CSLB C-21 Building Moving and Demolition (Trade Exam) — All Questions

A floor safe for 90 pounds per square foot carries 22,500 pounds of debris on 300 square feet. Is it within the limit?

• a.No, because the load is 300 pounds per square foot
• b.No, because the load is 120 pounds per square foot
• c.Yes, because the load is 7,500 pounds per square foot
• d.Yes, because the load is 75 pounds per square foot✓

22,500 ÷ 300 = 75 pounds per square foot, which is less than 90. One hundred twenty has no basis in the data. Seventy-five hundred multiplies instead of divides. Three hundred is the area.Cal. Code Regs., tit. 8, §1735(e)

A steep chute has loading openings at each floor. What are the limits on those openings?

• a.Open openings as tall as the crew needs, so that debris can pass freely at the floors
• b.Closable openings no more than 48 inches high, kept closed on lower floors when not in use✓
• c.Permanently closed openings on the floors except the top one
• d.Netted openings in place of closures, with no height limit

Steep chutes are enclosed except for openings with closures; openings may not exceed 48 inches measured along the wall, and below the top floor they are kept closed when not in use. The rule requires closures and a height limit. Openings may be used, but they are kept closed when not in use. Netting is not a closure.Cal. Code Regs., tit. 8, §1736(j)

A wall holds back earth behind a neighboring structure. Under the federal rule, when may it be demolished?

• a.After the earth has been braced or the adjoining structure underpinned✓
• b.After the wall has been wet down to control the dust
• c.After the floors above the wall have been removed and cleared
• d.After the neighbor has been notified by letter of the work

Retaining walls shall not be demolished until the earth has been properly braced or adjoining structures underpinned. A letter does not support the earth. Removing floors does not support the earth. Wetting the wall does not support the earth.29 CFR 1926.854(h)

Asbestos waste is generated during stripping. What does the federal rule require during the stripping operation?

• a.The RACM is swept dry into a pile with brooms
• b.The RACM is blown out of the work area with compressed air
• c.The RACM is dried so that it can be bagged more easily
• d.The RACM is adequately wet while it is stripped✓

When RACM is stripped from a component in place, it is adequately wet during the stripping operation. Drying releases fibers. Dry sweeping releases fibers. Compressed air spreads fibers.40 CFR 61.145(c)

Fill deeper than 12 inches will bear a shallow foundation. What governs its placement?

• a.The foreman's judgment of how firm the placed fill feels
• b.A fixed 90 percent figure with no report
• c.The slope of the neighboring lot toward the foundation
• d.The provisions of an approved geotechnical report✓

Where shallow foundations bear on compacted fill, the fill shall comply with an approved geotechnical report; thin fill may use the 90 percent exception. Judgment is not the code's method. The 90 percent exception is for fill 12 inches or less. A neighboring slope does not govern.2025 CBC §1804.6

How is steel construction dismantled under Cal/OSHA's demolition rule?

• a.Column length by column length and tier by tier, without overstressing members✓
• b.By cutting the connections in one tier at once
• c.Columns first, working from the ground up toward the roof
• d.The beams on the floors first, then the columns together

Steel construction shall be dismantled column length by column length, and tier by tier. Removing all beams first leaves columns unbraced. The work proceeds from the top, not the ground up. Cutting a whole tier at once is not the sequence.Cal. Code Regs., tit. 8, §1735(n)

Where must service lines such as gas, water, steam and sewer be controlled before demolition work starts, under the federal rule?

• a.At the roof penetrations
• b.At the meter inside the building
• c.At each fixture inside the building
• d.Outside the building line✓

Service lines shall be shut off, capped or otherwise controlled outside the building line before demolition starts. Control is at the building line and not at each fixture. Roof penetrations are not the control point. Interior meters are not the stated location.29 CFR 1926.850(c)

A job removes 30 mercury thermostats and a pallet of used batteries. How are they classified?

• a.As universal wastes, kept apart from the debris stream✓
• b.As mixed debris, to be hauled in the general bin
• c.As clean metal, to be recycled with structural steel
• d.As asbestos waste, to be removed by a certified contractor

Mercury-containing equipment and batteries are two of the five federal universal waste categories. Mercury equipment and batteries are not clean scrap. Mixing them into general debris contaminates it. They are not asbestos materials.EPA universal waste (40 CFR Part 273)

How must waste materials be removed from a demolition site under the Building Code?

• a.By the shortest route to the disposal site, with no regard to neighbors
• b.By the owner, using the owner's own vehicles
• c.Without injury or damage to persons, adjacent property and public rights-of-way✓
• d.At night, after the site is closed to the public

Waste materials shall be removed in a manner that prevents injury or damage to persons, adjacent properties and public rights-of-way. The rule protects neighbors and the public. The rule sets no night-only condition. The rule does not limit removal to the owner.2025 CBC §3301.5

What is the minimum width of the safe walkways required where workers must reach a point without walking on exposed beams, under the federal manual floor removal rule?

• a.24 inches
• b.36 inches
• c.48 inches
• d.18 inches✓

Safe walkways must be not less than 18 inches wide, formed of planks at least 2 inches thick if wood, or equivalent metal. Twenty-four inches is wider than the rule requires. Thirty-six inches is wider than the rule requires. Forty-eight inches is wider than the rule requires.29 CFR 1926.855(c)

A job generated 100 tons of nonhazardous debris, with 70 tons diverted. The crew then mixes 10 tons of the metal into the general landfill bin. What happens to the diversion share?

• a.It stays at 70 percent, since the metal is still metal
• b.It drops from 70 percent to 60 percent✓
• c.It rises to 80 percent
• d.It drops from 70 percent to 63 percent

Diverted tons fall from 70 to 60 out of 100, so the share falls to 60 percent. Metal sent to landfill is not diverted. The share does not rise. Sixty-three does not match the 10-ton change.CalRecycle on CALGreen

A basement excavation measures 25 feet by 20 feet and is 7 feet deep. How many cubic yards of backfill does it need, before compaction allowances?

• a.1,167 cubic yards
• b.3,500 cubic yards
• c.129.6 cubic yards✓
• d.389 cubic yards

25 × 20 × 7 = 3,500 cubic feet, and 3,500 ÷ 27 = 129.6 cubic yards. Thirty-five hundred is the cubic feet. Three hundred eighty-nine divides by 9. One thousand one hundred sixty-seven divides by 3.CSLB 13E-21 (03-2026), computation questions

A floor can safely carry 100 pounds per square foot. How many pounds of debris may be stored on 500 square feet of it?

• a.Up to 100,000 pounds
• b.Up to 500 pounds
• c.Up to 50,000 pounds✓
• d.Up to 5,000 pounds

100 × 500 = 50,000 pounds is the most the area may carry. Five thousand drops a zero. Five hundred is the area, not the load. One hundred thousand doubles the area.Cal. Code Regs., tit. 8, §1735(e)

The laboratory maximum dry density of a fill is 115 pounds per cubic foot. What is the least in-place dry density for the 90 percent exception?

• a.115 pounds per cubic foot
• b.103.5 pounds per cubic foot✓
• c.126.5 pounds per cubic foot
• d.90 pounds per cubic foot

0.90 × 115 = 103.5 pounds per cubic foot. Ninety is the percentage, not the density. One hundred fifteen is the maximum itself. One hundred twenty-six point five adds 10 percent.2025 CBC §1804.6

A utility trench is 100 feet long, 3 feet wide and 4 feet deep. How many cubic yards of backfill does it take?

• a.1,200 cubic yards
• b.44.4 cubic yards✓
• c.133 cubic yards
• d.400 cubic yards

100 × 3 × 4 = 1,200 cubic feet, and 1,200 ÷ 27 = 44.4 cubic yards. Twelve hundred is the cubic feet. One hundred thirty-three divides by 9. Four hundred divides by 3.CSLB 13E-21 (03-2026), computation questions

An employee needs to cross a floor where only joists remain. What does Cal/OSHA say?

• a.Walking is allowed for employees with more than five years' experience
• b.Walking across exposed floor joists is prohibited, so planks or runways must be used✓
• c.Walking is allowed if the employee wears a hard hat and boots
• d.Walking is allowed if the joists are at least 2 by 10 inches

Walking across exposed floor joists, steel beams or girders is prohibited. PPE does not lift the prohibition. Joist size does not lift it. Experience does not lift it.Cal. Code Regs., tit. 8, §1735(i)

A single-story masonry wall stands 11 feet high with no lateral support. Under the free-standing wall rule, what applies?

• a.It must be braced, because masonry walls need lateral bracing
• b.It must be taken down at once, because no free-standing wall may remain
• c.It must be braced, because free-standing walls need bracing
• d.It is not more than one story or 12 feet, so the bracing rule does not apply, but it must still be left stable at the end of the day✓

The bracing rule applies to a wall more than one story or 12 feet high, and 11 feet in one story is neither. The rule has a height and story test. The rule does not depend on masonry. Taking it down at once is not required.Cal. Code Regs., tit. 8, §1735(m)

What does Cal/OSHA say about material storage areas and walkways on a construction site?

• a.They must be at least 20 feet from a building on the site
• b.They must be paved before material is stored there
• c.They are kept reasonably free of dangerous depressions, obstructions and debris✓
• d.They may hold debris as long as the area is marked with paint

Material storage areas and walkways shall be maintained reasonably free of dangerous depressions, obstructions and debris. Paint does not remove the hazard. The rule does not require paving. The rule sets no 20-foot distance.Cal. Code Regs., tit. 8, §1513(c)

Under the federal rule, floor openings within what distance of a wall being demolished must be planked solid, unless employees are kept out of the area below?

• a.8 feet
• b.10 feet✓
• c.5 feet
• d.2 feet

Floor openings within 10 feet of any wall being demolished shall be planked solid. Two feet is shorter than the rule. Five feet is shorter than the rule. Eight feet is shorter than the rule.29 CFR 1926.854(e)

Why does the crew cut the rebar out of broken concrete before loading it?

• a.To keep the concrete clean for recycling and send the steel to scrap✓
• b.To lower the diversion percentage so the plan is easier to meet
• c.To avoid having to weigh each load that leaves the site
• d.To make the broken concrete count as hazardous waste at the facility

Separating steel from concrete keeps both streams clean and recyclable, which supports the diversion plan. Rebar does not make concrete hazardous. Weighing and documentation still apply. The aim is to raise diversion.CalRecycle on CALGreen

Where must walkways meeting the runway section be provided on a demolition project?

• a.On the floors, throughout the job
• b.Every 20 feet along the runway section
• c.At the ground-level entrances, with no walkways required higher up
• d.Where necessary for access✓

Walkways that meet the runway section shall be provided where necessary for access. The rule sets no spacing; it says where necessary for access. Walkways are provided where necessary, not on every floor automatically. The rule is not limited to entrances.Cal. Code Regs., tit. 8, §1735(h)

A job produces 120 cubic yards of debris, and the truck bodies hold 14 cubic yards each. How many loads are needed?

• a.10 loads
• b.106 loads
• c.8 loads
• d.9 loads✓

120 ÷ 14 = 8.57, and a partial load is still a load, so the count rounds up to 9. Eight loads rounds down and leaves debris behind. Ten loads over-counts. One hundred six subtracts 14 from 120.CSLB 13E-21 (03-2026), computation questions

A job generates 90 tons of nonhazardous debris. Of that, 40 tons of concrete, 10 tons of metal and 10 tons of wood are diverted and 30 tons are landfilled. What share was diverted?

• a.60 percent
• b.33 percent
• c.67 percent✓
• d.75 percent

40 + 10 + 10 = 60 tons, and 60 ÷ 90 = 66.7 percent, about 67 percent. Thirty-three percent is the landfilled share. Sixty is the tonnage, not the percentage. Seventy-five has no basis in the arithmetic.CalRecycle on CALGreen

How thick and how high must the toeboard or bumper be at a chute opening in Title 8?

• a.Six inches thick and twelve inches high
• b.Four inches thick and six inches high
• c.Three inches thick and three inches high
• d.Six inches thick and six inches high✓

Title 8 requires a toeboard or bumper not less than six inches thick and six inches high. Four inches thick is the federal figure. Twelve inches high is more than the rule requires. Three inches is below the minimum.Cal. Code Regs., tit. 8, §1736(i)(1)

Which code governs fire safety during demolition under Chapter 33 of the Building Code?

• a.The Plumbing Code, since hot work involves gas piping
• b.The Electrical Code, since temporary power feeds the equipment
• c.The Building Code and the construction chapter of the Fire Code✓
• d.The Energy Code, since demolition affects the building envelope

Fire safety during demolition shall comply with the applicable requirements of the Building Code and the applicable provisions of Chapter 33 of the Fire Code. The Plumbing Code does not govern demolition fire safety. The Energy Code does not govern demolition fire safety. The Electrical Code alone does not govern it.2025 CBC §3303.7

Fill 5 feet deep is placed in 6-inch compacted lifts. How many lifts are needed?

• a.10 lifts✓
• b.30 lifts
• c.5 lifts
• d.12 lifts

5 feet is 60 inches, and 60 ÷ 6 = 10 lifts. Five lifts treats each foot as a lift. Thirty lifts uses 2-inch lifts. Twelve lifts uses 5-inch lifts.2025 CBC §1804.3

Which soil is acceptable as backfill outside a foundation?

• a.Topsoil full of roots, grass and other plant material
• b.Soil free of organic material, debris, cobbles and boulders✓
• c.Soil mixed with broken concrete and lumber scraps from the job
• d.Soil that contains boulders larger than a fist in places

Backfill shall be free of organic material, construction debris, cobbles and boulders. Broken concrete and lumber are construction debris. Roots and grass are organic material. Boulders and cobbles are prohibited.2025 CBC §1804.3

Where must the gate on a truck-loading chute be installed?

• a.On the truck's tailgate, so the driver can control it
• b.In each chute at or near the discharge end✓
• c.In chutes that are more than 10 feet long
• d.At the top opening of the chute where debris enters

Gates shall be installed in each chute at or near the discharge end. The rule covers each chute used to load trucks. The top opening is where material enters, not where it is controlled. The tailgate is not part of the chute.Cal. Code Regs., tit. 8, §1736(b)

Waste is dropped to a point outside the exterior walls. What must be posted?

• a.A sign giving the tonnage of debris dropped each day
• b.A sign giving the permit number and the permit date
• c.A sign giving the name of the hauler and a phone number
• d.Signs warning of the hazards of falling debris✓

Enclosed chutes or barricades are used, and signs shall be posted to warn employees of falling debris hazards. A hauler's name does not warn of the hazard. Tonnage does not warn of the hazard. A permit number does not warn of the hazard.Cal. Code Regs., tit. 8, §1736(a)

Controlled low-strength material is used as backfill outside a foundation. What does the code say about compacting it?

• a.It need not be compacted✓
• b.It may be used if it is compacted twice
• c.It must be compacted in 6-inch lifts
• d.It must be compacted to 95 percent of maximum density

The backfill rule excepts CLSM: it need not be compacted. Lifts apply to soil backfill, not CLSM. No percentage applies to CLSM in the exception. No double compaction applies.2025 CBC §1804.3

A stairwell is used for access during multi-story demolition. Where must it be covered over?

• a.At the roof, above the work being done by the crew
• b.At a point not less than two floors below the floor where work is being performed✓
• c.At the ground floor, whatever floor is being demolished
• d.On the floor where work is performed, directly under the crew

The stairwell is completely and substantially covered at a point not less than two floors below the working floor. The cover goes below the work, not at it. The cover is two floors below the work, not at the ground in every case. A cover at the roof does not protect the path below.Cal. Code Regs., tit. 8, §1735(q)

A canopy 8 feet deep and 10 feet wide covers an entrance. At 150 pounds per square foot, what total load must it be able to sustain?

• a.1,500 pounds
• b.12,500 pounds
• c.12,000 pounds✓
• d.1,200 pounds

The area is 8 × 10 = 80 square feet, and 80 × 150 = 12,000 pounds. One thousand two hundred drops a zero. One thousand five hundred multiplies 10 by 150 only. Twelve thousand five hundred has no basis in the arithmetic.Cal. Code Regs., tit. 8, §1735(j)

A foreman proposes a shed that extends 6 feet from the building face over an employee entrance. Does it meet the rule?

• a.No, since the shed must extend at least 12 feet
• b.Yes, if the shed is rated for 150 pounds per square foot
• c.No, since the protection must extend at least 8 feet✓
• d.Yes, since 6 feet is enough to clear the doorway

The protection must extend from the face of the building for a minimum of 8 feet. Clearing the doorway is not the test. The load rating does not replace the projection. The minimum is 8 feet, not 12.Cal. Code Regs., tit. 8, §1735(j)

How often must waste be disposed of from the site under Cal/OSHA's housekeeping rule?

• a.Once at the end of the project, when the site is cleared
• b.Whenever the owner asks for a pickup, since the owner pays for the bins
• c.Once a week on a fixed day, with the volume ignored
• d.At intervals set by the rate of accumulation and the capacity of the job site container✓

All waste shall be disposed of at intervals determined by the rate of accumulation and capacity of the job site container. The rule sets no fixed weekly day. Waiting until the end lets waste accumulate. The interval is not set by the owner.Cal. Code Regs., tit. 8, §1513(f)

How is the compaction of thin fill under the 90 percent exception verified?

• a.By rolling the fill twice
• b.By the contractor's signed statement
• c.By a visual check after rain
• d.By special inspection✓

Compaction shall be verified by special inspection under Section 1705.6. A signed statement is not special inspection. Looking at the fill does not measure density. A number of passes does not measure density.2025 CBC §1804.6

Work has stopped for the day and the chute is idle. What must be done with the discharge end?

• a.It is left open so remaining debris can drain out overnight
• b.It is covered with a tarp that is tied down loosely at the corners
• c.It is closed off securely, or the area is barricaded or fenced✓
• d.It is guarded by one worker who stays on site until the morning

When operations are not in progress, the discharge end shall be securely closed off, or the area barricaded or fenced. An open end lets material fall onto the area. A loose tarp is not a secure closure. Posting a worker overnight is not the rule's method.Cal. Code Regs., tit. 8, §1736(e)

Debris is dropped through floor holes without a chute. When may debris be removed from the lower drop area?

• a.Whenever the pile reaches one foot in height
• b.At a time of the crew's choosing, if workers wear hard hats
• c.Not until debris handling above has stopped✓
• d.After the barricade has been removed

Debris removal shall not be permitted in the lower drop area until debris handling ceases above. Hard hats do not make the area safe while debris is falling. Pile height is not the rule's trigger. The barricade stays while debris is being handled.Cal. Code Regs., tit. 8, §1736(f)

What must be done to a load of debris on a truck before it leaves the site?

• a.It must be weighed on the site's own scale
• b.It must be covered with a tarp that is painted red
• c.It must be secured against displacement✓
• d.It must be limited to the first two trips of the day

Loads on vehicles shall be secured against displacement. The rule is about securement, not site weighing. The color of a tarp is not in the rule. There is no trip limit.Cal. Code Regs., tit. 8, §1593(f)

Where fragmentation of glass is a hazard, how far below the working level must glazed openings be removed?

• a.At least one floor below✓
• b.At least three floors below
• c.After demolition ends
• d.On the working floor

All glazed openings shall be removed at least one floor below the working level. Three floors is more than the rule requires. Glass at the working floor level is a hazard to be dealt with before it. Removal comes as the work proceeds, not after.Cal. Code Regs., tit. 8, §1735(l)

Why should the crew keep a weight ticket or receipt for each load that leaves the site?

• a.To replace the written structural survey required before work
• b.To prove the load was lighter than the truck's rated limit
• c.To document diversion for the permit and local ordinance✓
• d.To avoid the 10-working-day federal asbestos notification

Receipts document where each stream went, which is how diversion is shown to the building department or the local ordinance. Tickets document the destination and weight, not the truck's rating. A ticket is not a structural survey. Tickets do not replace notifications.CalRecycle C&D diversion guidance

Employees must work inside a building that has been damaged by fire and is to be demolished. What does federal OSHA require?

• a.The building is filled with water before entry
• b.The employees wear respirators for a smoke odor
• c.A fire watch stays outside the building
• d.The walls or floor shall be shored or braced✓

When employees work within a structure damaged by fire, flood, explosion or other cause, the walls or floor shall be shored or braced. Respirators do not address collapse. Filling with water does not make it safe. A fire watch does not address collapse.29 CFR 1926.850(b)

May tools or waste be thrown from a building to an area where employees may be located?

• a.Yes, if the landing area has been covered with plywood sheets
• b.Yes, if someone shouts a warning first so people can step away
• c.Not unless the area is guarded by fences, barricades or other means to keep employees out✓
• d.Yes, if each item weighs less than 10 pounds and lands quickly

Waste, materials or tools shall not be thrown from buildings to areas where employees may be located unless the fall area is guarded. A shouted warning is not a guard. The rule sets no weight exception. Plywood on the ground does not keep people out.Cal. Code Regs., tit. 8, §1513(g)

Debris will be dropped through a 3 ft by 3 ft hole with no chute. What is the side length of the enclosed barricaded area below, at a minimum?

• a.9 feet
• b.15 feet✓
• c.12 feet
• d.6 feet

The enclosure must be at least 6 feet back from the projected edge on every side, so 3 + 6 + 6 = 15 feet. Nine feet adds 6 feet on one side only. Twelve feet adds 4.5 feet on each side. Six feet is the setback alone.Cal. Code Regs., tit. 8, §1736(f)

A building has wood floors. From how many floors above grade may flooring boards be removed to create debris storage space?

• a.Not more than three
• b.Not more than one✓
• c.Not more than five
• d.Not more than two

Flooring boards may be removed from not more than one floor above grade, provided falling material does not endanger stability. Three floors is more than the rule allows. Two floors is more than the rule allows. Five floors is more than the rule allows.Cal. Code Regs., tit. 8, §1735(f)(3)

How must material displaced during demolition be handled, unless it is needed for reconstruction?

• a.Stacked on the floor being demolished until the end of the shift
• b.Pushed into the stairwell so the floors stay clear
• c.Left in place until the floor below has been completed
• d.Taken to the ground at once, within the floor's capacity✓

Displaced material shall be transported immediately to the ground, and the amount stored on any floor shall not exceed its safe carrying capacity. Stacking on the demolished floor can overload it. Delay lets debris accumulate. A stairwell is an access route.Cal. Code Regs., tit. 8, §1735(e)

Painted wood siding from a 1950s building is to be removed in demolition. What must the crew consider before treating it as clean wood?

• a.Whether the boards are longer than 8 feet, since long boards are reused first
• b.Whether the boards still have nails, since nails are the main demolition hazard
• c.Whether it contains lead, since the lead standard covers demolition where lead is present✓
• d.Whether the boards are stacked neatly, since neat stacks count as clean wood

The lead standard covers demolition or salvage of structures where lead or lead-containing materials are present. Length does not decide whether wood is lead-painted. Stacking does not address lead. Nails are a hazard, but they are not the question about lead.Cal. Code Regs., tit. 8, §1532.1(a)

An entrance is 10 feet wide. What is the minimum width of its protective canopy?

• a.11 feet
• b.12 feet✓
• c.9 feet
• d.10 feet

The canopy must be at least two feet wider than the entrance, so 10 + 2 = 12 feet. Nine feet is narrower than the entrance itself. Ten feet gives no allowance on either side. Eleven feet gives a half-foot on each side, not the full foot the rule needs.Cal. Code Regs., tit. 8, §1735(j)

What slope away from a building's foundation does the code require for the ground adjacent to it, over how far?

• a.A level grade, so water does not run toward the neighbor, for 10 feet
• b.At least 1 in 100, which is nearly flat, for 2 feet
• c.At least 1 unit vertical in 20 horizontal, for 10 feet✓
• d.At least 1 in 4, which is steep, for 20 feet

The ground adjacent to the foundation slopes away at not less than 5 percent for a minimum of 10 feet. One in 100 is nearly flat and too short a distance. One in 4 is steeper and longer than the rule. A level grade lets water stand near the foundation.2025 CBC §1804.4

A masonry wall section is being taken down above a wood-joist floor. What must the crew avoid?

• a.Leaving the wall in place at the end of the shift, braced
• b.Letting sections fall on floors too weak for the impact✓
• c.Wetting the masonry before it is pushed over to control dust
• d.Starting at the top of the wall and working downward

Sections of walls shall not be allowed to fall on floors supported by wood joists or other floors unable to withstand the impact. Wetting controls dust and is required. Starting at the top is the proper sequence. Leaving walls stable at day's end is required.Cal. Code Regs., tit. 8, §1735(g)

A job produces 45 tons of concrete, and each truck may carry 15 tons. How many loads are needed?

• a.3 loads✓
• b.4 loads
• c.2 loads
• d.30 loads

45 ÷ 15 = 3 loads exactly. Four loads adds a load the division does not need. Two loads would leave 15 tons behind. Thirty loads subtracts 15 from 45.CSLB 13E-21 (03-2026), computation questions