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

Under the Fire Code, where must the attendant of an operating asphalt kettle be?

• a.Within 100 feet, in sight✓
• b.Anywhere on the roof above it
• c.Inside the truck cab
• d.Within 500 feet by radio

An operating kettle must be attended by at least one knowledgeable employee within 100 feet who has the kettle within sight, with no ladder in the route.2025 CFC 303.4

What is the maximum capacity of a hi-boy used to carry hot asphalt on a roof?

• a.100 gallons
• b.55 gallons✓
• c.20 gallons
• d.9-1/2 gallons

The Fire Code limits hi-boys to 55 gallons, requires noncombustible construction, and allows no heat source as part of a hi-boy.2025 CFC 303.7

A crew wants to tow a kettle to the next job with the burner running to save heating time. What does the Fire Code say?

• a.Allowed if the lid is closed
• b.Not allowed on any road✓
• c.Allowed with a flag car
• d.Allowed below 25 mph

Asphalt kettles may not be transported over any highway, road or street while the heat source is operating, except kettles patching road surfaces.2025 CFC 303.1

Asbestos-containing roofing is being removed next to rooftop air handlers. What must be done with the air intakes?

• a.Isolate them or shut the system down✓
• b.Nothing if the crew wears respirators
• c.Point a fan at them
• d.Tape a sign on each unit

During removal of asbestos-containing roofing, roof-level heating and ventilation air intake sources must be isolated or the ventilation system shut down.Cal. Code Regs. tit. 8 §1529

Two crews each remove 15 square feet of intact asbestos-containing roofing on the same roof on the same day. Does the under-25-square-foot allowance apply?

• a.Yes, if the crews use different tools
• b.Yes, if the work is on different slopes
• c.No; count all same-day work✓
• d.Yes; each crew is under 25 sq ft

In deciding whether a job is under 25 square feet, the employer must count all removal and repair work performed on the same roof on the same day. Together the crews remove 30 square feet.Cal. Code Regs. tit. 8 §1529

An existing roof covering is water soaked and no longer an adequate base. The owner asks for a recover. What does the code say?

• a.A recover is allowed after one week of drying
• b.A recover is allowed with a new base sheet
• c.A recover is allowed if the new roof is metal
• d.A recover is not permitted✓

A roof recover is not permitted where the existing roof or roof covering is water soaked or deteriorated to the point it is not an adequate base for additional roofing.2025 CRC R908.4

Which new system may be installed over an existing roof covering without removing it, because it carries its own loads to the structure?

• a.Shingles over two existing layers
• b.Clay tile over existing slate
• c.A separate standing-seam system✓
• d.Wood shakes over existing clay tile

Complete and separate roofing systems, such as standing-seam metal systems that transmit loads directly to the structure and do not rely on the existing roof, do not require removal of existing coverings.2025 CRC R908.4

What does the CRC mean by a roof replacement?

• a.Replacing only damaged shingles
• b.Coating the existing roof surface
• c.Removal down to the deck✓
• d.Adding a new layer over the old one

Roof replacement includes the removal of existing layers of roof coverings down to the roof deck. Installing a new covering over the old one is a recover.2025 CRC R908.3

An existing ice barrier membrane is well adhered to a sound, dry deck. During replacement, what may the roofer do with it?

• a.Cover it with more ice barrier, if permitted✓
• b.Leave it exposed as the finished roof
• c.Cover it with wood shakes directly
• d.Always grind it off the deck

Where an adhered ice barrier is on sheathing that is not water soaked or deteriorated, it may remain and be covered with an additional ice barrier layer where the roof covering and ice barrier manufacturers permit.2025 CRC R908.3 exception

During a ballasted single-ply reroof, some of the existing ballast stones are cracked. What may be done with them?

• a.Reinstall them at the roof corners
• b.Reinstall them under the new membrane
• c.Reinstall them if painted
• d.They may not be reinstalled✓

Existing ballast that is damaged, cracked or broken shall not be reinstalled under the CBC's reroofing section.2025 CBC 1512.4

A walkway is provided past a roofing job for pedestrians. What is its minimum width?

• a.2 feet
• b.4 feet✓
• c.6 feet
• d.3 feet

Walkways must be of sufficient width for the pedestrian traffic but not less than 4 feet wide, with a durable walking surface.2025 CBC 3306.2

Where may pallets of roof tile be staged next to a neighbor's property line?

• a.Where no one or nothing is endangered✓
• b.Anywhere on the owner's lot
• c.In the neighbor's driveway overnight
• d.Against the neighbor's fence to save space

Construction equipment and materials must be stored and placed so as not to endanger the public, the workers or adjoining property for the duration of the project.2025 CBC 3301.2

When may an overhead conductor near a roofing job be treated as de-energized?

• a.When it sags below the roof edge
• b.When it looks old and unused
• c.When the homeowner says it is off
• d.After owner verification and visible grounding✓

Any overhead conductor is considered energized unless and until the person owning or operating the line verifies it is not energized and the line is visibly grounded at the work site.Cal. Code Regs. tit. 8 §2946(d)

What minimum design slope does the CRC require for a modified bitumen roof, for drainage?

• a.1/8 inch per foot
• b.1/4 inch per foot✓
• c.1 inch per foot
• d.1/2 inch per foot

Modified bitumen roofing needs a design slope of at least one-fourth unit vertical in 12 horizontal (2 percent) for drainage. One-eighth is allowed only for coal-tar built-up roofs.2025 CRC R905.11.1

Which standards may spray-applied polyurethane foam roofing insulation meet under the CRC?

• a.ASTM C1029 or D7425✓
• b.ASTM D3462 or D7158
• c.ASTM D226 or D4869
• d.ASTM C1167 or C1492

SPF roofing foam must comply with ASTM C1029 Type III or IV or ASTM D7425. D226 is felt underlayment, D3462 asphalt shingles and C1167 clay tile.2025 CRC R905.13.2

A foam crew finishes spraying at 9:00 a.m. What is the EARLIEST the protective coating may be applied?

• a.11:00 a.m.✓
• b.The next morning
• c.After 72 hours
• d.9:30 a.m.

The coating must be applied not less than 2 hours nor more than 72 hours after the foam. Two hours after 9:00 a.m. is 11:00 a.m.; 72 hours is the latest limit, not the earliest.2025 CRC R905.13.3

Which set of standards does the CBC list for liquid-applied roofing?

• a.ASTM C836, C957 or D3468✓
• b.ASTM C406, C1167 or C1492
• c.ASTM D4637, D6878 or D4434
• d.ASTM D226, D4869 or D1970

Liquid-applied roofing must comply with ASTM C836, ASTM C957 or ASTM D3468. D4637 and D6878 are single-ply standards; D226 and D4869 are felts.2025 CBC 1507.14.2

Which ASTM standard does the CBC list for EPDM single-ply membrane?

• a.ASTM D4434
• b.ASTM D5019
• c.ASTM D6878
• d.ASTM D4637✓

The single-ply table lists EPDM under ASTM D4637, PVC under D4434, TPO under D6878, and CSPE or PIB under D5019.2025 CBC Table 1507.12.2