C-53 Swimming Pool exam questions, with answers
10 practice questions for the CSLB Swimming Pool trade exam, each with the answer, a plain explanation and the source it rests on.
These are not real exam questions. CSLB does not release its test questions or answer keys, and nobody else has them. We write our own questions from the C-53 outline and the codes, standards and references CSLB lists for the exam. Each answer names its source so you can check it.
The C-53 exam has 7 sections. The questions below are grouped by section, with the share of the exam each one carries. Read the question, pick an answer, then open “Show the answer”. The other questions of the free test, scored section by section, are in the free 25-question C-53 test.
Planning and Estimating · 21% of the exam
Reviewing plans and specifications; evaluating job sites; obtaining permits; estimating equipment and material costs.
1. Your bid for a pool remodel carries $16,000 in materials, $21,000 in labor and an $8,000 plaster subcontract. Your company marks up each line on its own cost: 20% on materials, 40% on labor and 10% on the subcontract. Using sales price = cost x markup percentage + cost for each line, what is the bid total?
- $49,000
- $55,500
- $56,600
- $57,400
Show the answer
Answer: D. Materials 16,000 x 1.20 = 19,200; labor 21,000 x 1.40 = 29,400; subcontract 8,000 x 1.10 = 8,800; total $57,400. $56,600 leaves the subcontract at cost, $55,500 puts the plain average of the three rates (23.3%) on the $45,000 total, and $49,000 leaves the labor at cost.
Source: Penn State Extension: Sales Price = Cost x Markup Percentage + Cost (applied per cost line)
2. You sign a contract for a new pool with a 68-year-old homeowner at her kitchen table. According to CSLB's Home Improvement Contracts consumer guide, how long does she have to cancel the contract?
- 5 business days
- 3 business days
- 3 calendar days
- 10 business days
Show the answer
Answer: A. The guide says the Contractors State License Law gives the buyer three business days to cancel, or five business days if the buyer is 65 or older; she is 68 and signed at home (the right does not apply to a contract negotiated at the contractor's place of business). 10 days is how long the contractor has to return money after a cancellation, and the period counts business days, not calendar days.
Source: CSLB Home Improvement Contracts guide, Canceling the Contract: Right to Cancel
Swimming Pool/Spa Shell Construction · 32% of the exam
Site preparation and excavation; laying out and setting forms; steel placement and bonding; rough plumbing and electrical; gunite/shotcrete placement and curing.
3. At floor grade of a new shotcrete pool, your excavator uncovers a layer of old roots and buried yard waste. According to ASA Position Statement #6, what must be done before the floor is shot?
- Cover the organic material with plastic sheeting so it cannot touch the shotcrete
- Soak the organic material with water so it is saturated when the floor is shot
- Shoot the floor thicker over the organic material so the shell can bridge it
- Remove the organic material and leave the soil undisturbed or properly compacted
Show the answer
Answer: D. ASA says all organic materials that may decompose and shrink or swell must be removed, with the remaining soil left undisturbed or properly compacted, because the floor rests on that soil. Plastic, extra thickness or soaking leaves the decaying material under the shell.
4. On a cold morning, your gunite (dry-mix) supplier offers an accelerator that contains calcium chloride. According to the ASA technical FAQ on cold-weather shotcrete, what caution applies to that product?
- It may make the mix too stiff to pass through the delivery hose
- It may speed up corrosion of the reinforcing steel in the shell
- It may keep the shotcrete from reaching its final set overnight
- It may react with chlorine in the pool water and etch the plaster
Show the answer
Answer: B. ASA says accelerators can help in cold weather, but caution is advised with accelerators containing calcium chloride because they may accelerate corrosion of reinforcing steel. Accelerators speed setting rather than delay it, and the FAQ does not name hose blockage or plaster etching.
Pool/Spa Systems Installation · 11% of the exam
Plumbing; electrical; equipment installation; solar thermal and photovoltaic; nonconcrete pools and spas; pool covers and water features.
5. You are starting the pump on a pool with a new Hayward SwimClear cartridge filter (manual ISC2030 Rev C). The manual has you open the filter's manual air relief valve before the pump starts. When do you close it?
- When a steady stream of water, not air or air and water, comes out
- When the first spurt of air and water mix comes out of the valve
- When the pressure gauge reads 50 psi with the pump running
- When the pump has run for 30 seconds with the valve open
Show the answer
Answer: A. Hayward says the manual air relief valve must be open before the pump starts and is closed only when a steady stream of water, not air or an air-and-water mix, comes out. 50 psi is the filter's maximum working pressure, not a target, and a fixed number of seconds does not show that the air is out.
Pool/Spa Deck and Shell Finish · 9% of the exam
Decking; interior finish and startup; tile and coping.
6. You are handing a new PebbleFina pool finish over to its owner for start-up brushing. According to Pebble Technology's 2022 start-up and maintenance procedures, which brush should the owner use?
- A brush with mixed nylon and steel bristles
- A brush with stiff polypropylene bristles
- Any common pool brush sold at a store
- Only a brush whose bristles are all nylon
Show the answer
Answer: D. PTI says commonly available pool brushes may be used on PebbleTec, PebbleSheen, PebbleBrilliance and PebbleEssence, but only a 100% nylon brush on PebbleFina and PebbleBreeze. A store brush, stiff polypropylene or steel-mixed bristles are not what PTI allows for this finish.
Commercial Swimming Pools/Spas · 3% of the exam
Title 22 and other code requirements; disabled access features; access ramps and lifts.
7. You are wiring a new spa at a hotel. Under NEC 2023 680.41(A), where must the clearly labeled emergency shutoff switch for the recirculation and jet motors be?
- Within 3 ft of the spa, at the top of its entry steps, readily accessible to users
- At least 5 ft away, inside the locked equipment room, so that only staff can reach it
- At least 10 ft away, at the front desk, where staff can see the whole spa area
- At least 5 ft away, adjacent to and within sight of the spa, readily accessible to users
Show the answer
Answer: D. For spas other than at one-family dwellings, a clearly labeled emergency shutoff or control switch for the recirculation and jet motors must be readily accessible to users, at least 5 ft away, adjacent to and within sight of the spa. A locked room or a distant desk is not accessible to users, and closer than 5 ft is not allowed.
Source: NEC 2023 680.41(A), NEC 2023 (NFPA 70), Article 680 (base of the 2025 California Electrical Code)
Pool/Spa Repair, Renovation, Removal, and Maintenance · 6% of the exam
Water loss and discoloration; structural modifications; equipment and systems (repair, renovation, removal and maintenance).
8. You will drain a backyard pool for a replaster. Under the State Water Resources Control Board's best management practices for residential sources, where should the pool water go?
- Into the street gutter, after letting the chlorine level drop for a day or two in the sun
- Into the sanitary sewer, after calling the local wastewater treatment plant for guidance
- Into the street gutter, after the neighbors on both sides are told when it will be running
- Into the nearest storm drain inlet, after the water is clear and free of any visible algae
Show the answer
Answer: B. The State Water Board's residential BMPs say to discharge swimming pool or spa water into the sanitary sewer and to call the local wastewater treatment plant first for guidance; the other option they give is to dechlorinate the water and reuse it for lawn irrigation. The BMPs aim to keep pool chlorine out of the street and storm drain.
Source: SWRCB MURP Appendix 4E, General Home Maintenance (pool and spa water)
Safety · 18% of the exam
Swimming pool and spa safety; job site safety.
9. You are hanging the gate in the new enclosure around a backyard pool at a single-family home. Under HSC 115923(a) as reprinted in 2025 CBC Section 3109.2, which gate meets the rule?
- Opens away from the pool, self-closing, latch no lower than 60 in above the ground
- Opens toward the pool, self-closing, latch no lower than 60 in above the ground
- Opens away from the pool, self-closing, latch no lower than 48 in above the ground
- Opens toward the pool, self-closing, latch no lower than 54 in above the ground
Show the answer
Answer: A. HSC 115923(a) requires enclosure gates to open away from the pool, be self-closing, and have a self-latching device no lower than 60 in above the ground. 54 in is the release height for self-closing devices on house doors (115922(a)(5)), not the gate latch, and a gate that opens toward the pool does not comply.
10. A hotel manager asks which federal agency enforces the Virginia Graeme Baker Pool and Spa Safety Act drain cover rules at the hotel's pool. According to the 2008 Q&A factsheet for state health agencies on the Act, which agency is it?
- The Occupational Safety and Health Administration (OSHA)
- The Environmental Protection Agency (EPA)
- The Centers for Disease Control and Prevention (CDC)
- The Consumer Product Safety Commission (CPSC)
Show the answer
Answer: D. The factsheet says the CPSC is the federal agency responsible for enforcing the act; it cannot inspect every pool and will mostly investigate reports it receives. OSHA covers workers, EPA covers pesticides and the environment, and CDC gives health guidance, but none of them enforces the VGB Act.
Source: ASTHO Q&A factsheet (2008), Who is responsible for enforcing the act?
Where to go from here
How the license works, from experience to fees: how to get a C-53 license. Everything about the course: the C-53 exam page.
Questions from our free C-53 test, written from CSLB License Examination Study Guide, Swimming Pool (C-53), form 13E-53 (03-2026), for examinations scheduled on or after June 1, 2023. CSLB notes that the percentages are approximate. Reviewed 14 October 2026. Study guidance only; we are not affiliated with CSLB or PSI.