CR-21 Landscapes and Irrigation AZROC
Test Prep EXAM, QUESTIONS WITH
ACCURATE ANSWERS | MULTIPLE
CHOICES || LATEST UPDATED 2026
What is the minimum thickness of brick for the exterior wall of a fireplace?
a) 6 inches
b) 8 inches
c) 10 inches
d) 9 inches -CORRECTANSWER 8 Inches
What is 1/2 inch of accumulated organic material in a grassy area called?
a) mulch
b) ground cover
c) stolons
d) thatch layer -CORRECTANSWER Thatch Layer
What should be provided as a cover for the drain tile before installing the pond liner
where subdrain is used?
a) 4 inches of pea gravel
,b) screen with 1/4 inch mesh
c) a pool grate
d) 8 inches of medium sized rock -CORRECTANSWER 4 inches of pea gravel
How do you properly plant ground cover?
a) in a circular pattern
b) in rows, each row staggered
c) in groups of 2
d) 18 inches apart in rows -CORRECTANSWER In rows, each row staggered
You are going to pour a concrete pad that is 16 feet by 22 feet and 4 inches thick, how
many cubic yards of concrete are needed?
a) 7.3
b) 6.3
c) 3.3
d) 4.3 -CORRECTANSWER 4.3 cubic yards
4.3 cubic yards
4inches ---> 0.333ft
Cubic feet to cubic yards /27
16*22*0.333=117.3333
117.3333/27 = 4.3 cubic yards
,How wide should the footer be for a CMU wall?
a) equal to the width of the block
b) equal to the depth of the frostline
c) three times the width of the block
d) twice the width of the block -CORRECTANSWER Twice the width of the block
How does a contractor know how to fill a trench to a certain grade?
a) by guessing
b) the type of soil
c) by available backfill
d) the specifications -CORRECTANSWER The specifications
How many 8inch x 8inchx16inch concrete masonry blocks will be required for a wall that
is 8 feet 8 inches high and 104 feet long?
a) 936
b) 1088
c) 1124
d) 1014 -CORRECTANSWER 1014 blocks
, 8 feet * 12 inches = 96 inches + 8 inches = 104 inches
104 inches / 8 inches = 13 for height
104 feet * 12 inches = 1248 inches
1248 inches / 16 inches = 78 for length
13 * 78 = 1014 blocks
What is the maximum height above grade of a wooden deck that a CR-21 license may
build?
a) 36 inches
b) 48 inches
c) 18 inches
d) 29 inches -CORRECTANSWER 29 inches
How do you choose a weir?
a) by the cost
b) without calculations, it is better to go with a bigger weir
c) without calculations, it is better to go with a smaller weir
d) by the material used -CORRECTANSWER Without calculations, it is better to go with
a bigger weir
How high can a segmented wall be built?
Test Prep EXAM, QUESTIONS WITH
ACCURATE ANSWERS | MULTIPLE
CHOICES || LATEST UPDATED 2026
What is the minimum thickness of brick for the exterior wall of a fireplace?
a) 6 inches
b) 8 inches
c) 10 inches
d) 9 inches -CORRECTANSWER 8 Inches
What is 1/2 inch of accumulated organic material in a grassy area called?
a) mulch
b) ground cover
c) stolons
d) thatch layer -CORRECTANSWER Thatch Layer
What should be provided as a cover for the drain tile before installing the pond liner
where subdrain is used?
a) 4 inches of pea gravel
,b) screen with 1/4 inch mesh
c) a pool grate
d) 8 inches of medium sized rock -CORRECTANSWER 4 inches of pea gravel
How do you properly plant ground cover?
a) in a circular pattern
b) in rows, each row staggered
c) in groups of 2
d) 18 inches apart in rows -CORRECTANSWER In rows, each row staggered
You are going to pour a concrete pad that is 16 feet by 22 feet and 4 inches thick, how
many cubic yards of concrete are needed?
a) 7.3
b) 6.3
c) 3.3
d) 4.3 -CORRECTANSWER 4.3 cubic yards
4.3 cubic yards
4inches ---> 0.333ft
Cubic feet to cubic yards /27
16*22*0.333=117.3333
117.3333/27 = 4.3 cubic yards
,How wide should the footer be for a CMU wall?
a) equal to the width of the block
b) equal to the depth of the frostline
c) three times the width of the block
d) twice the width of the block -CORRECTANSWER Twice the width of the block
How does a contractor know how to fill a trench to a certain grade?
a) by guessing
b) the type of soil
c) by available backfill
d) the specifications -CORRECTANSWER The specifications
How many 8inch x 8inchx16inch concrete masonry blocks will be required for a wall that
is 8 feet 8 inches high and 104 feet long?
a) 936
b) 1088
c) 1124
d) 1014 -CORRECTANSWER 1014 blocks
, 8 feet * 12 inches = 96 inches + 8 inches = 104 inches
104 inches / 8 inches = 13 for height
104 feet * 12 inches = 1248 inches
1248 inches / 16 inches = 78 for length
13 * 78 = 1014 blocks
What is the maximum height above grade of a wooden deck that a CR-21 license may
build?
a) 36 inches
b) 48 inches
c) 18 inches
d) 29 inches -CORRECTANSWER 29 inches
How do you choose a weir?
a) by the cost
b) without calculations, it is better to go with a bigger weir
c) without calculations, it is better to go with a smaller weir
d) by the material used -CORRECTANSWER Without calculations, it is better to go with
a bigger weir
How high can a segmented wall be built?
