CSLB C-21 Building Moving and Demolition (Trade Exam) — All Questions
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65 questions
A foundation wall is 60 feet long, 9 feet high and 1 foot thick. How many cubic yards of concrete is that?
- a.60 cubic yards
- b.540 cubic yards
- c.6.7 cubic yards
- d.20 cubic yards✓
60 × 9 × 1 = 540 cubic feet, and 540 ÷ 27 = 20 cubic yards. Five hundred forty is the cubic feet. Sixty divides by 9. Six point seven divides by 81.CSLB 13E-21 (03-2026), computation questions
Federal OSHA's demolition subpart addresses selective demolition by explosives how?
- a.It allows the demolition contractor to use explosives with a permit
- b.It limits explosives to buildings of three stories or fewer
- c.It sends the work to the applicable sections of the explosives subpart✓
- d.It prohibits explosives in demolition operations
Selective demolition by explosives shall be conducted in accordance with the applicable sections of subpart U. The section does not leave explosives to the contractor's choice. It does not prohibit explosives. It sets no story limit.29 CFR 1926.860
A job produces 38 cubic yards of debris and the bins hold 12 cubic yards each. How many bin hauls are needed?
- a.5 hauls
- b.26 hauls
- c.3 hauls
- d.4 hauls✓
38 ÷ 12 = 3.17, and a partial bin is still a haul, so the count rounds up to 4. Three hauls rounds down and leaves 2 cubic yards. Five hauls over-counts. Twenty-six subtracts 12 from 38.CSLB 13E-21 (03-2026), computation questions
The 20 cubic yards of concrete in a footing weighs 150 pounds per cubic foot, a figure given in the problem. How many tons does it weigh?
- a.81 tons
- b.40.5 tons✓
- c.3,000 tons
- d.15 tons
20 × 27 = 540 cubic feet, 540 × 150 = 81,000 pounds, and 81,000 ÷ 2,000 = 40.5 tons. Eighty-one is the thousands of pounds. Three thousand multiplies 20 by 150 and skips the conversion. Fifteen is a guess with no basis in the data.CSLB 13E-21 (03-2026), computation questions
A building above the federal thresholds will be demolished after asbestos removal. When must the notice of intention be postmarked or delivered?
- a.On the day demolition begins, if work starts before noon
- b.At least 24 hours before the first worker enters the building
- c.At least 10 working days before asbestos removal or any other activity begins✓
- d.At least 10 calendar days before the demolition permit is issued
Notice is due at least 10 working days before asbestos stripping or removal or other disturbing activity begins. The count is working days, and it runs to the start of work, not the permit. 24 hours is the timing for other notices, not this one. A same-day notice does not meet the rule.40 CFR 61.145(b)(3)(i)
Where in a typical document set would you look first for dust limits, recycling requirements and sequence restrictions on a demolition project?
- a.In the elevation drawings, which show heights and materials
- b.In the specifications, which state methods, limits and restrictions✓
- c.In the title block, which lists the sheet number and date
- d.On the site plan, which shows property lines and utilities
Specifications carry the methods, sequence and performance limits that drawings do not show. A site plan locates things; it does not state limits. A title block identifies the sheet. Elevations give heights and materials, not rules about how to work.2025 CBC §3303.1; CSLB 13E-21 (03-2026)
Who must be in immediate supervision of demolition work at all times?
- a.The building official who issued the demolition permit
- b.The most senior laborer who has done a similar job before
- c.A qualified person with the authority to secure maximum safety✓
- d.The owner of the structure or the owner's representative on site
Demolition work shall be under the immediate supervision of a qualified person with the authority to secure maximum safety for employees. The building official does not supervise the work. Ownership does not make someone qualified or give the needed authority. Seniority alone does not meet the qualified-person standard.Cal. Code Regs., tit. 8, §1734(a)
What is the minimum width of the pedestrian walkway required in front of a demolition site?
- a.6 feet
- b.4 feet✓
- c.5 feet
- d.8 feet
Walkways must be sufficient for the pedestrian traffic and not less than 4 feet wide. Five feet is more than the minimum requires. Six feet is more than the minimum requires. Eight feet is the barrier height, not the walkway width.2025 CBC §3306.2
Which dust control method does Cal/OSHA's demolition section name?
- a.Using water to keep material or debris sufficiently wet✓
- b.Running exhaust fans to blow dust out of the structure
- c.Covering the debris with dry sand at the end of each day
- d.Requiring respirators for the workers within 100 feet
Provisions for dust control shall include the use of water to keep material or debris sufficiently wet, or equivalent steps. Blowing dust out would spread it. Dry sand does not keep material wet. Respirators protect workers but do not control dust at the source.Cal. Code Regs., tit. 8, §1735(t)
Direct cost is $48,000 and the contractor wants a 20 percent margin on price. What is the price?
- a.$60,000✓
- b.$38,400
- c.$57,600
- d.$48,000
Price = 48,000 ÷ 0.80 = $60,000, and 20 percent of $60,000 is $12,000. Fifty-seven thousand six hundred adds 20 percent to cost, a markup. Forty-eight thousand is the cost. Thirty-eight thousand four hundred subtracts 20 percent from cost.CSLB 13E-21 (03-2026), computation questions
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A three-story building has 1,200 square feet of floor space per story and generates 30 pounds of debris per square foot of floor space. How many tons will it generate?
- a.108 tons
- b.36 tons
- c.54 tons✓
- d.18 tons
3 × 1,200 × 30 = 108,000 pounds, and 108,000 ÷ 2,000 = 54 tons. Eighteen tons counts one story and divides wrongly. One hundred eight is the thousands of pounds, not tons. Thirty-six tons counts two stories.CSLB 13E-21 (03-2026), computation questions
A building will be moved onto a new lot. Under the Existing Building Code chapter on relocated buildings, what must the new foundation system comply with?
- a.What the moving contractor's engineer finds adequate, with no code reference
- b.The California Building Code or Residential Code, as applicable✓
- c.The manufacturer's instructions for the jacks used to lift the building
- d.The code in force at the building's original site when it was built
The foundation system of a relocated building shall comply with the Building Code or the Residential Code, as applicable. The chapter points to the current codes for the foundation. An engineer's opinion does not replace the code requirement. Jack instructions say nothing about the receiving foundation.2025 CEBC §1402.2
A two-story building stands 5 feet from an occupied neighbor. Which method choice fits the safety rules?
- a.Removing the ground floor first so the upper floors drop into the basement
- b.Swinging a ball from a long boom to reach the far wall
- c.Pulling the walls over toward the neighbor to save time
- d.Controlled top-down removal, with the neighbor's structure checked✓
Demolition proceeds from the top down, adjacent structures where employees may be exposed are checked, and a ball's boom is kept as short as possible. Pulling walls toward the neighbor endangers it. The rule calls for the boom to be as short as possible. Bottom-first removal violates the top-down rule.Cal. Code Regs., tit. 8, §§1734, 1735; 29 CFR 1926.859
Interior demolition is estimated at 0.05 labor hours per square foot for 3,000 square feet. A crew of 5 works 8-hour days. How many crew days are needed?
- a.150 days
- b.3 days
- c.4 days✓
- d.5 days
3,000 × 0.05 = 150 labor hours, the crew supplies 40 hours per day, and 150 ÷ 40 = 3.75, which rounds up to 4. Three days rounds down and leaves part of the work. One hundred fifty is the labor hours. Five days has no basis in the calculation.CSLB 13E-21 (03-2026), computation questions
When must pedestrian protection be in place at a demolition site?
- a.Before the work of demolishing the building is commenced✓
- b.After complaints are received from pedestrians near the site
- c.After the first floor has been removed and the debris cleared
- d.Within one week after demolition begins, once barriers arrive
The work of demolishing any building shall not be commenced until pedestrian protection is in place. Protection precedes the work and does not wait for the first floor. The requirement does not depend on complaints. A one-week grace period does not exist in the section.2025 CBC §3303.2