EstatePass

Underground & Rough Systems — California C-36 Practice Questions

50 questions · 22% of the C-36 Plumbing Trade exam

Worked questions

4. A water service and sewer cross within a congested trench. Which separation or protection rules govern the layout?

  • AUse paint color as the only protection
  • BLet the pipes touch if both are plastic
  • Apply the required separation and approved crossing or protective details
  • DPlace the water line at the trench bottom for the described plumbing system and documented site conditions

Why C is correct

The best answer is: Apply the required separation and approved crossing or protective details. Separation and crossing requirements reduce the chance that sewage contamination reaches potable piping during leakage or repair. Pipe material or color alone does not manage that public-health hazard. The transferred field condition applies the same plumbing design, installation, service, or safety principle to a different project setting. The alternatives omit a prerequisite, conflict with the approved method, or fail to control the stated sanitation or physical hazard.

5. Petroleum-contaminated soil surrounds a planned water-service route. Which material and routing issue needs approval?

  • AA thinner pipe wall
  • Material suitability and an approved protective routing or method
  • COnly the pipe's exterior color for the described plumbing system and documented site conditions
  • DHigher water temperature

Why B is correct

The best answer is: Material suitability and an approved protective routing or method. Some contaminants can permeate or degrade piping and joining materials. Site conditions, manufacturer limitations, health protection, replacement soil, sleeving, or rerouting require design and authority review. The transferred field condition applies the same plumbing design, installation, service, or safety principle to a different project setting. The alternatives omit a prerequisite, conflict with the approved method, or fail to control the stated sanitation or physical hazard.

6. Three underground systems converge at similar elevations. Which verification prevents a wrong material or system connection?

  • AUse the shortest pipe for every system for the described plumbing system and documented site conditions
  • BConnect by outside diameter alone
  • Verify layout, elevation, material, and identity before joining
  • DWait until fixtures fail

Why C is correct

The best answer is: Verify layout, elevation, material, and identity before joining. Similar-looking piping can serve potable, reclaimed, gas, drainage, or fire systems with different requirements. Positive identification and coordinated layout prevent cross-connections and costly concealed rework. The transferred field condition applies the same plumbing design, installation, service, or safety principle to a different project setting. The alternatives omit a prerequisite, conflict with the approved method, or fail to control the stated sanitation or physical hazard.

44 more in the bank

Answers and explanations for these are in the app.

  • A drainage branch is roughed in so the trap arm will fall vertically before reaching its vent connection. What must be checked?
  • A drainage cleanout is installed where its opening faces a permanent wall at close range. What should be corrected?
  • A drainage run passes its leak test but moves off grade during initial backfill. What should be done?
  • A long hot-water run is tightly anchored at both ends with no movement provision. What issue should be addressed?
  • A metallic underground gas-pipe system is proposed without corrosion protection. What must be verified?
  • A pressurized underground water line changes direction at a fitting and the joint system does not resist thrust by itself. What must be provided?
  • A proposed water-service route conflicts with the building sewer in the same trench. What should guide the layout?
  • A quick-closing valve serves a long branch. Which rough-in provision may be required to control pressure shock?
  • A required underground cleanout will be covered by a permanent concrete slab with no access. What must change?
  • A vent is routed so condensate can collect in a sag. What correction is appropriate?
  • A water pipe passes through a concrete foundation where movement and corrosion can damage it. What is required?
  • A water service is installed in soil known to be contaminated by petroleum. What must be evaluated?
  • A water test level falls during rough inspection, but no leak is visible. What is the next step?
  • An underground horizontal drain has a reverse-grade section before the building sewer connection. What must occur?
  • Different underground piping systems cross in a congested excavation. What field control best reduces wrong connections?
  • Excavated backfill contains large debris that could bear directly on plastic drainage pipe. How should it be handled?
  • Horizontal plastic drainage piping is supported only at fittings. What must be verified?
  • Multiple pipes penetrate a rated floor assembly. What is required at rough-in?
  • Plastic water pipe passes through a concrete footing. What must the penetration detail prevent?
  • Underground drainage pipe is resting on isolated rocks with voids beneath several joints. What should be corrected before backfill?
  • Utility markings differ from record drawings along a sewer route. What should occur before mechanized excavation continues?
  • Why must appliances and components not rated for a fuel-gas test pressure be isolated?
  • A cleanout faces a permanent wall with too little room for service tools. Which layout correction is required?
  • A long branch serves a solenoid valve that closes almost instantly. Which rough-in device may control the pressure wave?
  • A pipe passes through concrete where settlement and abrasion can damage it. Which penetration detail is appropriate?
  • A required cleanout ends beneath a future fixed cabinet and slab edge. How should its termination be revised?
  • A survey finds a short uphill section in a gravity building drain. What must be done before connection?
  • A tightly restrained hot-water main has no allowance for temperature growth. What resulting stress must be addressed?
  • A trap arm drops vertically before reaching its vent takeoff. Which rough-in principle is threatened?
  • A vent line sags between supports and holds condensate. How should it be graded and supported?
  • An underground drain bridges rock points with empty spaces below its joints. What bedding correction is required before testing?
  • An underground water test loses pressure with no visible surface leak. What diagnostic step should precede approval?
  • An unrestrained pressure elbow changes direction in a buried water main. What must resist hydraulic thrust?
  • Bare metallic gas piping will contact aggressive soil. Which corrosion-protection design must be verified?
  • Cold piping above a humid occupied ceiling develops condensation. Which insulation and vapor treatment is appropriate?
  • Different pipe materials penetrate a rated floor assembly. What determines the approved firestop installation?
  • Excavated chunks and construction debris are proposed as initial cover over plastic pipe. What backfill practice is required?
  • Field marks and record drawings disagree along a proposed trench. What must happen before powered excavation resumes?
  • High test pressure could reach appliance controls not rated for it. Why must they be isolated from the gas test?
  • Initial backfill pushes a tested sewer off its designed slope. What must be restored before cover continues?
  • Plastic horizontal drainage is supported only at changes of direction. What support and movement checks are required?
  • Plastic water pipe crosses a footing penetration. What damage and load transfer must the sleeve prevent?
  • Soft disturbed pockets remain in the sewer trench bottom. What support must be prepared before pipe placement?
  • The crew plans to cover a new sewer immediately after assembly. When may approved backfill proceed?

Practice all 50 Underground & Rough Systems questions

Plus timed mock exams and a wrong book that follows you between the web and the app.

Start studying free

Other California C-36 content areas