Hardscape Design Flashcards

What does ADA compliance require for exterior walkway slopes accessible to people with disabilities?

Answer: Maximum 8.33% running slope (1:12) and 2% cross slope

ADA Standards require accessible routes to have a maximum running slope of 8.33% (1:12 ratio) and a maximum cross slope of 2% to accommodate wheelchairs and mobility devices.

Which type of concrete paver pattern is known for its superior interlocking strength and is commonly used for driveways?

Answer: Herringbone (45° or 90°)

The herringbone pattern creates superior interlock between pavers, distributing loads more effectively and resisting lateral movement, making it ideal for driveways and high-traffic areas.

What is 'efflorescence' on masonry or concrete surfaces?

Answer: White salt deposits that migrate to the surface as water moves through masonry

Efflorescence is the white, chalky deposit left on masonry and concrete surfaces when water carries soluble salts to the surface and evaporates, leaving the salts behind.

What is the 'rise and run' formula for designing comfortable outdoor steps?

Answer: Rise + Run = 24 inches (2R + T = 24–26 inches)

The standard formula for comfortable outdoor steps is 2 × Rise + Tread (Run) = 24–26 inches, with typical outdoor steps having a 6-inch rise and 12–15-inch tread.

What is a 'French drain' in landscape hardscape design?

Answer: A subsurface drainage system using a perforated pipe in a gravel-filled trench to redirect groundwater

A French drain is a subsurface drainage solution consisting of a perforated pipe surrounded by gravel in a trench, designed to collect and redirect groundwater away from problem areas.

Which factor is most critical when selecting the thickness of concrete for a residential driveway?

Answer: Anticipated vehicle loads and soil bearing capacity

Concrete thickness for driveways must be designed around anticipated vehicle loads and the bearing capacity of the subgrade soil, with typical residential driveways requiring 4 inches minimum.