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

How far must joints in adjacent courses of wood shakes be offset from one another?

• a.At least 3/8 inch
• b.At least 6 inches
• c.At least 1-1/2 inches✓
• d.At least 3 inches

Wood shakes are laid with a side lap of not less than 1-1/2 inches between joints in adjacent courses. 3/8 inch is part of the spacing range, and 3 and 6 inches exceed the code minimum.2025 CRC R905.8.7

What makes up the starter course along the eaves when shakes are the roof covering?

• a.A single course of full-length 24-inch shakes laid flush
• b.Tripled, with felt strips laid between each of the three layers
• c.A single course, set flush with the fascia board edge
• d.Doubled, bottom layer of 15-, 18- or 24-inch shakes or shingles✓

The starter course at the eaves is doubled, and its bottom layer is 15-, 18- or 24-inch wood shakes or shingles. A single course, or a tripled one, is not what the section describes.2025 CRC R905.8.8

Which coating designation does the CRC table list for 55-percent aluminum-zinc-alloy-coated steel roof panels?

• a.ASTM A653 G90
• b.ASTM B370
• c.ASTM B209
• d.ASTM A792 AZ 50✓

The table lists 55 percent aluminum-zinc-alloy-coated steel under ASTM A792 AZ 50. A653 G90 is the zinc-coated galvanized designation, B209 is aluminum, and B370 is copper.2025 CRC Table R905.10.3(2)

Structural standing seam metal panel roof systems must be tested for wind resistance under which standards?

• a.UL 2703 or UL 7103
• b.ASTM E1592 or FM 4474✓
• c.ASTM D3161 or D7158
• d.ASTM C1492 or C1167

Structural standing seam systems are tested to ASTM E1592 or FM 4474. D3161 and D7158 are shingle tests, C1492 and C1167 are tile standards, and UL 2703 and UL 7103 are photovoltaic standards.2025 CRC R905.10.5

Why does the NPS say mastic or sealant is not a viable repair for damaged slates?

• a.It adds too much weight to the roof structure overall
• b.It stains the slate surface permanently within a year
• c.It eventually hardens and cracks, letting water in✓
• d.It cannot be applied below 60 degrees in cool weather

The NPS says mastic and sealants are effective at first but will eventually harden and crack, allowing water to enter. Staining, weight and temperature are not the reasons it gives.NPS Preservation Brief 29

According to the NPS, when are repairs to a slate roof usually less economical than replacing the roof?

• a.When the ridge needs to be repointed with mortar
• b.When 20 percent or more of the slates are failed✓
• c.When a single slate on the roof is cracked
• d.When the roof has been in service over 30 years

If 20 percent or more of the slates on a roof or slope are broken, cracked, missing or sliding, replacement is usually less expensive than individual repairs. One cracked slate, age alone or ridge work does not meet that threshold.NPS Preservation Brief 29

How does the NPS say a damaged slate is first removed?

• a.Pry it up with a long flat pry bar
• b.Burn out its nails with a propane torch
• c.Break it out in pieces with a hammer
• d.Cut or pull its nails with a ripper✓

The damaged slate is removed by cutting or pulling out its nails with a ripper. Prying and hammering break the neighboring slates, and a torch can damage the underlayment and structure.NPS Preservation Brief 29

How does the NPS say a replacement slate is secured?

• a.A wooden wedge driven under, covered by a loose shingle
• b.One nail in the joint above, hidden by a copper strip✓
• c.Adhesive on the back, then covered by a bead of sealant
• d.Two nails at the top corners, covered over by mastic

The new slate is held by one nail through the vertical joint in the course above, and a copper piece with friction fit is slid up over the nail. Two face nails, adhesive and wedges are not the method described.NPS Preservation Brief 29

Storm damage has opened part of a slate roof. What does the NPS advise doing right away?

• a.Paint the exposed area with sealant
• b.Install a temporary covering immediately✓
• c.Wait for dry weather and then inspect
• d.Remove the slates on the slope

The NPS says a temporary roof covering should be installed immediately after the storm to prevent more water damage to the interior. Waiting, sealing and stripping the slope either allow damage or create more.NPS Preservation Brief 29

How tightly should slate nails be driven, according to the NPS?

• a.Not tight, unlike asphalt and wood shingles✓
• b.Tight, driven flush with the slate surface
• c.Hard, until the head bites into the slate
• d.Slightly proud, with the head above the slate

Slate nails should not be driven tight, as is the case with asphalt and wood shingles. Nails driven too far crack the slate, and projecting nails puncture the slate above.NPS Preservation Brief 29

How can a roofer move across a tile roof to fix broken tiles without more damage, per the NPS?

• a.Walk along the ridge tiles of the roof
• b.Walk along the eave line, tile to tile
• c.Spread weight with plywood, planks or sandbags✓
• d.Wear hard-soled boots and step lightly and quickly

The NPS says plywood sheets, planks or burlap bags filled with sand distribute weight so the roofer can move without additional breakage. Ridge, boots and eave paths still concentrate load on the tile.NPS Preservation Brief 30

How does the NPS describe securing a replacement clay tile after the broken one is removed?

• a.Two nails through the face of the new tile
• b.Mastic spread under the new tile and edges
• c.A stainless wire tie to the batten above it
• d.A copper tab nailed below, bent up over the tile✓

A tab of double-thickness copper stripping is nailed to the sheathing below, the new tile is slipped in, and the strip is bent up over the tile. Face nails would crack it, and mastic and wire ties are not what the NPS describes.NPS Preservation Brief 30

What causes galvanic corrosion on a roof, according to the NPS?

• a.Oil residue on new metal
• b.Overdriven nails in asphalt shingles
• c.Standing water on bare wood
• d.Dissimilar metals in direct contact✓

The NPS says galvanic action occurs when dissimilar metals, such as copper and iron, are in direct contact, for example steel nails in copper sheet. The other causes are not galvanic.NPS Preservation Brief 4

How does the NPS say galvanic corrosion can sometimes be prevented between dissimilar roofing metals?

• a.Wrap them in building paper
• b.Press them tightly together
• c.Insert a plastic insulator between them✓
• d.Paint both metals with aluminum paint

In some cases the corrosion is prevented by inserting a plastic insulator between the dissimilar materials. Paint, tight contact and paper do not isolate the metals reliably.NPS Preservation Brief 4

A contractor suggests coating existing asphalt shingles to make them cool. What does the DOE note?

• a.It adds a Class A fire rating to the shingles
• b.It may void the manufacturer's warranty✓
• c.It is required for roofs in hot climate zones
• d.It is a standard field step on most shingle roofs

The DOE says asphalt shingles are not typically coated in the field and doing so may void the manufacturer's warranty. It is not a standard step, it does not add a fire rating, and it is not required.DOE Guidelines for Selecting Cool Roofs

A new covering over wood shingles or shakes creates a combustible concealed space. What must cover the old surface?

• a.Two layers of roofing felt, nailed down securely
• b.Nothing, if the concealed space is vented to the outside air
• c.Gypsum board, mineral or glass fiber, or other accepted material✓
• d.Plywood sheathing nailed over the old shakes

The entire existing surface must be covered with gypsum board, mineral fiber, glass fiber or other accepted materials securely fastened in place. Felt and plywood are combustible, and venting does not remove the requirement.2025 CRC R908.4.1

For which existing roof covering does the CRC bar installing a recover roof?

• a.Slate, clay or cement tile✓
• b.One layer of asphalt shingles
• c.A standing-seam metal roof
• d.A built-up roof in good condition

A recover is not permitted where the existing covering is slate, clay or cement tile (or asbestos-cement tile). A single shingle layer, a standing-seam roof and a sound built-up roof are not listed as barring a recover.2025 CRC R908.4

A hazard is found that cannot be fixed at once without endangering workers or property. Who may stay in the area under the IIPP rule?

• a.Everyone, if a safety monitor is posted nearby
• b.Those needed to correct the condition✓
• c.Workers, as long as a harness is worn
• d.The crew foreman and the lead roofer

When an imminent hazard cannot be immediately abated without endangering employees or property, all exposed personnel are removed except those necessary to correct the condition. A harness, a foreman alone or a monitor does not substitute for removal.Cal. Code Regs. tit. 8 §3203(a)(6)

What must a roofer be given when first employed, under the Construction Safety Orders?

• a.A written test on the California Building Code chapters
• b.A map of the route to the nearest hospital or clinic
• c.Hazard instructions and the Code of Safe Practices to read✓
• d.A copy of the contractor's license and bond card on file

New workers are instructed on the hazards and safety precautions of the work and directed to read the Code of Safe Practices. A license copy, a code test and a hospital map are not what the section requires.Cal. Code Regs. tit. 8 §1510(a)

Who may the employer permit to operate equipment and machinery on a construction job?

• a.Qualified persons✓
• b.Workers over 18
• c.Workers with a driver's license
• d.Anyone the foreman points to

The employer may permit only qualified persons to operate equipment and machinery. Age, a foreman's say-so or a driver's license does not establish qualification.Cal. Code Regs. tit. 8 §1510(b)

What must the employer ensure about first aid on a construction project?

• a.A suitable number of trained persons is available✓
• b.A doctor is present on site during working hours
• c.Workers hold a nursing or first aid certificate
• d.First aid is learned on the job without training

Each employer must ensure the availability of a suitable number of appropriately trained persons to render first aid. It does not require a certificate for every worker or a doctor on site, and untrained first aid does not meet the rule.Cal. Code Regs. tit. 8 §1512

How much drinking water per employee per hour must be provided at the start of the shift under the heat illness standard?

• a.One gallon
• b.One pint
• c.One quart✓
• d.Half a quart

Water must be available at the start of the shift in enough quantity for one quart per employee per hour for the whole shift. A pint or half a quart is too little, and a gallon is more than the standard requires.Cal. Code Regs. tit. 8 §3395

What does the heat illness standard mean by a heat wave?

• a.A day forecast at least 5°F above the monthly average high
• b.A day forecast to be 95°F or higher by afternoon
• c.A day forecast at 80°F or more, 10°F over the five-day average✓
• d.Three or more days in a row forecast above 85°F

A heat wave is a day with a predicted high of at least 80 degrees and at least 10 degrees above the average high of the preceding five days. 95 degrees is the high-heat procedure trigger, and the other options are not in the definition.Cal. Code Regs. tit. 8 §3395(g)

How long must a worker newly assigned to a high heat area be closely observed by a supervisor?

• a.The first 2 days
• b.The first 30 days
• c.The first 14 days✓
• d.The first shift

An employee newly assigned to a high heat area is closely observed for the first 14 days of employment. Two days or one shift is too short for acclimatization, and 30 days exceeds the standard.Cal. Code Regs. tit. 8 §3395(g)

Which item is a required element of a written IIPP under Section 3203?

• a.A fixed price list for each item of safety equipment
• b.A procedure to investigate occupational injury or illness✓
• c.A written list of the tools owned by the contractor
• d.A weekly drug testing schedule for the crew members

The Program must include a procedure to investigate occupational injury or occupational illness. Drug testing, tool inventories and safety item pricing are not Program elements in the section.Cal. Code Regs. tit. 8 §3203(a)(5)

How must personal protective equipment be selected under the Construction Safety Orders?

• a.To fit each affected employee properly✓
• b.To be one standard size for the crew
• c.To match the contractor's colors
• d.To be the cheapest rated model

PPE must be selected so that it properly fits each affected employee. A single size, lowest cost or color matching does not ensure protection.Cal. Code Regs. tit. 8 §1514(f)

What is the 8-hour time-weighted average permissible exposure limit for respirable crystalline silica in construction?

• a.500 micrograms per cubic meter
• b.25 micrograms per cubic meter
• c.5 micrograms per cubic meter
• d.50 micrograms per cubic meter✓

No employee may be exposed to more than 50 micrograms per cubic meter as an 8-hour TWA. 25 is the level below which the section does not apply, and 5 and 500 are not the limit.Cal. Code Regs. tit. 8 §1532.3

Powered cutting of roofing tile is done on a rooftop. Does Section 1530.1 require a dust reduction system?

• a.No; the section covers wood cutting tools alone
• b.No; this work is excepted on rooftops✓
• c.Yes; if the cutting is of roofing pavers
• d.Yes; the rule reaches rooftops and other trades alike

Section 1530.1 says a dust reduction system is not required for rooftop operations with roofing tile, roofing pavers or similar materials. The section covers concrete and masonry cutting generally, so it is not limited to wood, and it does not make rooftop tile work a required case at every location.Cal. Code Regs. tit. 8 §1530.1

The attendant for a kettle must stay within 100 feet while the burner is on. What removes the distance and route limits?

• a.A tightly closed kettle lid with a latch
• b.A second extinguisher placed on the roof edge
• c.An operating thermostat, with service arranged✓
• d.A second fire watch posted on the ground below

If the kettle or tanker is controlled by an operating thermostat and arrangements are made for needed service, the 100-foot and route limits do not apply. A ground fire watch, another extinguisher or a closed lid does not replace attendance.Cal. Code Regs. tit. 8 §1725(d)

What must be maintained between the kettle and the hoist or hand line?

• a.A plywood walkway with cleats
• b.A clear path free of debris✓
• c.A caution line at 6 feet
• d.A second operator at each end

A clear path, free of debris, is kept between the kettle and the hoist or hand line so hot asphalt can be moved without tripping. A caution line, a cleated walkway or two operators is not what the rule specifies.Cal. Code Regs. tit. 8 §1725(e)

A roofer carries hot asphalt on a 6:12 roof. How many buckets may be carried at one time?

• a.One bucket✓
• b.Several, if lids are on
• c.Two buckets
• d.Three buckets

On a roof with a slope of 6:12 or steeper, a worker carries not more than one bucket of hot asphalt or pitch at a time. Two or three buckets, or lids, do not change the limit.Cal. Code Regs. tit. 8 §1725(b)

A mop bucket for hot asphalt can hold no more than how much?

• a.6 gallons
• b.12 gallons
• c.5 gallons
• d.9-1/2 gallons✓

Mop buckets may not exceed 9-1/2 gallons, and they may not be used as carrying buckets. 6 gallons is the carrying bucket limit, and 5 and 12 gallons are not limits in the section.Cal. Code Regs. tit. 8 §1729(a)

A kettle holds 120 gallons. What minimum extinguisher rating must be kept near it while in use?

• a.16:B.C.
• b.2:A extinguisher
• c.20:B.C.
• d.8:B.C.✓

The table sets 8:B.C. for kettles under 150 gallons, 16:B.C. for 150 to 350 gallons, and 20:B.C. above 350 gallons. The larger ratings belong to larger kettles, and a 2:A unit has no flammable-liquid rating.Cal. Code Regs. tit. 8 §1726(d)

More than 5 gallons of flammable liquid is being used on a job site. What must be within 50 feet?

• a.A water barrel and pail
• b.An extinguisher rated at least 2A
• c.An extinguisher rated at least 10B✓
• d.A 5-pound sand bucket

An extinguisher rated not less than 10B must be within 50 feet wherever more than 5 gallons of flammable or combustible liquid are used. A 2A unit is for ordinary combustibles, and a water barrel or sand bucket is not the rated unit required.Cal. Code Regs. tit. 8 §1922

A worker will operate near energized overhead lines carrying 12,000 volts. What minimum clearance does the General Clearances table give?

• a.6 feet✓
• b.10 feet
• c.15 feet
• d.3 feet

For lines from 600 to 50,000 volts the table requires 6 feet. 10 feet applies to lines over 50,000 up to 345,000 volts, and 3 feet and 15 feet are not table values for this range.Cal. Code Regs. tit. 8 §2946

A cover is placed over a roof opening. What load must it safely support?

• a.A fixed 100 pounds per square foot of cover
• b.The greater of 400 lb or twice the imposed weight✓
• c.The weight of a single worker plus tools
• d.The weight of the cover itself and its sign

Covers must support the greater of 400 pounds or twice the weight of employees, equipment and materials imposed on any one square foot of the cover. One worker, a flat 100 pounds per square foot or the cover's own weight does not match that measure.Cal. Code Regs. tit. 8 §1632(b)

By how much must the side rails of a ladder extend above the upper landing it serves?

• a.At least 24 inches
• b.At least 12 inches
• c.At least 6 feet
• d.At least 36 inches✓

Side rails must extend not less than 36 inches above the landing so the climber can step off and hold on. 12 and 24 inches are too short, and 6 feet is more than the rule requires.Cal. Code Regs. tit. 8 §3276

Two short ladders are available, and a crew wants a longer one. What does the ladder rule say about joining them?

• a.They may be joined for roof access work
• b.They may be lashed with rope if the joint is padded
• c.They may be joined if overlapped at least 3 feet
• d.They may not be tied together unless designed for it✓

Ladders shall not be tied or fastened together to provide longer sections unless they are designed for such use and fitted with the necessary hardware. Rope lashing, an overlap or roof-only use does not make the joint safe.Cal. Code Regs. tit. 8 §3276

A crew reroofs a house at 5:12. At what fall distance must roofers be protected under Section 1731?

• a.20 feet or more
• b.15 feet or more
• c.25 feet or more
• d.6 feet or more✓

For slopes from 0:12 through 7:12, protection is required where the fall distance is 6 feet or more. 15 feet is not the trigger in this section, 20 feet is the Section 1730 height for commercial roofing, and 25 feet is the elevation in Section 1671 for safety nets.Cal. Code Regs. tit. 8 §1731(c)(1)

Which work is NOT roofing work under Section 1731?

• a.Installing integral sheet metal
• b.Constructing the roof deck✓
• c.Loading roofing materials
• d.Installing vapor barrier

Roofing work includes loading and installing roofing materials, related insulation, integral sheet metal and vapor barrier work, but not construction of the roof deck. The other three are listed as roofing work.Cal. Code Regs. tit. 8 §1731(b)

A safety monitor is assigned during roof work under a fall protection plan. What restriction applies to the monitor?

• a.No other duties that could draw attention from monitoring✓
• b.Must also carry materials up to the crew on the roof
• c.Must also tend the kettle while watching the crew
• d.Must also operate the hoist during roof loading

The safety monitor shall not have other responsibilities that could take attention from monitoring, and must stay in sight and communication with the employee. Hoisting, running a kettle or carrying materials are exactly the distractions barred.Cal. Code Regs. tit. 8 §1671.2

A roof warning line is rigged with rope. Section 1730 sets what minimum tensile strength for it?

• a.5,000 pounds
• b.200 pounds
• c.500 pounds✓
• d.1,000 pounds

Warning lines must have a minimum tensile strength of 500 pounds. 200 pounds is the breaking strength for a control line in Section 1671.2, and 1,000 and 5,000 pounds are not warning line values (5,000 pounds applies to lanyards).Cal. Code Regs. tit. 8 §1730(b)(2)

What do the headers used with roof warning lines consist of?

• a.Ropes and flags strung between ladders at each edge
• b.Painted lines on the roof deck at 6-foot intervals
• c.Plywood panels nailed across the ridge and the hips
• d.Roofing sheets or materials laid parallel to the edge✓

Headers are sheets of roofing or other roofing materials laid parallel to the roof edges to warn employees they are nearing the edge. Ropes between ladders, ridge plywood and painted lines are not the headers described.Cal. Code Regs. tit. 8 §1730(b)(3)

Equipment pulled by an operator walking backwards is limited on which roofs under Section 1730?

• a.It may not be used on slopes greater than 4:12✓
• b.It may be used on steep slopes with a safety monitor
• c.It may not be used on roofs that have parapets
• d.It may not be used on slopes below 2:12

Equipment pulled by an operator walking backwards shall not be used on a roof with a slope greater than 4:12. Flatter roofs are not barred, parapets are not the trigger, and the rule does restrict slope.Cal. Code Regs. tit. 8 §1730(d)

What minimum breaking strength must lanyards and vertical lifelines in a personal fall arrest system have?

• a.3,000 pounds
• b.1,800 pounds
• c.5,000 pounds✓
• d.500 pounds

Lanyards and vertical lifelines must have a minimum breaking strength of 5,000 pounds. 1,800 pounds is the maximum arresting force on a harness, 3,000 pounds applies to self-retracting lifelines, and 500 pounds is a warning-line strength.Cal. Code Regs. tit. 8 §1670(b)

A personal fall arrest system is used with a body harness. How far may the worker free fall?

• a.No more than 6 feet✓
• b.No more than 10 feet
• c.No more than 2 feet
• d.No more than 3.5 feet

The system must be rigged so the employee can neither free fall more than 6 feet nor contact a lower level. 2 feet is the positioning device limit, 3.5 feet is the maximum deceleration distance, and 10 feet exceeds the rule.Cal. Code Regs. tit. 8 §1670(b)(11)

Where must the attachment point of a body harness be located?

• a.At the front of the waist, on a belt D-ring
• b.At a side D-ring located on either hip
• c.Center of back, at or above shoulder level✓
• d.At the ankle level on a sewn leg strap

The attachment point is in the center of the wearer's back near shoulder level or above the head. Waist, hip or ankle attachment would pull the wearer into a bent or inverted position in a fall.Cal. Code Regs. tit. 8 §1670(b)(12)

Where must a control line be erected relative to the leading or unprotected edge?

• a.At least 30 feet from it
• b.Between 6 and 25 feet from it✓
• c.Between 2 and 5 feet from it
• d.At the edge

Control lines are erected not less than 6 feet nor more than 25 feet from the unprotected or leading edge. A line within 5 feet is too close to be a barrier, 30 feet is beyond the limit, and a line at the edge does not mark a zone.Cal. Code Regs. tit. 8 §1671.2

A ramp is used only to load roofing materials at an elevation up to 20 feet. What is its minimum width?

• a.24 inches
• b.20 inches
• c.40 inches✓
• d.60 inches

Ramps or runways used exclusively for loading roofing materials up to 20 feet high must be at least 40 inches wide. 20 and 24 inches are too narrow, and 60 inches exceeds the rule.Cal. Code Regs. tit. 8 §1724(h)

On a roofer's crawling board, cleats may be set no farther apart than what?

• a.12 inches
• b.36 inches
• c.24 inches✓
• d.48 inches

Crawling boards have cleats of at least 1 by 1-1/2 inch material spaced at equal intervals not exceeding 24 inches. 12 inches is closer than needed, and 36 and 48 inches are wider than the limit.Cal. Code Regs. tit. 8 §1724(b)