Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
CR-21 Hardscaping and Irrigation Systems Exam| Questions and Answers| 100% Pass| 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 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 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 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 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 How wide should the footer be for a CMU wall? How does a contractor know how to fill a trench to a certain grade?
Typology: Exams
1 / 154
This page cannot be seen from the preview
Don't miss anything!
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 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 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 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 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. b) 6. c) 3. d) 4.
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 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 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 Without calculations, it is better to go with a bigger weir How high can a segmented wall be built? a) 3 feet b) 6 feet c) 9 feet d) 4 feet 4 feet Which is the most common voltage requirement for the operation of a typical irrigation system remote control valve?
What is necessary to supply power to the electrical source on a water fixture? a) 12-3 wire b) flexible conduit c) 3 phase motor d) schedule 40 conduit Schedule 40 conduit What fitting is used for changing directions with a pipe vertically or horizontally? a) reducing 90 degree threaded elbow b) 90 degree slip elbow c) 90 degree threaded elbow d) reducing 90 degree slip elbow 90 degree slip elbow Which of the following should NEVER be done when transplanting a Balled and Burlapped (B&B) evergreen? a) loosen the burlap around the soil ball b) water deeply when the hole is half full
c) dig the hole 100 percent larger than the soil ball d) apply fertilizer to the soil during conditioning Apply fertilizer to the soil during conditioning What is the minimum distance that a portable heater should be placed away from a wall? a) 24 inches b) 12 inches c) 18 inches d) 36 inches 12 inches What side of a cactus develops a thicker tougher skin due to sun exposure? a) east side b) west side c) south side d) north side South side If pouring concrete and the ground is frozen (or, when the temperature is freezing), what do you do?
What is the required slope of the ground immediately adjacent to a residential structure? a) 1 in 12 for min of 12 feet b) 6 inches for a min of 10 feet c) 1 in 12 for a min of 6 feet d) 2 in 12 for a min of 12 feet 6 inches for a minimum of 10 feet What is the benefit of an as-built plan? a) purchase leverage b) shows where the contractor made mistakes or errors c) selling leverage d) to indicate where lines are for future additions or repairs To indicate where lines are for future additions or repairs What is the maximum size of a bed joint in a masonry wall directly on the foundation? a) 3/8 inch b) 3/4 inch
c) 1/2 inch d) 1/4 inch 3/4 inch How is a post hole dug? a) 3 time wider on the top than the bottom b) about one third larger on the bottom than the top c) about one third larger on the top than the bottom d) same size on the top and bottom About one third larger on the bottom than the top A trench has been prepared for a gray water irrigation line, according to the international residential code, what shall be the minimum depth of the filter material beneath the perforated line? a) 3 inches b) 6 inches c) 12 inches d) 8 inches 6 inches (IRC P3009.10.5)
c) bad water d) reclaimed water Danger-Unsafe Water In the construction of a pond, what is the function of a weir? a) control flow of water from upper to lower pools b) direct the flow of water c) direct the flow of water from the lower to the upper pool d) make the water fall away from the face of the wall Control flow of water from upper to lower pools How far apart should wood planks be installed for expansion? a) 1/8 to 1/4 inch b) 3/8 to 7/16 inch c) 1/16 to 1/8 inch d) 1/2 to 3/4 inch 1/8 to 1/4 inch What is the proper method for installing a wood fence on a slope? a) grade the area
b) step the fence c) follow the slope d) step the slope step the fence You need to trench 50 feet along a utility line. A trenching machine excavates 5 foot in 30 seconds to 1 minute. The trench should be dug? a) slowly and carefully over approximately 5 minutes b) by hand c) last d) in less than 2 minutes By hand What is the spacing for metal joint bracing of a masonry wall? a) every 18 inches b) every 12 inches c) the entire length of the wall d) every 6 inches The entire length of the wall
Nitrogen, phosphoric acid and potash On a long run over 100 feet from a low voltage transformer, what size wire would be best suitable? a) 18- 2 b) 10- 2 c) 12- 2 d) 16- 2 12 - 2 what is fixed reference point called when doing a survey? a) landmark b) reference position c) rod position d) benchmark benchmark You have 2 BCY of sand, after compaction you will have? a) 3.0 CCY b) 1.96 CCY
c) 1.75 CCY d) 2.24 CCY
CCY of sand is 0. 2*0.95 = 1. What technique is used for planting trees but is not normally used when planting shrubs? a) watering b) staking c) mulching d) soil conditioning staking What is the preferred slope for a brick paver walkway in a well-drained area? a) 1/8 inch to 1/4 inch b) 3/8 to 1/2 inch c) 1/4 to 3/8 inch d) 1/2 to 3/4 inch 1/8 to 1/4 inch
b) 3 inches c) 12 icnhes d) 18 inches 6 inches What is the purpose of humus? a) to increase water retention b) to aid in compaction c) to replace sulfur d) to decrease water retention to increase water retention When fertilizing the southwestern garden, among chemical fertilizers, the __ analysis is used most often. a) 5- 10 - 10 b) 20- 10 - 10 c) 4- 10 - 10 d) 4- 12 - 4 4 - 12 - 4
What would you add to soil to increase its' pH value? a) lime b) sulphate c) chelating agent d) wetting agent Lime What is the minimum grade needed for proper drainage? a) less than 1% b) 1% or greater c) less than 3% d) 3% or greater 3% or greater Many shrubs are planted for their flowering qualities and must be pruned at the proper time to realize their maximum potential for flowering. Spring flowering shrubs should be pruned in____ a) fall b) early spring
