Landscape Design Hardscape Design and Construction 1 — Questions and Answers
Question 1: What is the standard recommended slope for a patio or walkway to ensure proper drainage away from a structure?
- 1 to 2 percent (1/8 to 1/4 inch per foot) (Correct answer)
- 5 to 10 percent
- 0 percent (perfectly level)
- 15 percent
Correct answer: 1 to 2 percent (1/8 to 1/4 inch per foot)
A 1 to 2 percent slope directs water away from buildings while remaining comfortable and safe for foot traffic.
Question 2: Which base material is most commonly used beneath interlocking concrete pavers to provide stability?
- Compacted crushed stone (Correct answer)
- Sand only
- Poured concrete
- Topsoil
Correct answer: Compacted crushed stone
Compacted crushed stone aggregate base provides a stable, well-draining foundation that prevents paver settling and shifting.
Question 3: What is a 'setback' in the context of US hardscape design?
- Required distance from a structure to the property line (Correct answer)
- The depth of a retaining wall footing
- Amount of slope on a driveway
- Distance between stepping stones
Correct answer: Required distance from a structure to the property line
A setback is the minimum distance a structure or paved surface must be located from property lines, as required by local zoning ordinances.
Question 4: What type of retaining wall requires geogrid reinforcement for walls exceeding a certain height?
- Segmental retaining wall (SRW) (Correct answer)
- Dry-stacked stone wall
- Poured concrete wall
- Timber wall
Correct answer: Segmental retaining wall (SRW)
Segmental retaining walls over 4 feet tall typically require geogrid reinforcement extending back into the retained soil for structural stability.
Question 5: What is the purpose of a French drain in a landscape?
- Redirect subsurface water away from an area (Correct answer)
- Provide irrigation to plant roots
- Create a decorative water feature
- Separate lawn from planting beds
Correct answer: Redirect subsurface water away from an area
A French drain is a trench filled with gravel and a perforated pipe that collects and redirects subsurface water to a discharge point.
Question 6: What is the recommended maximum riser height for exterior landscape steps to ensure safety and comfort?
- 7 inches (Correct answer)
- 12 inches
- 4 inches
- 10 inches
Correct answer: 7 inches
Exterior steps should have risers no taller than 7 inches, with a common formula of 2R plus T equals 26 inches guiding comfortable step proportions.
Landscape Design Hardscape Design and Construction 1
What is the standard recommended slope for a patio or walkway to ensure proper drainage away from a structure?