Plumbing Exam
Name: _____________________________________ 156 possible points
1. Remodeler P recently moved her bathroom design business to California, and just completed her first design, a guest bathroom addition. The plumbing contractor calls to say that the toilet cannot be installed. Designer P is puzzled as she has specified the same model toilet many times before. What might be the problem? (5 pts.)
1. The local code may not approve the manufacturer of the specified toilet.
2. The local code may have a stringent requirement for gallons per flush, which
is not met by the toilet specified.
3. The plumbing contractor may not know how to install the specified toilet.
4. The plumbing contractor may not be familiar with the national code, which
Supersedes the local code.
2. Remodeler W lives in a community that has just adopted a new plumbing code. The
reason for implementing the new code is to emphasize water conservation and
safety. Which of the following requirements might Designer W expect to see in the
new code? (5 pts.)
A. A pressure balancing valve on the shower.
B. Maximum flow rate in gallons per minute for a shower head.
C. Minimum clearances for lavatories.
D. Maximum gallons per flush for a toilet.
E. Type of materials used for vanity countertops.
1. A,C,D
2. B,C,E
3. B, D, E
4. A, B, D
Figure 4.1 is a drawing of a basic water supply system to provide water to a shower.
In Questions 3,4 and 5, you are to identify various parts of the water supply system.

3. Letter A on the illustration is the: (2 pts.)
1. water supply main, which is providing water to the shower.
2. supply riser, which is venting the shower drain.
3. supply branch, which is providing cold water to the shower.
4. supply branch, which is providing hot water to the shower.
4. Letter B on the illustration is the: (2 pts.)
1. supply riser, which brings the cold water vertically from the supply branch.
2. supply riser, which is venting the shower drain.
3. supply branch, which is providing hot water to the shower.
4. vent stack, which is venting the shower drain.
5. Letter C on the illustration is the: (2 pts.)
1. shutoff valve for the cold water supply.
2. pressure balancing valve for the shower faucet.
3. shutoff valve for the water utility main.
4. shutoff valve for the hot water supply.
6. Remodeler P is conducting a job site inspection for a bathroom remodeling project.
The clients have told her that low water velocity is a problem, and they hope to improve the situation with the new bathroom. During the investigation, Designer P finds:
A. the main supply pipe is ½ in diameter.
B. the existing lavatory does not have a shutoff valve.
C. polybutylene piping for the supply branches.
D. corrosion on fixtures that suggests the supply water is "hard."
Which of these factors could contribute to the low water velocity? (5 pts.)
1. B,C
2. A,D
3. A,C
4. B,D
7. An existing single-head shower will be replaced with a multi-head shower in a
bathroom remodeling project. Can the existing 1/2" supply branch line be used?
(5 pts.)
1. No, because this will not supply adequate .water pressure for the higher demand
multi-head shower.
2. Yes, providing an adapter is used to make the faucet fixtures compatible.
3. No, because the multi-head shower requires a separate supply branch line for
each shower head.
4. Yes, the 1/2" supply may be used as it exists. The number of fixtures is not
affected by pipe size or water volume/ velocity.

8. Remodeler P is working with a plumbing contractor on a bathroom remodeling
project. The contractor mentions he plans to use copper pipe as a supply line.
What are your concerns? (5 pts.)
I. If the water is very hard, copper pipe is not recommended.
2. If the water is very soft, copper pipe is not recommended.
3. If it freezes the pipe will be damaged.
4. All of the above
9. Remodeler W is working on a bathroom addition for a house in northern New
England. The existing house is on a crawl space foundation. Designer W plans to
put the addition on a crawl space and up the outside wall to reach the new fixtures.
The new crawl space foundation will be of cement block, with some blocks
removed to provide ventilation and reduce moisture. What is the problem with this
plan? (5 pts.)
1. Supply pipes on exterior walls are more susceptible to freezing, especially in cold
climates.
2. Crawl space vents should be able to be closed off in winter to help keep the
temperature in the space above freezing.
3.The local code requires copper supply lines, and they will likely corrode if exposed
in an open crawl space.
4. Both 1 and 2.
10. A bathroom addition will include a laundry area. In the plumbing plan, the plumber
recommends extending the hot and cold supply to include a loop or coil of piping
above the connection to the washing machine. Why? (5 pts.)
1. To prevent water hammer.
2. To maintain water pressure.
3. To prevent the pipes from freezing.
4. Both 1 and 2.
11. Remodeler P is working on a bathroom remodeling. The home is on a crawl space
foundation. As part of the job site inspection, Designer P wants to investigate the
crawl space. Why? (5 pts.)
1. It is likely that water supply lines will run through the crawl space and Designer P
wants to know how easily the pipes are accessed for changes.
2. Designer P wants to check the size of the main supply pipe to see if it is large
enough to handle the new water supply requirements.
3. It is not necessary to check the crawl space unless the project will require
foundation repairs.
4. Both 1 and 2.
12. The maximum gallons per flush for toilets is: (5 pts.)
1. 1.2 GPF
2. 4.5 GPF
3. 1.6 GPF
4. 6.7 GPF

13. A dielectric union is a: (5 pts.)
1. special plumbing fitting used when water passes through an electric pump, such
as in a whirlpool bath.
2. special fitting used on an electric water heater.
3. special fitting used to join pipes of two different metals.
4. wire attached to a plumbing pipe, used to allow the plumbing pipe to ground the
electrical system.
14. The required storage capacity of a water heater is determined by all of the
following factors, except: (5 pts.)
1. the number of bathrooms in the home.
2. the square footage of the house.
3. the type of laundry equipment.
4. the recovery rate of the water heater.
15. Remodeler P's client has a family of five and is planning a new home with 2 and ½ bathrooms located on opposite ends of the home. In addition the family has asked the designer if there is a way to minimize the time it takes to flush out the cold water in the hot water supply so that when they turn on the hot water they get it immediately.
What would you recommend? (5 pts.)
1. I would not recommend an on-demand hot water heating system because they require more time to produce hot water than a tank type electric or gas fired hot water heater.
2. I would recommend installing a return line from the plumbing fittings back to the on-demand unit.
3. I would not recommend an on-demand hot water heating system because it could not produce enough hot water for 2 ½ baths.
4. I would recommend two on-demand hot water heating units located near the baths on each end of the house.
5. 1 and 3
6. 2 and 4
16. Two or more body sprays in a mult-head shower require: (5 pts.)
1. Balancing loop
2. ¾” PEX piping
3. 80” ceiling height in shower
4. None of the above
17. "Hard water" is safe to drink. So why might a bathroom designer recommend the
installation of a water softener as part of a remodeling project? (5 pts.)
1. Hard water and soap form a deposit or "scum" on plumbing fixtures and
equipment.
2. Hard water can cause damaging scale build up in water heaters and hot water
supply lines.
3. A bathroom designer should not recommend a water softener as hard water is not
a problem in the bathroom.
4. Both 1 and 2

Household plumbing has two parts: the water supply system and the drain/waste/vent system. Questions 18 and 19 are about understanding the differences between these two systems. Read the following statements, then answer questions 18 and 19.
A. The water is always under pressure.
B. The size pipe that is connected to a fixture is determined by the size and type of
the fixture.
C. There should be a shutoff valve in the pipe connected to each fixture.
D. Water is moved by gravity, and all pipes should have a specified downhill slope.
E. Each pipe should have a trap to hold water and provide a water seal against
sewer gases.
F. Cast iron and ABS and PVC plastics are common materials used for pipes.
G. Copper, galvanized metal, PEX are among the materials used for pipes.
H. Vent lines or stacks are important.
18. Which of the above statements apply to the drain/waste/vent system? (5 pts.)
I. A, B, C, G
2. A,C,G
3. B,D,E,F,H
4. D, E, G, H
19. Which of the above statements apply to the water supply system? (5 pts.) l. A, C, F, H
2. A, B, C, G
3. A,C,G
4. D, E, F, H
Remodeler P's client is planning renovations to a 10-year old home in a rural area.
The home uses a septic tank. The remodeling project will involve: (5 pts.)
1. expanding the second floor master bathroom by replacing a single lavatory with a
new double lavatory in a vanity cabinet and replacing a tub with a multi-head
shower enclosure, and
2. adding a new half bathroom on the first floor.
Questions 20-24 relate to this renovation project:
20. The most important part of the early planning of the project will be which of the
following? (5 pts.)
1. Determining if the septic tank has adequate capacity for the new fixtures.
2. Ordering the vanity cabinet and other plumbing fixtures.
3. Determining if the home has lead water supply lines.
4. Deciding whether to use copper or ABS pipe for the new plumbing.
21. The existing tub has a 1 1/2" diameter drain line with a P-style trap. Will this be
acceptable for the new shower? (5 pts.)
I. Yes, this will meet code.
2. No, a drum-style trap will be needed.
3. No, a larger diameter drain pipe will be needed to handle the large water flow.
4. No, a larger diameter drain pipe will be needed and a more effective S-style trap
will be required.

22. As Remodeler P plans the new double lavatory in the master bathroom, she must
know where the vent stack for the lavatory is located. Why? (5 pts.)
1. To prevent sewer gasses from entering proposed windows
2. The maximum distance from the trap to vent stack for a 1 ¼” lavatory drain is 60"
(5'-0"), which limits lavatory placement.
3. Limited distances between the drain line, trap and vent stack must be maintained,
and thus the vent stack location may dictate the placement of the lavatories.
4. Both 1 and 2.
23. The remodeled master bathroom will have an operable skylight. Designer P consults with the plumbing contractor before determining the exact location of the skylight. Why? (5 pts.)
1. This is just a courtesy so the plumber will feel involved in the project planning.
2. The plumber is knowledgeable about construction and can tell Designer P
where the joists are located.
3. The code requires the vent stack opening to be lower on the roof than a
skylight, and the plumber can advise on the best skylight locations to meet this
requirement.
4. The plumber can verify the location of the vent stack so that Designer P can
meet the code requirements that specify minimum distances between operable
skylight and a vent stack.
24. To accommodate all the plumbing changes, a new waste line will be needed from the master bathroom. This line will run down the wall between the living room and dining room to connect with the main soil and waste line in the basement. The local code is flexible on the choice of materials for DWV lines. Which one of the following would you recommend? (5 pts.)
1. ABS plastic pipe
2. Cast iron pipe
3. Copper pipe
4. PVC plastic pipe
25. You are trying to determine whether a particular thermostatically controlled
shower valve will deliver enough water to a multi head shower and here is what you
know: (5 pts.)
The valve will deliver 14 GPM, you have 5 heads which deliver the max. GPM at 80 psi allowed by the
(you should know this number)
1. Yes the valve will deliver enough water to the shower heads
2. No the valve will not deliver enough water to the shower heads
26. You are re-venting a bath lavatory on the first floor of a two story house. You would tie in the vent to the existing vent at the following location: (5 pts.)
1. 6 “ below the highest fixture in the house
2. 6” above the rim of the sink you are venting on the first floor

3. 6” above the highest fixture in the house
4. None of the above
27. PVC piping is approved for both hot and cold water. (5 pts.)
1. True
2. False
28. Notching the center 1/3 of floor joist for the purpose of running plumbing pipes is allowed by the structural code. (5 pts.)
1. True
2. False
29. The minimum size of a kitchen sink drain is: (5 pts.)
1. 1 ½”
2. 1 ¼”
3. 2”
4. Not regulated