Comprehensive Arizona CR21 Hardscaping &
Irrigation Systems Practice Exam ] High-Yield
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Overview: Arizona CR-21 Hardscaping & Irrigation Systems Exam
The Arizona CR-21 (Residential/Commercial) license is a specialty
dual contractor license administered by the Arizona Registrar of
Contractors (ROC) via PSI Services. This license allows contractors
to install, repair, and maintain hardscape features (such as pavers,
retaining walls, and outdoor fireplaces) and pressurized irrigation
systems (including sprinklers, drip systems, and backflow preventers).
To obtain this license, candidates must pass both the Business
Management (SRE) exam and the CR-21 Trade Exam. The trade
exam focuses heavily on plan reading, soil preparation, drainage,
masonry standards for hardscapes, and hydraulic principles for
irrigation.
Key Features of the CR-21 Exam
Primary Reference Materials: OSHA 29 CFR Part
1926, International Plumbing Code (IPC), and various
landscaping/irrigation manuals.
Core Topics:
o Hardscaping: Subgrade preparation, pavers, retaining walls, and
outdoor masonry.
o Irrigation: Backflow prevention, hydraulics, pipe sizing, and electrical
valves.
o Safety: Trenching, ladder safety, and PPE (OSHA standards).
,1. What is the primary purpose of a "backflow preventer" in an
irrigation system?
A. To regulate water pressure
B. To prevent contaminated water from entering the potable water
supply
C. To stop the pump from overheating
D. To filter out sand and debris
Correct Answer: B
Explanation: Backflow preventers are safety devices designed to
ensure that irrigation water, which may contain fertilizers or pesticides,
does not flow backward into the clean drinking water system.
2. In Arizona, what is the minimum depth for a trench housing
pressurized irrigation lateral lines?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Correct Answer: B
Explanation: Standard plumbing and landscaping codes typically
require a minimum of 12 inches of cover for pressurized lateral lines to
protect them from damage.
3. When installing pavers, what is the purpose of the "bedding
sand" layer?
A. To keep weeds from growing
B. To provide a level surface and allow for drainage
C. To act as a decorative grout
D. To prevent the pavers from getting hot
Correct Answer: B
Explanation: Bedding sand (usually 1 inch thick) allows the pavers to
be set evenly and provides a path for water to migrate into the base
material.
4. Which of the following describes "Static Pressure"?
A. Water pressure when the system is running
B. Water pressure when the system is turned off
, C. The weight of the pipe
D. The friction lost in a valve
Correct Answer: B
Explanation: Static pressure is the measure of force per unit area
when the water is not moving.
5. According to OSHA, at what depth must a trench be provided
with a ladder or ramp for egress?
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
Correct Answer: B
Explanation: OSHA 1926.651 requires a safe means of egress for
trenches 4 feet or deeper, with no more than 25 feet of lateral travel.
6. What is the "Rule of Thumb" for the slope of a hardscape patio to
ensure proper drainage away from a house?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: B
Explanation: A 2% slope (1/4 inch per foot) is the industry standard to
prevent water from pooling against the foundation.
7. A "Double Check Valve Assembly" (DCVA) is used in irrigation
when:
A. There is a high health hazard
B. There is only a low health hazard (non-toxic)
C. The system is connected to a well
D. The water is recycled
Correct Answer: B
Explanation: DCVAs are generally used for non-health hazards; high-
hazard systems (containing chemicals) usually require an RP
(Reduced Pressure) zone assembly.
Irrigation Systems Practice Exam ] High-Yield
Questions &Answers Rationales Instant
Download Pdf
Overview: Arizona CR-21 Hardscaping & Irrigation Systems Exam
The Arizona CR-21 (Residential/Commercial) license is a specialty
dual contractor license administered by the Arizona Registrar of
Contractors (ROC) via PSI Services. This license allows contractors
to install, repair, and maintain hardscape features (such as pavers,
retaining walls, and outdoor fireplaces) and pressurized irrigation
systems (including sprinklers, drip systems, and backflow preventers).
To obtain this license, candidates must pass both the Business
Management (SRE) exam and the CR-21 Trade Exam. The trade
exam focuses heavily on plan reading, soil preparation, drainage,
masonry standards for hardscapes, and hydraulic principles for
irrigation.
Key Features of the CR-21 Exam
Primary Reference Materials: OSHA 29 CFR Part
1926, International Plumbing Code (IPC), and various
landscaping/irrigation manuals.
Core Topics:
o Hardscaping: Subgrade preparation, pavers, retaining walls, and
outdoor masonry.
o Irrigation: Backflow prevention, hydraulics, pipe sizing, and electrical
valves.
o Safety: Trenching, ladder safety, and PPE (OSHA standards).
,1. What is the primary purpose of a "backflow preventer" in an
irrigation system?
A. To regulate water pressure
B. To prevent contaminated water from entering the potable water
supply
C. To stop the pump from overheating
D. To filter out sand and debris
Correct Answer: B
Explanation: Backflow preventers are safety devices designed to
ensure that irrigation water, which may contain fertilizers or pesticides,
does not flow backward into the clean drinking water system.
2. In Arizona, what is the minimum depth for a trench housing
pressurized irrigation lateral lines?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Correct Answer: B
Explanation: Standard plumbing and landscaping codes typically
require a minimum of 12 inches of cover for pressurized lateral lines to
protect them from damage.
3. When installing pavers, what is the purpose of the "bedding
sand" layer?
A. To keep weeds from growing
B. To provide a level surface and allow for drainage
C. To act as a decorative grout
D. To prevent the pavers from getting hot
Correct Answer: B
Explanation: Bedding sand (usually 1 inch thick) allows the pavers to
be set evenly and provides a path for water to migrate into the base
material.
4. Which of the following describes "Static Pressure"?
A. Water pressure when the system is running
B. Water pressure when the system is turned off
, C. The weight of the pipe
D. The friction lost in a valve
Correct Answer: B
Explanation: Static pressure is the measure of force per unit area
when the water is not moving.
5. According to OSHA, at what depth must a trench be provided
with a ladder or ramp for egress?
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
Correct Answer: B
Explanation: OSHA 1926.651 requires a safe means of egress for
trenches 4 feet or deeper, with no more than 25 feet of lateral travel.
6. What is the "Rule of Thumb" for the slope of a hardscape patio to
ensure proper drainage away from a house?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: B
Explanation: A 2% slope (1/4 inch per foot) is the industry standard to
prevent water from pooling against the foundation.
7. A "Double Check Valve Assembly" (DCVA) is used in irrigation
when:
A. There is a high health hazard
B. There is only a low health hazard (non-toxic)
C. The system is connected to a well
D. The water is recycled
Correct Answer: B
Explanation: DCVAs are generally used for non-health hazards; high-
hazard systems (containing chemicals) usually require an RP
(Reduced Pressure) zone assembly.
