Journeyman Plumber (UPC/IPC) — All Questions

A homeowner hires a plumbing company to replace a water heater and reroute the gas line to it. A journeyman employed by that company will perform the installation. Under a typical adopted plumbing code, who is authorized to apply for and hold the permit?

• a.Any journeyman on the crew, because the journeyman is the person who performs and signs off on the installation
• b.No one, because replacing an existing water heater is a like-for-like repair that never requires a permit
• c.The plumbing inspector, who issues the permit and holds it on the owner's behalf until the final approval
• d.The licensed plumbing contractor responsible for the work, or the owner of a single-family dwelling where the jurisdiction allows an owner-builder exemption✓

A permit is issued to the party who is legally responsible for the work, which is the licensed contractor, and many jurisdictions also allow an owner occupying a single-family home to pull a permit for work on that home. A journeyman performs the work under the contractor's license but is not the permit holder. The inspector enforces the code and approves the work; issuing a permit to himself would defeat that separation. Water heater replacement and any change to gas or water piping is permitted work, while truly minor items such as clearing a stoppage or swapping a faucet are the usual exemptions.IPC §106

Underground drainage piping is installed, and the crew backfills and compacts the trench before the groundwork inspection is called for. What does the code require?

• a.The concealed work must be uncovered and exposed for inspection, and the cost of uncovering and restoring it is borne by the permit holder✓
• b.A reinspection fee is paid and the buried piping is accepted as installed
• c.The inspector may simply carry the groundwork inspection over and then approve the already-buried piping later on at the rough-in inspection stage
• d.The work is accepted if the plumber photographed the piping and the joints before backfilling

Inspections follow a set sequence, typically groundwork or underground, then rough-in or top-out, then final, and no portion of the work may be covered or concealed until it has been inspected and approved. When work is covered early, the code allows the inspector to require it to be uncovered at the permit holder's expense. Photographs are not a substitute for the inspector's own examination and pressure test. Paying a reinspection fee covers the inspector's return trip; it does not buy approval of work no one has seen.IPC §107

Model plumbing codes are published on a three-year cycle. A state adopts one of those editions with statewide amendments, and a city then adopts the state code with additional local amendments. Which document governs an installation in that city?

• a.The manufacturer's installation instructions, which always supersede any adopted code
• b.The most recent model code edition published, whether or not the jurisdiction has adopted it
• c.The model code as published, because the local amendments only apply to commercial work
• d.The edition adopted by the jurisdiction, as amended, since a model code has no legal force until it is adopted✓

A model code is a template with no legal effect on its own; it becomes enforceable only when a state or local jurisdiction adopts it, usually with amendments that reflect local climate, soil and practice. The locally adopted amended edition therefore controls, and the authority having jurisdiction interprets it, with a board of appeals available to hear disputes over that interpretation. Newer published editions do not apply until adopted, which is why a jurisdiction may still be enforcing an edition several cycles old. Manufacturer instructions must be followed for listed and labeled products but cannot override an adopted code requirement.

A drainage, waste and vent system is being water tested. Which statement describes the test correctly?

• a.The system is filled to only a 5 ft head of water and held for just 5 minutes, and a small gradual drop in the level is acceptable as long as no active leak is actually visible anywhere on the piping run being examined by the inspector
• b.All openings are tightly plugged and the system is filled with water to at least a 10 ft head, except for the uppermost 10 ft of the system, and the water level is held for at least 15 minutes with no drop✓
• c.Only the piping below the lowest floor must be filled, and the water must stand for 30 minutes
• d.Water is run through each fixture for 15 minutes while the inspector watches the joints for drips

The water test plugs every opening, fills the system so that at least a 10 ft head of water stands on the section being tested, and requires the level to hold for a minimum of 15 minutes with no loss. The uppermost 10 ft of the system is the recognized exception, since there is no way to put a 10 ft head on the highest piping. A 5 ft head for 5 minutes is not a recognized test, and any drop in the water level means a leak, not an allowable tolerance. Running water through fixtures is a flow check, not a pressure test, and would not reveal a weeping joint under head.IPC §312.2

A high-rise DWV system is water tested in sections. The highest joint in the section currently under test is 28 ft above the building drain, and three more floors of piping continue above that section. To what height above the building drain must the test standpipe extend?

• a.33 ft
• b.38 ft✓
• c.30 ft
• d.28 ft, which is the height of the highest joint in the section under test

The test requires at least a 10 ft head of water on the highest point of the section being tested, so the standpipe must rise 10 ft above that point: 28 ft + 10 ft = 38 ft above the building drain. Stopping at 28 ft puts zero head on the top joint of the section, and 30 ft and 33 ft leave only 2 ft and 5 ft of head. The 10 ft exception for the uppermost portion of the system does not apply here because more piping continues above this section.IPC §312.2

Freezing weather makes a water test impractical, so the DWV rough-in is air tested instead. Which combination of test pressure and duration satisfies the code?

• a.50 psi held for 15 minutes
• b.10 psi held for 30 minutes
• c.5 psi, or a mercury column of 10 in, held for at least 15 minutes with no loss of pressure✓
• d.3 psi, or a mercury column of only 6 in, held for just 10 minutes before the plugs are pulled

The DWV air test uses a uniform gauge pressure of 5 psi, or the equivalent 10 in mercury column, maintained for at least 15 minutes without any drop. Three psi is below the required pressure and 10 minutes is short of the required duration. Ten psi and 50 psi are far above what a drainage system is intended to see; 50 psi is the water supply test value, not the DWV value, and that much air can blow test plugs out of a fitting.IPC §312.3

A water distribution system that will operate at 45 psi working pressure is tested with water. The plumber pumps it to 48 psi, and after 15 minutes the gauge reads 46 psi. How should the result be reported?

• a.Pass, because a small 2 psi drop over the 15 minute test window is within the normal allowable tolerance recognized for a pressurized water supply test on metallic pipe
• b.Pass, because the test pressure of 48 psi exceeded the 45 psi working pressure of the system
• c.Fail, because a water test must hold at not less than the system's working pressure for at least 15 minutes with no drop, and the pressure fell from 48 to 46 psi✓
• d.Fail, because a water supply system may only be tested with compressed air at 100 psi

Under IPC §312.5 the water-supply test is run at not less than the working pressure of the system and held for at least 15 minutes with no loss of pressure; any drop indicates a leak, so a 48 psi start that falls to 46 psi fails. There is no 50 psi floor on a water test: the 50 psi value in §312.5 applies only to the alternative air test permitted for piping other than plastic, not to the water test. Exceeding the working pressure alone (option b) is not a pass once the pressure drops, there is no allowable drop tolerance (option a), and 100 psi compressed air (option d) is not a required method.IPC §312.5

On a set of plumbing drawings, which view shows the vertical arrangement of the DWV piping, the floor-to-floor relationships and the order of the connections, drawn at an angle and generally not to scale?

• a.The floor plan view
• b.The riser or isometric diagram✓
• c.The civil or site utility plan
• d.The fixture schedule

A riser or isometric diagram is a single-line pictorial drawing of the system in three dimensions; it shows what connects to what and at what level but is not drawn to scale, so lengths cannot be measured off it. The floor plan is a scaled overhead view used to locate piping horizontally and to read symbols such as CW, HW, waste and vent. The site plan shows the sewer and water service outside the building along with invert elevations and benchmarks. The fixture schedule is a table of fixture types, models and connection sizes, not a view of the piping.

A floor plan is drawn at a scale of 1/4 in = 1 ft. A straight run of cold water piping measures 3-1/2 in on the drawing. What is the actual length of that run?

• a.3 ft 6 in
• b.17 ft 6 in
• c.14 ft✓
• d.10 ft 6 in

At 1/4 in = 1 ft, every full inch on the drawing represents 4 ft, so 3.5 in x 4 ft = 14 ft. Reading 3 ft 6 in simply repeats the measured inches as feet and ignores the scale entirely. Ten feet six inches comes from multiplying by 3 instead of 4, and 17 ft 6 in comes from multiplying by 5. Checking the answer the other way confirms it: 14 ft x 1/4 in per ft = 3.5 in on paper.

A site plan shows the invert elevation of a building sewer as 102.50 ft at the upstream end and 101.90 ft at the downstream end, with 48 ft of run between the two points. What is the slope of the sewer in inches per foot?

• a.0.125 in per ft
• b.0.15 in per ft✓
• c.0.10 in per ft
• d.0.0125 in per ft

The fall is 102.50 - 101.90 = 0.60 ft, which is 0.60 x 12 = 7.2 in, and 7.2 in divided by the 48 ft run gives 0.15 in per ft. The value 0.0125 is the slope expressed in feet per foot, not inches per foot, so it is off by a factor of 12. One tenth of an inch per foot would produce only 4.8 in of fall over 48 ft, and 0.125 in per ft, the familiar 1/8 in per ft grade, would produce 6 in of fall. Both are plausible-looking but leave the pipe higher than the plan calls for at the connection.

A building sewer runs 62 ft from the building drain to the connection at the main and is to be graded at 1/4 in per foot. The invert elevation at the upstream end is 100.00 ft. What is the invert elevation at the downstream end?

• a.98.45 ft
• b.99.35 ft
• c.98.71 ft✓
• d.101.29 ft

Total fall is 62 ft x 1/4 in per ft = 15.5 in, and 15.5 in divided by 12 is 1.29 ft, so the downstream invert is 100.00 - 1.29 = 98.71 ft. The value 98.45 uses 3/8 in per ft or rounds the fall to 18.6 in. The value 99.35 halves the fall, as if the grade were 1/8 in per ft, and 101.29 applies the fall in the wrong direction, which would run the sewer uphill toward the main.

A crew is setting sewer pipe in a trench 5 ft 6 in deep with vertical walls cut in previously disturbed soil. No sloping, shoring or shielding has been installed. What does OSHA require before a worker enters?

• a.Nothing, because a protective system is required only at 6 ft and greater
• b.The competent person may waive protection if the trench will be open for less than one work shift
• c.A protective system such as sloping, benching, shoring or a trench shield must be in place, because the excavation is 5 ft or more in depth✓
• d.A warning line set back from the top edge of the trench and a dedicated spotter watching the walls for movement are sufficient at this shallow depth

Employees in an excavation 5 ft deep or more must be protected by an adequate protective system, and the only exception is an excavation made entirely in stable rock. The 6 ft figure is a fall-protection threshold, not the trenching trigger. A warning line and a spotter do nothing to stop a wall from collapsing on someone standing in the trench. The competent person can require protection at less than 5 ft when there are signs of a cave-in hazard, but has no authority to waive it based on how long the trench will stay open.29 CFR 1926.652(a)(1)

A trench 7 ft deep with a 3 ft wide bottom is excavated in Type C soil and will be protected by sloping the walls at 1-1/2 to 1. How wide must the excavation be at the top?

• a.17 ft
• b.24 ft✓
• c.13 ft 6 in
• d.10 ft 6 in

Type C soil is sloped 1-1/2 horizontal to 1 vertical, about 34 degrees from horizontal, so each wall lays back 1.5 x 7 = 10.5 ft. Both walls are sloped, giving 3 + 10.5 + 10.5 = 24 ft at the top. The 13 ft 6 in answer adds the layback to only one side, and 10 ft 6 in is the layback of a single wall with the trench bottom left out entirely. Seventeen feet corresponds to a 1 to 1 slope, which is the ratio for Type B soil, not Type C.29 CFR 1926.652(b)

A trench 5 ft deep and 90 ft long is open, with workers spread along its full length installing pipe. What is the minimum number of ladders required and how must they be placed?

• a.Four, one for every 25 ft of trench length
• b.None is required, because a ladder or other means of egress is required only in trenches that are 6 ft deep or greater
• c.Two, placed so that no worker has more than 25 ft of lateral travel to reach a means of egress✓
• d.One, placed at the midpoint of the trench

Trenches 4 ft deep or more need a stairway, ladder, ramp or other safe means of exit located so that a worker travels no more than 25 ft laterally to reach it, so each ladder serves 25 ft in each direction, or 50 ft of trench. Ninety feet therefore needs two ladders, positioned so their 50 ft zones overlap and cover the whole length. The depth trigger is 4 ft, not 6 ft, so doing nothing is a violation. A single ladder at the midpoint leaves workers at the ends 45 ft from egress, and four ladders exceeds what the rule requires.29 CFR 1926.651(c)(2)

A trench must be excavated 22 ft deep in Type B soil to reach an existing sewer main. Which statement about the protective system and the excavated material is correct?

• a.Sloping is prohibited over 20 ft so only a trench box may be used, and the spoil must be kept 1 ft back
• b.The standard tabulated sloping tables may be used at essentially any depth, and the excavated spoil may simply be piled right at the trench edge where it serves as a convenient barrier
• c.The competent person may design the protective system on site at this depth, and the spoil must be kept 5 ft back
• d.A protective system for an excavation deeper than 20 ft must be designed by a registered professional engineer, and excavated material must be set back at least 2 ft from the edge✓

The tabulated sloping, benching and shoring options in the standard stop at 20 ft; anything deeper requires a protective system designed by a registered professional engineer. Spoil, tools and other surcharge loads must be kept at least 2 ft from the edge, or retained by a device that prevents material from falling in. Piling spoil at the edge adds load to the very wall that is most likely to fail, so it is never a barrier. A competent person inspects the excavation daily, before each shift and after rainstorms, but cannot substitute his own judgment for the engineered design a 22 ft trench requires.

Before anyone enters a 12 ft deep sewer manhole classified as a permit-required confined space, the atmosphere is tested and the meter reads 19.2 percent oxygen. What is the correct interpretation, and in what order must the atmosphere be tested?

• a.The reading is acceptable, and the correct order is toxics first, then oxygen, then flammables
• b.The reading is acceptable as long as the entrant wears a filtering facepiece respirator and an attendant is posted
• c.The reading indicates an oxygen-enriched atmosphere, and the correct order is flammables first, then oxygen, then toxics
• d.The reading is oxygen deficient, and the space must be tested for oxygen first, then flammable gases and vapors, then toxic contaminants✓

An acceptable atmosphere holds oxygen between 19.5 and 23.5 percent, so 19.2 percent is oxygen deficient and entry is prohibited until the space is ventilated and retested. Testing follows a fixed order of oxygen, then flammables, then toxics, because combustible gas sensors need oxygen to give a valid reading and a low oxygen result makes the flammability reading unreliable. An enriched atmosphere is above 23.5 percent, not below 19.5. A filtering facepiece only removes contaminants from the air; it cannot add oxygen, so it is never permitted in an oxygen-deficient space, which requires supplied air along with an attendant, a signed entry permit and a retrieval system.29 CFR 1910.146

A plumber is brazing copper joints in a finished mechanical room with combustible wood framing a few feet away. Which practice meets the fire prevention requirements for the work?

• a.A fire extinguisher is kept at the work area and a fire watch is maintained for at least 30 minutes after the torch is shut off✓
• b.The acetylene regulator may be set to 20 psig to speed up the braze as long as the cylinder is chained upright
• c.A fire watch is required only for welding, since brazing and soldering do not produce enough heat to start a fire
• d.Cylinders may be laid on their side while in use provided they are blocked so they cannot roll

Hot work requires suitable fire extinguishing equipment kept ready at the site and a fire watch maintained for at least 30 minutes after the work stops, because smoldering combustibles behind a wall or above a ceiling can take that long to flare up. Acetylene is unstable at pressure and must never be used above 15 psig at the torch. Brazing and soldering both use an open flame and easily ignite framing, insulation and dust, so the fire watch applies to them as well. Cylinders are stored, transported and used upright and secured so the valve cannot be broken off and the acetone in an acetylene cylinder is not drawn into the hose.29 CFR 1926.352

While replacing a section of galvanized water piping in a building from the 1950s, a plumber finds an adjacent steam line wrapped in crumbling fibrous insulation and sees that the old water joints were made with 50/50 tin-lead solder. What is the correct response?

• a.Disturb the crumbling insulation only while wearing an ordinary filtering facepiece dust mask, and reuse the old 50/50 tin-lead solder on the new joints so that they match the rest of the existing system throughout the building
• b.Leave the suspect asbestos insulation undisturbed, stop work in that area and notify the employer or building owner so a licensed abatement contractor can assess it, and make the new joints with lead-free solder✓
• c.Cut the insulation off with a utility knife, bag it, and continue with the repair
• d.Wet the insulation before removing it, since wetting eliminates the need for a licensed abatement contractor

Deteriorating pipe insulation in a building of that era is presumed asbestos-containing until sampling proves otherwise, and the correct action is to leave it alone, keep others out of the area and report it so licensed abatement personnel handle the removal. Cutting, scraping or wetting it yourself still releases fibers and does not make an untrained worker an abatement contractor, and a filtering facepiece does not authorize the work either. On the piping side, 50/50 tin-lead solder is prohibited in potable water systems; solder and flux must be lead free, and wetted surfaces of pipe, fittings and fixtures must not exceed a weighted average lead content of 0.25 percent.

A reduced-pressure principle backflow assembly protecting a boiler feed is required to be:

• a.Tested a single time at installation and then never again
• b.Removed and replaced with a new assembly every year as routine
• c.Tested only if someone later suspects an actual cross-connection
• d.Tested at installation and at least yearly by a certified tester✓

Testable backflow assemblies must be tested when installed and at least once a year (and after any repair) by a certified tester, with the results recorded, because internal check springs and relief valves wear and can fail silently. The device is not replaced wholesale each year, one initial test is not enough, and waiting until a problem is suspected defeats the purpose of scheduled verification.IPC §312.10 / §608.17

Two lengths of hubless (no-hub) cast-iron soil pipe are joined with:

• a.A solvent-cemented bell-and-spigot socket joint
• b.A shielded coupling with a gasket and stainless clamps✓
• c.A tapered threaded coupling made up with pipe dope
• d.A wax sealing ring compressed between the two ends

Hubless cast-iron pipe is joined with a shielded coupling: a neoprene gasket held by a stainless-steel shield and clamp bands, torqued to specification. Solvent cement is for plastic pipe, cast-iron soil pipe is not threaded at the field joint, and a wax ring seals a water closet to its flange, not a pipe-to-pipe joint.ASTM C1277 / CISPI 310

Nonpotable reclaimed (recycled) water distribution piping must be identified how, to prevent a cross-connection with the potable supply?

• a.Left unmarked, since it runs on a completely separate pressure zone
• b.Colored purple and marked nonpotable, with no tie to the potable system✓
• c.Colored the same blue as the potable cold-water distribution piping
• d.Identified only by a wrap of green tape located at the meter

Reclaimed-water piping is colored purple and marked as nonpotable so no one mistakes it for drinking water and cross-connects it to the potable system, which must stay physically separate. Leaving it unmarked, coloring it blue like the cold-water line, or taping only the meter would all invite a dangerous cross-connection.IPC §1301 / UPC §1602

A DWV section is water tested. The highest joint in the section is 24 ft above the building drain, and more piping continues above this section. To what height above the building drain must the test standpipe extend?

• a.10 ft
• b.24 ft
• c.29 ft
• d.34 ft✓

The water test requires at least a 10 ft head on the highest point of the section, so the standpipe must rise 24 + 10 = 34 ft above the building drain (IPC 312.2). Stopping at 24 ft puts no head on the top joint; the 10 ft exception does not apply because piping continues above.

What is the normal sequence of plumbing inspections?

• a.Final, then rough, then groundwork
• b.Groundwork/underground, then rough-in/top-out, then final✓
• c.In any order the contractor prefers
• d.Rough, then final, then groundwork

Inspections follow the order of construction: underground/groundwork first, then rough-in (top-out) before concealment, then the final inspection when fixtures are set (IPC 107). No portion may be covered until it has been inspected and approved.

A floor plan is drawn at a scale of 1/8 in = 1 ft. A run of pipe measures 5 in on the drawing. What is its actual length?

• a.20 ft
• b.64 ft
• c.5 ft
• d.40 ft✓

At 1/8 in = 1 ft, each inch on the drawing equals 8 ft, so 5 in x 8 ft = 40 ft. Reading 5 ft ignores the scale, 20 ft multiplies by 4, and 64 ft multiplies inches the wrong way.

A floor plan is drawn at 1/4 in = 1 ft. A pipe run measures 2-1/2 in on the drawing. What is its actual length?

• a.2-1/2 ft
• b.10 ft✓
• c.5 ft
• d.20 ft

At 1/4 in = 1 ft, each inch equals 4 ft, so 2.5 in x 4 ft = 10 ft. 2-1/2 ft repeats the measured inches as feet, 5 ft multiplies by 2, and 20 ft multiplies by 8.

A site plan shows a sewer invert of 105.00 ft upstream and 104.40 ft downstream over a 40 ft run. What is the slope in inches per foot?

• a.0.018 in per ft
• b.0.125 in per ft
• c.0.18 in per ft✓
• d.0.15 in per ft

The fall is 105.00 - 104.40 = 0.60 ft = 7.2 in, and 7.2 in / 40 ft = 0.18 in per ft. 0.018 is the value in feet per foot (off by a factor of 12), and 0.125 (1/8 in per ft) would give only 5 in of fall over 40 ft.

A building sewer runs 50 ft at 1/4 in per ft. The upstream invert is 100.00 ft. What is the downstream invert elevation?

• a.99.48 ft
• b.98.96 ft✓
• c.101.04 ft
• d.98.75 ft

Fall = 50 ft x 1/4 in = 12.5 in = 1.04 ft, so 100.00 - 1.04 = 98.96 ft. 99.48 ft halves the fall (as if 1/8 in per ft), 101.04 ft runs the sewer uphill, and 98.75 ft rounds the fall incorrectly.

A 8 ft deep trench with a 4 ft wide bottom is dug in Type B soil and sloped at 1 to 1. How wide must the excavation be at the top?

• a.12 ft
• b.24 ft
• c.20 ft✓
• d.16 ft

Type B soil is sloped 1 horizontal to 1 vertical, so each wall lays back 1 x 8 = 8 ft. Both walls sloped gives 4 + 8 + 8 = 20 ft at the top (OSHA 1926 Subpart P, Appendix B). Adding the layback to one side only gives 12 ft, and Type C (1.5:1) would give 24 ft.

A 6 ft deep trench with a 3 ft wide bottom is dug in Type A soil and sloped at 3/4 to 1. How wide must the excavation be at the top?

• a.9 ft
• b.15 ft
• c.12 ft✓
• d.18 ft

Type A soil is sloped 3/4 horizontal to 1 vertical, so each wall lays back 0.75 x 6 = 4.5 ft. With both walls sloped, 3 + 4.5 + 4.5 = 12 ft at the top. Adding one layback gives 9 ft; a 1:1 slope would give 15 ft.

A trench 120 ft long and 5 ft deep has workers along its full length. What is the minimum number of ladders (or other means of egress) required?

• a.3✓
• b.1
• c.2
• d.5

In a trench 4 ft or deeper, a means of egress must be within 25 ft of lateral travel of every worker, so each ladder covers 50 ft of trench (OSHA 1926.651). 120 / 50 = 2.4, rounded up to 3 ladders. Two ladders leave workers more than 25 ft from egress.

How often must the competent person inspect an excavation where workers are exposed?

• a.Daily and before each shift, and after rain or other events that increase hazards✓
• b.Once a week
• c.Once a month
• d.Only at the start of the job

The competent person must inspect the excavation daily and before each shift, and again after any rainstorm or other hazard-increasing event, removing workers if a hazard is found (OSHA 1926.651(k)). Weekly or one-time inspection does not meet the rule.

Before entry into a confined space, the atmosphere reads 23.8 percent oxygen. What does this indicate?

• a.A safe, normal atmosphere
• b.An oxygen-enriched atmosphere, an increased fire and explosion hazard✓
• c.A meter error to be ignored
• d.An oxygen-deficient atmosphere

An acceptable atmosphere is 19.5 to 23.5 percent oxygen, so 23.8 percent is oxygen-enriched, which greatly increases fire and explosion risk and prohibits entry until corrected (OSHA 1910.146). It is neither normal nor deficient, and the reading must not be ignored.

Entry into a permit-required confined space such as a sewer manhole requires:

• a.Nothing special
• b.Only a filtering facepiece respirator and a co-worker standing nearby to watch the entrant
• c.Only a flashlight
• d.An entry permit, an attendant, atmospheric testing, and rescue/retrieval provisions✓

A permit-required confined space entry requires a signed entry permit, atmospheric testing, an attendant posted outside, and rescue/retrieval means, along with any needed ventilation and supplied-air respirators (OSHA 1910.146). A filtering facepiece cannot add oxygen and is not sufficient.

What personal protective equipment is required when cutting or grinding pipe?

• a.Eye and face protection such as safety glasses or a face shield✓
• b.Only gloves
• c.Only a hard hat
• d.No PPE is needed

Cutting and grinding throw chips and sparks, so eye and face protection is required, and a face shield is added over safety glasses for grinding (OSHA 1926.102). Gloves or a hard hat alone do not protect the eyes.

A portable ladder used to access a landing (such as the top of a trench) must extend above the landing surface by at least:

• a.6 in
• b.3 ft✓
• c.6 ft
• d.1 ft

A portable ladder used for access must extend at least 3 ft above the upper landing so a worker has something to hold while stepping off (OSHA 1926.1053). 1 ft or 6 in leaves nothing to grasp at the top.

Portable electric power tools on a construction site must be protected by:

• a.Nothing
• b.GFCI protection (or an assured equipment grounding conductor program)✓
• c.A fuse only
• d.A household power strip

Receptacles supplying portable tools on a jobsite must have ground-fault circuit-interrupter protection, or the employer must run an assured equipment grounding conductor program (OSHA 1926.404). A fuse or a power strip does not protect against electrocution.

Where do you find the hazard and handling information for PVC primer and solvent cement?

• a.The building permit
• b.The plumbing code book
• c.The Safety Data Sheet (SDS)✓
• d.The supplier invoice

The Safety Data Sheet (SDS) provides the flammability, exposure, first-aid, and handling information for chemical products such as primer and cement, and must be available to workers under the Hazard Communication standard (OSHA 1910.1200). The permit and code do not carry that data.

ABS and PVC DWV pipe are joined by:

• a.Solvent cement, using the primer and cement listed for the material✓
• b.Soldered joints
• c.Crimp rings
• d.Threaded joints

Rigid plastic DWV pipe is joined with solvent cement, with PVC requiring a primer and PVC cement and ABS using ABS cement (never interchanged). Threading, soldering, and crimping apply to metal or flexible materials, not solvent-welded plastic.

A hub-and-spigot (bell-and-spigot) cast-iron soil pipe joint is made with:

• a.A compression (rubber) gasket, or molten lead and oakum✓
• b.A wax ring
• c.Pipe-thread dope
• d.Solvent cement

A hub-and-spigot cast-iron joint is made either with a compression rubber gasket pushed into the hub or, in the traditional method, with oakum packing caulked and molten lead poured over it. Solvent cement, wax rings, and thread dope are for other materials and fittings.

Copper tube is joined by:

• a.Solvent cement
• b.Crimp rings only
• c.Threaded joints only
• d.Soldered or brazed joints, or approved press or mechanical fittings✓

Copper tube is joined by soldering or brazing, or with listed press and mechanical fittings (IPC 605). Solvent cement is for plastic, copper water tube is not field-threaded, and crimp rings are a PEX method.

Piping run through a wood stud less than 1-1/4 in from the edge must be protected by:

• a.A larger drill bit
• b.Nothing
• c.A steel nail (shield) plate✓
• d.A wrap of tape

Where a pipe is closer than 1-1/4 in to the edge of a stud or plate, a steel nail plate (shield plate) must cover the area to stop nails and screws from puncturing the pipe (IPC 305.6). Tape provides no such protection.

A pipe that penetrates a fire-rated wall or floor assembly must be:

• a.Left open around the pipe
• b.Wrapped in cloth
• c.Coated with grease
• d.Sealed with an approved firestop system that maintains the fire rating✓

A penetration of a fire-rated assembly must be sealed with a tested, approved firestop system so the assembly keeps its fire-resistance rating (IPC 305 / IBC firestopping). Leaving the annular space open, or stuffing it with cloth, defeats the rating.