanical fastening with batten bars
Answer: B – TPO seams are welded using hot air welding equipment, which fuses the overlapping edges
into a continuous waterproof membrane.
7. What is the purpose of the aggregate surfacing (gravel or slag) on a built-up roofing (BUR) system?
A) To provide structural reinforcement to the plies
B) To improve the R-value of the insulation
C) To protect the bitumen from ultraviolet (UV) degradation
D) To facilitate faster water drainage
