CSLB C-39 Roofing (Trade Exam) — All Questions

Which material is named in CSLB's definition of the C-39 Roofing classification?

• a.Structural steel
• b.Urethane foam✓
• c.Gypsum drywall
• d.Ceramic floor tile

CSLB's C-39 definition lists roofing materials including urethane foam, metal roofing systems, shakes, shingles, tile and slate. Structural steel, drywall and floor tile belong to other classifications.Cal. Code Regs. tit. 16 §832.39 (C-39 classification)

What is the minimum slope for building-integrated photovoltaic (BIPV) roof panels applied directly to the roof deck?

• a.1/4:12
• b.1:12
• c.4:12
• d.2:12✓

The CRC allows BIPV roof panels only on slopes of 2 units vertical in 12 horizontal or greater. One-quarter inch per foot is the minimum for membrane systems, not BIPV.2025 CRC R905.16.2

A homeowner wants a new covering on a 3:12 roof. Which covering is NOT permitted at that slope?

• a.Metal roof shingles
• b.Wood shakes
• c.Slate shingles✓
• d.Asphalt shingles

Slate requires a slope of 4:12 or greater. Wood shakes and metal shingles are allowed from 3:12, and asphalt shingles from 2:12.2025 CRC R905.6.2

Clay tile is proposed for a porch roof with a 2:12 slope. Is it allowed?

• a.Yes, with double underlayment
• b.Yes, if the tile is fastened every row
• c.No; tile needs 2-1/2:12✓
• d.Yes, if the tile is under 9 psf

Clay and concrete tile may be installed only on slopes of 2-1/2:12 or greater. Double underlayment is required from 2-1/2:12 to 4:12, but it cannot make a 2:12 tile roof legal.2025 CRC R905.3.2

Outside fire hazard severity zones, when must the ENTIRE existing roof covering be brought to at least Class C?

• a.When more than 50 percent is replaced within one year✓
• b.When more than 25 percent is replaced within five years
• c.Only when the building is sold
• d.Whenever any repair is made

The CRC requires the entire roof covering to be at least Class C when more than 50 percent of the total roof area is replaced within any one-year period. Any covering applied in a repair must itself be at least Class C.2025 CRC R902.1.2

Which roof assembly does the CBC treat as Class A without a listing?

• a.Untreated wood shakes
• b.Asphalt shingles on plywood
• c.A single-ply membrane on insulation
• d.An exposed concrete roof deck✓

The CBC's Class A exceptions include roof assemblies with coverings of brick, masonry or an exposed concrete roof deck. Shingles, shakes and membranes need a listing to establish their class.2025 CBC 1505.2

In the wildland-urban interface, how are roof assemblies with fire-retardant-treated wood shingles and shakes classified?

• a.As Class A assemblies✓
• b.As nonclassified roofing
• c.As Class B assemblies
• d.As Class C assemblies

The WUI Code requires roof assemblies containing fire-retardant-treated wood shingles and shakes to comply with CBC 1505.6 and be classified as Class A assemblies.2025 CWUIC 503.2.3

A house in Climate Zone 6 is getting a complete new low-sloped roof. What aged solar reflectance must the new roofing product have, if no trade-off is used?

• a.At least 0.10
• b.At least 0.63✓
• c.No requirement in Climate Zone 6
• d.At least 0.20

Low-sloped residential reroofs in Climate Zones 4 and 6 through 15 need an aged solar reflectance of at least 0.63 and thermal emittance of at least 0.75, or SRI 75. The 0.20 value is for steep-sloped roofs.2025 Energy Code 150.2(b)1I

For a steep-slope residential reroof in Climate Zone 9, which is listed as an alternative that counts as equivalent to the cool-roof product requirement?

• a.A thicker felt underlayment
• b.A new ridge vent line
• c.A radiant barrier in the attic✓
• d.A darker shingle color

The Energy Code treats a radiant barrier in the attic (not installed directly above spaced sheathing), R-38 ceiling insulation, no attic ducts in listed zones, or R-2 continuous deck insulation as equivalent to the steep-slope reflectance requirement.2025 Energy Code 150.2(b)1I

A nonresidential building has a 2,400 sq ft roof. The owner will replace 1,500 sq ft. Do the Energy Code roof-alteration requirements apply?

• a.Only if it is a hotel or motel
• b.Yes; over half is altered✓
• c.No; only full replacements count
• d.No; under 2,000 sq ft is altered

The trigger is more than 50 percent of the roof or more than 2,000 sq ft, whichever is less. Half of 2,400 sq ft is 1,200 sq ft, which is the lesser figure, and 1,500 sq ft exceeds it.2025 Energy Code 141.0(b)2B

Under the Energy Code, how is a roof with a slope of 1-1/2:12 classified?

• a.Steep-sloped
• b.Low-sloped✓
• c.Flat roof exempt from rules
• d.Mansard

The Energy Code defines a low-sloped roof as one with a rise-to-run ratio less than 2:12 and a steep-sloped roof as 2:12 or greater.2025 Energy Code 100.1 definitions

Besides C-39 Roofing, which classification does CSLB list as unable to submit a workers' compensation exemption?

• a.C-20 Warm-Air HVAC✓
• b.C-54 Ceramic and Mosaic Tile
• c.C-27 Landscaping
• d.C-33 Painting

CSLB lists C-8 Concrete, C-20 Warm-Air HVAC, C-22 Asbestos Abatement, C-39 Roofing and C-61/D-49 Tree Service as unable to submit an exemption.CSLB Issuing My License

How much credit toward the four-year experience requirement can a Certificate of Completion of Apprenticeship in roofing provide?

• a.Up to four years
• b.Up to one year
• c.None at all
• d.Up to three years✓

CSLB may grant up to three years of credit for an accredited apprenticeship certificate in the classification, but at least one year must be practical experience.CSLB Experience for Exam

A building is 45 x 28 ft in plan including overhangs, with a uniform 5:12 roof. How many squares of roof surface are there before waste?

• a.13.65 squares✓
• b.15.00 squares
• c.12.60 squares
• d.11.70 squares

The plan area is 1,260 sq ft and the 5:12 slope factor is 13/12, or about 1.083, so the roof surface is 1,365 sq ft, or 13.65 squares. 12.60 squares omits the slope factor.Roofing math

A roof covers 1,600 sq ft of plan area at a uniform 9:12 slope. What is its true surface area?

• a.2,262 sq ft
• b.1,923 sq ft
• c.2,000 sq ft✓
• d.1,600 sq ft

At 9:12 the slope factor is the square root of (144 + 81) divided by 12, which is 15/12 = 1.25. 1,600 x 1.25 = 2,000 sq ft.Roofing math

What is a 6:12 roof slope expressed as a percentage?

• a.60 percent
• b.50 percent✓
• c.25 percent
• d.6 percent

Percent slope is rise divided by run: 6 divided by 12 is 0.5, or 50 percent. The CRC writes 3:12 as 25-percent slope by the same arithmetic.2025 CRC slope notation

A roof needs 96 lineal feet of drip edge. Pieces are 10 ft long and every joint takes the code minimum lap. How many pieces are needed?

• a.10 pieces✓
• b.9 pieces
• c.8 pieces
• d.11 pieces

Drip edge segments must overlap at least 2 inches, so each 10-ft piece covers 9 ft 10 in. 96 divided by 9.833 is 9.8, which rounds up to 10 pieces.2025 CRC R905.2.8.5

A roof is 22 squares before waste. With 10 percent waste and shingles packaged 3 bundles per square, how many bundles should be ordered?

• a.66 bundles
• b.70 bundles
• c.76 bundles
• d.73 bundles✓

22 squares plus 10 percent is 24.2 squares; 24.2 x 3 = 72.6 bundles, rounded up to 73. Sixty-six bundles leaves out the waste allowance.Roofing math

An attic is 1,200 sq ft and does not meet the conditions for a reduced ventilation ratio. What minimum net free ventilating area is required?

• a.1,152 sq in✓
• b.2,400 sq in
• c.576 sq in
• d.1,200 sq in

The default ratio is 1/150: 1,200 divided by 150 is 8 sq ft, and 8 x 144 = 1,152 sq in. The 576 sq in figure is the 1/300 ratio, which needs the exception's conditions.2025 CRC R806.2

A rectangular hip roof with equal slopes on all sides measures 30 x 50 ft including overhangs. How long is the ridge?

• a.30 ft
• b.50 ft
• c.20 ft✓
• d.25 ft

For an equal-slope rectangular hip roof, the ridge is the length minus the width: 50 - 30 = 20 ft. A gable roof's ridge would run the full 50 ft.Roofing math

A four-person crew installs 10 squares per 8-hour day. How many labor hours does a 35-square job take?

• a.28 hours
• b.112 hours✓
• c.140 hours
• d.80 hours

The job takes 35 / 10 = 3.5 days, and 4 workers x 8 hours x 3.5 days = 112 labor hours. Twenty-eight hours counts days but not workers.Roofing math

A job's cost is $14,000. What selling price gives a 30 percent margin on price?

• a.$19,600
• b.$18,200
• c.$16,800
• d.$20,000✓

For a 30 percent margin, cost is 70 percent of price: $14,000 / 0.70 = $20,000. Adding 30 percent to cost ($18,200) is a markup that yields only about a 23 percent margin.Roofing math