CSLB C-53 Swimming Pool (Trade Exam) — All Questions
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107 questions
An excavation for a pool is 5 feet 6 inches deep in firm clay. What must protect the workers inside?
- a.A warning tape placed around the top edge
- b.A protective system, such as sloping✓
- c.A spotter watching from the top of the hole
- d.A ladder provided for each worker entering
Excavations 5 feet or deeper need a protective system such as sloping, benching, shoring or a shield unless in stable rock. Tape marks the area, a spotter cannot stop a collapse, and a ladder gives egress but no cave-in protection.Title 8 §1541.1(a)
A competent person finds firm cohesive soil, no fissures and no vibration, in a 4-foot-deep pool hole. What may be allowed?
- a.Unprotected sides after a safe finding✓
- b.Skipped examination, since the hole is shallow
- c.Sloping at 2 to 1 in pool excavations
- d.Sloping when the hole exceeds 10 feet
Excavations under 5 feet with a competent person's finding of no indication of cave-in need no protective system. A 2:1 slope is not a rule, 10 feet is invented, and the examination is the condition.Title 8 §1541.1(a)(1)(B)
What is the maximum simple slope in Type A soil, 20 feet or less deep?
- a.1 horizontal to 1 vertical
- b.3/4 horizontal to 1 vertical✓
- c.1/4 horizontal to 1 vertical
- d.1-1/2 horizontal to 1 vertical
Type A allows 3/4:1. The 1:1 slope is Type B, 1-1/2:1 is Type C, and 1/4:1 is steeper than any of the table's soil values.Title 8 §1541.1 App. B, Table B-1
A 10-foot-deep pool hole in Type B soil is cut as a simple slope. How far back is the top edge from the bottom edge on one side?
- a.7.5 feet
- b.10 feet✓
- c.5 feet
- d.15 feet
Type B is 1:1, so the run equals the depth, 10 feet. The 7.5-foot figure is the Type A slope, 15 feet is Type C, and 5 feet is a 1:2 slope.Title 8 §1541.1 App. B
A 6-foot-deep pool hole in Type A soil is sloped at the maximum Type A slope. What is the run on one side?
- a.6 feet
- b.4.5 feet✓
- c.8 feet
- d.9 feet
Type A is 3/4:1, so 6 × 0.75 = 4.5 feet. The 6-foot run is Type B, 9 feet is Type C, and 8 feet inverts the ratio.Title 8 §1541.1 App. B
Which soil is automatically Type C?
- a.Cemented soil such as caliche or hardpan
- b.Stable rock in a natural solid mass
- c.Cohesive soil at 2 tsf that is unfissured
- d.Soil from which water is freely seeping✓
Submerged soil or soil from which water is freely seeping is Type C. Stable rock is its own class and not a soil type, cemented soils like caliche and hardpan are Type A, and cohesive soil at 1.5 tsf or more without disqualifiers is Type A.Title 8 §1541.1 App. A
A pile of spoil is 8 inches from the edge of a 7-foot excavation. What does Title 8 require?
- a.Wet it down so it stays in place
- b.Move it 2 feet back or restrain it✓
- c.Leave it, since 8 inches is enough room
- d.Move it 25 feet back from the edge
Material and equipment must be kept at least 2 feet from the edge or held by retaining devices. Eight inches is too close, 25 feet is not the spoil rule, and wetting does not restrain a pile.Title 8 §1541(j)
A trench-type pool utility excavation is 6 feet deep. How must workers be able to get out?
- a.Waiting at the bottom for rescue
- b.Climbing the sloped bank near the corner
- c.A stairway, ladder or ramp nearby✓
- d.A rope tied off to a parked truck
Trench excavations 4 feet or deeper need a safe means of egress so that no more than 25 feet of lateral travel is required. Bank climbing, a rope on a truck and waiting for rescue are not safe means.Title 8 §1541(c)
Who must inspect an excavation each day and after changes in conditions?
- a.The homeowner
- b.The supplier's sales representative
- c.The delivery driver
- d.A competent person✓
Daily inspections of the excavation, adjacent areas and protective systems are made by a competent person. The owner, driver and sales representative are not designated for that duty.Title 8 §1541(k)
A pool hole has 6 inches of rainwater and is still raining. What does Title 8 say about working in it?
- a.Work may continue if the pump is switched off
- b.Work may continue, since water is a nuisance
- c.Not without adequate precautions✓
- d.Work may continue if boots are worn
Employees may not work in an excavation with accumulated or accumulating water unless adequate precautions protect them. Boots, a switched-off pump and calling it a nuisance do not control the hazard.Title 8 §1541(h)
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Below what oxygen percentage is an excavation atmosphere considered deficient under Title 8?
- a.19.5 percent✓
- b.21 percent
- c.10 percent
- d.25 percent
Atmospheres containing less than 19.5 percent oxygen are deficient. Twenty-one percent is normal air, 25 percent is oxygen-enriched, and 10 percent is not the threshold.Title 8 §1541(g)
Why is a pool excavation hand-dug near a marked gas line?
- a.To keep the hole looking neat and square
- b.To save the cost of running the excavator
- c.To find its exact location by safe means✓
- d.To reduce the volume of soil to haul
When digging approaches an installation's approximate location, its exact location is determined by safe means that prevent damage. Cost, appearance and soil volume are not the reason.Title 8 §1541(b)(3)
Which pre-gunite item concerns the hole itself?
- a.Loose soil left in place as cushioning
- b.A layer of mud left as a working base
- c.Water left in the hole to keep walls damp
- d.Water, mud and loose soil removed✓
The checklist requires the dig to match the plans with standing water, loose soils and mud removed. Water, mud and loose soil all leave a weak or wet subgrade.City builder guide (Menifee)
A site plan shows a pool 5 feet from a lot line and a crew digs 2 feet past the line to fit the steel. What is the problem?
- a.The excavation is temporary, so it is allowed
- b.The spoil will be returned later, so it is allowed
- c.The overdig affects the finish color
- d.The dig goes into the neighbor's land✓
Excavation follows the approved layout and distances to property lines, and over-digging into a neighbor's land is a trespass and stability problem. Temporariness, returning spoil and finish color do not cure it.CSLB C-53 outline (Site preparation and excavation)
What is the first step in excavation planning for an area where gas, water and electric lines may cross the yard?
- a.Probe with the excavator bucket first
- b.Start digging at the corners of the pool
- c.Ask the homeowner where the lines run
- d.Mark and get owners' responses✓
Marking and positive responses from owners of subsurface installations must come before excavation. Corner digging, bucket probing and the owner's memory are not responses from owners.Title 8 §1541(b)(1)
Rain turns a previously stable bank into wet, slumping soil. What does the competent person do?
- a.Let the crew work from the bank edge
- b.Reclassify and clear the workers out✓
- c.Keep the old classification for the day
- d.Add one more ladder and continue
Changing conditions require reinspection and removing employees from the hazard until precautions are in place, and the soil class changes with the soil. Keeping the old class, working at the edge or adding a ladder ignores the hazard.Title 8 §1541(k); §1541.1 App. A
What is a benchmark in pool layout?
- a.A mark showing the owner's preferred pool color
- b.The line between the lawn and the deck
- c.The location of the deepest point of the shell
- d.A fixed elevation used for depths✓
A benchmark is a stable reference elevation from which depths and heights are measured. Color marks, the deepest point and the deck line are not references.CSLB C-53 outline (Lay out and set forms)
A level shows rod readings of 4.20 at the benchmark and 4.80 at the bond beam stake. What does this say?
- a.The stake is 4.80 feet above the benchmark
- b.The stake is level with the benchmark reading
- c.The stake sits 0.60 foot lower than it✓
- d.The stake is 0.60 foot higher than benchmark
A larger rod reading means a lower point, so the stake is 4.80 − 4.20 = 0.60 foot lower. Calling it higher reverses the sign, 4.80 is a reading and not a height, and unequal readings are not level.CSLB C-53 outline (Lay out and set forms)
A 16 by 30 foot layout has both diagonals measured at 34 feet 0 inches. The calculated diagonal is 34 feet 0 inches. What does this mean?
- a.The layout is a trapezoid
- b.The layout is out of square by 2 feet
- c.The layout is square✓
- d.The long side is wrong
The diagonal is the square root of (16^2 + 30^2) = the square root of 1,156 = 34, and measured diagonals that are equal and match the calculation indicate a rectangle. A trapezoid would give unequal diagonals, an error of 2 feet would show up as a difference from the calculated value, and a wrong long side would change the diagonals as well.CSLB C-53 outline (Lay out and set forms)
A crew checks a corner with 6-foot and 8-foot legs. What diagonal indicates a square corner?
- a.12 feet
- b.9 feet
- c.10 feet✓
- d.14 feet
A 3-4-5 triangle scaled by 2 gives 6-8-10. Twelve and 14 are sums or products, and 9 is not the hypotenuse.CSLB C-53 outline (Lay out and set forms)
What does the Building Code say forms for shotcrete shall be?
- a.Flexible and thin sheeting
- b.Substantial and rigid✓
- c.Plain wood boards
- d.Sealed and airtight steel
The code requires forms to be substantial and rigid and built to let air and rebound escape. Flexible forms are not rigid, the code does not limit forms to wood, and airtight forms trap rebound.2025 CBC ch. 19 (shotcrete forms)
Why must forms for shotcrete allow air and rebound to escape?
- a.The shell color would change after curing
- b.Rain would drain out of the forms faster
- c.The concrete would dry sooner in the sun
- d.Trapped rebound and air leave voids✓
Trapped rebound and air prevent full encasement and create defects. Rain drainage, faster drying and color are not the reasons.2025 CBC ch. 19 (shotcrete forms)
What is the role of ground wires in shotcrete work?
- a.Conductors that carry stray current to ground
- b.Ties that join the bonding grid together
- c.Substitutes for the reinforcing steel
- d.Screeds that set thickness, planes and form✓
Ground wires are set as screeds to establish thickness, surface planes and form. They are not electrical grounds, structural steel or the bonding grid.2025 CBC ch. 19 (shotcrete forms)
When can vertical forms generally be removed after shotcrete placement?
- a.Within 5 minutes of placement
- b.The day following installation✓
- c.After 90 days of curing
- d.Before the shotcrete is placed
The shotcrete association says vertical formwork can generally be removed the day following installation. Five minutes after placement is too early, 90 days is excessive, and forms cannot be removed before the shotcrete is placed.American Shotcrete Association Pool FAQ
A soffit form carries the weight of a shotcrete member. What governs its removal?
- a.The surface color has turned gray
- b.The member can carry its weight✓
- c.The crew is ready to move on
- d.The calendar shows the third day
A load-carrying form stays until the member can support its weight. The date, the crew schedule and the color are not the test.American Shotcrete Association Pool FAQ
In a public pool, what is the tolerance on the water level of a pool with a nonadjustable overflow system?
- a.1/2 inch
- b.1 inch
- c.1/8 inch✓
- d.2 inches
The tolerance is 1/8 inch, while other figure dimensions allow up to 2 inches. The larger values are too loose for an overflow edge.2025 CBC §3109B.2
Where must stairs or ramps be provided in a public pool if the pool bottom is more than 1 foot below the deck?
- a.At the deep end of the pool
- b.In the shallow part✓
- c.At each of the four corners
- d.Beside the diving board
Stairs or ramps are provided in the shallowest portion if the drop from the bottom to the deck is over 1 foot. The deep end needs its own second means of entry only in deeper pools, the four corners are not a code location, and a diving board has no tie to entry.2025 CBC §3111B.1
A public pool is 6 feet deep at its deepest. What entry feature does the code require beyond the shallow-end stairs?
- a.A second skimmer near the stairs
- b.A second pump on the equipment pad
- c.A diving platform at the deep end
- d.A second means of entry at depth✓
A second means of entry and exit is required in the deep portion of a pool deeper than 4-1/2 feet. A platform, skimmer or pump does not satisfy it.2025 CBC §3111B.1
A ladder on a public pool is installed 8 inches from the pool wall. What is wrong?
- a.Ladders clear the wall 3 to 5 inches✓
- b.Ladders may sit at varied distances
- c.Ladders must rest on the pool wall
- d.Ladders must clear the wall by 12 inches
The code requires a clearance of not less than 3 inches or more than 5 inches. Any distance, 12 inches and contact all fall outside the range.2025 CBC §3111B.2
What is the minimum tread and width of ladder treads and recessed steps in a public pool?
- a.2 inches tread and 6 inches width
- b.8 inches tread and 20 inches width
- c.5 inches tread and 14 inches width✓
- d.3 inches tread and 10 inches width
Treads and recessed steps have a minimum tread of 5 inches and width of 14 inches. The pairs 2 by 6 and 3 by 10 are smaller than the minimum, and 8 by 20 is larger than the minimum rather than the figure the code names.2025 CBC §3111B.4
What is the maximum distance of a handhold above the waterline in a pool?
- a.24 inches
- b.9 inches✓
- c.18 inches
- d.3 inches below the waterline
Handholds are installed not greater than 9 inches above the waterline. The larger distances exceed the limit.2025 CBC §3112B.1
What clearance to the earth must reinforcing steel maintain at a pre-gunite inspection in one city?
- a.At least 6 inches
- b.At least 3 inches✓
- c.At least 1 inch
- d.At least 1/4 inch
The checklist requires at least 3 inches of clearance to earth. One inch and a quarter inch are too small, and 6 inches is more than stated.City builder guide (Menifee)
ACI 350 requires how much cover over reinforcement for concrete cast against and permanently in contact with ground?
- a.6 inches
- b.1 inch
- c.1-1/2 inches
- d.3 inches✓
The shotcrete association's position statement says ACI 350 requires 3 inches. The smaller values are below it and 6 inches is above it.American Shotcrete Association Position Statement #8
ACI 350 requires at least how much cover for primary bars in floors and walls exposed to earth, liquid or weather, regardless of bar size?
- a.4 inches
- b.1/2 inch
- c.3/4 inch
- d.2 inches✓
The statement says section 12.7 requires a minimum of 2 inches for that exposure. The figures 1/2 inch and 3/4 inch are too thin for earth, liquid or weather exposure, and 4 inches is more than the statement requires.American Shotcrete Association Position Statement #8
A designer wants more than 3 inches of cover on pool steel. What caution does the association give?
- a.Surface crack widths also increase✓
- b.Cover has little effect on cracking
- c.The permit is voided at 3 inches
- d.Thicker cover is the better choice
The statement notes that increasing cover increases crack widths at the surface and suggests considering a maximum of 3 inches. Cover does affect cracking, the permit is not voided at 3 inches, and thicker cover is not simply better.American Shotcrete Association Position Statement #8
What bar spacing center does the association suggest designers try to keep to avoid congestion?
- a.About 18 inches
- b.About 36 inches
- c.About 6 inches✓
- d.About 1 inch
The statement suggests the designer strive for 6 inch centering so intersecting planes are not less than 3 inches. One inch is too tight, and 18 and 36 inches are too open.American Shotcrete Association Position Statement #8
Which reinforcing practice makes it nearly impossible to encase all bars in shotcrete?
- a.Using chairs
- b.Bundling bars✓
- c.Spacing bars at 6 inches
- d.Cleaning the steel
Bundling bars hides individual bars from the shotcrete. Chairs hold the steel off the earth, 6-inch spacing leaves room for the material to flow around each bar, and clean steel bonds, so all three improve encasement.American Shotcrete Association Position Statement #8
According to the association, where are pipes placed relative to shell reinforcement?
- a.On top of the top layer of steel
- b.Outside the shell on the earth side
- c.Beneath the bottom steel on the soil
- d.Between top and bottom steel✓
Pipes are placed between the top and bottom reinforcement. On top of the top steel leaves the pipe without cover, and outside the shell on the earth side or beneath the bottom steel leaves it outside the structural plane.American Shotcrete Association Position Statement #8; ACI 350 §6.3.9
What is the minimum copper wire size a city requires for bonding the pool shell?
- a.#14
- b.#12
- c.#16
- d.#8✓
The builder guide requires a minimum #8 copper wire bonding the shell and terminating at the equipment. The smaller wires are too light.City builder guide (Menifee)
How many bonding wires does a city require for the pool deck at pre-gunite?
- a.A minimum of one wire
- b.A minimum of four wires✓
- c.A minimum of two wires
- d.A minimum of three wires
The guide requires a minimum of four #8 copper wires for the deck bonding. Fewer wires do not meet the minimum, and three is also short of four.City builder guide (Menifee)
What does the equipotential grid equalize?
- a.Pressure across the filter
- b.Voltage between touchable objects✓
- c.Water temperature across the pool
- d.Soil moisture around the shell
The grid exists to avoid significant voltage differences between simultaneously touchable objects. Temperature, moisture and pressure are unrelated.City bonding handout (Menifee), 2022 CEC §680.26
Which of these is bonded in the 2022-code handout's list?
- a.Rubber hose on the pool cleaner
- b.A wooden post free of metal fittings
- c.Metal casings on motors and heaters✓
- d.Plastic return fittings in the shell wall
The list includes metal casings of electrical equipment such as pump motors and heaters. Plastic fittings, rubber hose and wood without metal are not conductive items.City bonding handout (Menifee), 2022 CEC §680.26
Within what horizontal distance of the pool wall must metal parts be bonded, according to the 2022-code handout?
- a.5 feet✓
- b.2 feet
- c.10 feet
- d.25 feet
Metal parts within 5 feet horizontally of the wall and 12 feet vertically above the maximum water level are bonded. A 2-foot limit would leave parts between 2 and 5 feet unbonded, and 10 and 25 feet reach farther than the handout requires.City bonding handout (Menifee), 2022 CEC §680.26(B)
How many points must perimeter surfaces be bonded to the pool's reinforcing steel, uniformly spaced?
- a.Two points around it
- b.One point around it
- c.Three points around it
- d.At least 4 points✓
The handout requires perimeter surfaces bonded at a minimum of 4 points uniformly spaced. Fewer points do not meet the minimum, and 8 is more than the minimum.City bonding handout (Menifee), 2022 CEC §680.26
A vinyl-liner pool has no steel shell. What does the 2019-code handout require?
- a.A conductor attached to the ladder alone
- b.Skipped bonding conductor, since no steel exists
- c.A grid placed under the liner
- d.A bare 8 AWG perimeter conductor✓
For nonconductive shells the handout calls for one minimum 8 AWG bare solid copper conductor along the perimeter contour. Skipping it, bonding only the ladder or a liner grid leaves the plane incomplete.City bonding handout (Menifee), 2019 CEC §680.26
How far from the inside wall does the perimeter conductor run for a nonconductive shell?
- a.Within 18 to 24 inches✓
- b.Within 1 to 2 inches of it
- c.Within 5 to 6 feet of it
- d.Right up against the wall
The conductor follows the perimeter contour within 18 to 24 inches of the inside walls. A distance of 1 to 2 inches or right against the wall is too close to the shell, and 5 to 6 feet is too far out to follow the contour.City bonding handout (Menifee), 2019 CEC §680.26
A deck grid using rebar must use at least what size?
- a.#2 rebar
- b.#1 rebar
- c.#3 rebar✓
- d.#1/2 rebar
The builder guide says a minimum of #3 steel must be used if rebar is used for the deck bonding grid. The smaller sizes are below that minimum.City builder guide (Menifee)
What is the purpose of the 9-square-inch intentional water bond?
- a.To filter debris from the surface
- b.To heat the water in cold spells
- c.To measure the pH of the water
- d.To tie the bonding to the water✓
The intentional water bond is a minimum conductive surface in contact with the pool water that ties the water into the equipotential plane. It does not filter debris, heat the water or measure pH.City bonding handout (Menifee), 2022 CEC §680.26
At pre-gunite, where must the shell bonding wire terminate?
- a.At the pool equipment✓
- b.At the street meter
- c.Inside the house wall
- d.At the fence
The guide requires bonding the shell with #8 copper terminating at the pool equipment. A wire ending at the street meter, inside the house wall or at the fence would not tie the shell to the equipment bonding.City builder guide (Menifee)
Which condition applies to reinforcing steel at the pre-gunite inspection?
- a.Painted white
- b.Free from rust, debris and mud✓
- c.Coated with oil to prevent rust
- d.Left buried in soil
Steel is to be installed per plan, free from rust, debris and mud, and held clear of the earth. Oil, burial in soil and paint are not appropriate.City builder guide (Menifee)