CSLB C-27 Landscaping ContractorSite Preparation and DrainageMedium
A landscape contractor is tasked with installing a permeable paver system for a new driveway. To ensure effective infiltration and structural integrity, what is the recommended minimum depth of the aggregate base course beneath the bedding layer, assuming a typical residential application with light vehicular traffic?
- A4 inches
- B6 inches
- C8 inches
- D12 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 8 inches
For permeable paver systems in residential applications with light vehicular traffic, an 8-inch aggregate base course is commonly recommended. This depth provides sufficient reservoir capacity for stormwater and structural support for the pavers and traffic loads.
Why the other options are wrong
- A. 4 inches is generally too shallow for a permeable paver base course, offering insufficient water storage capacity and structural support for vehicular traffic.
- B. 6 inches might be acceptable for pedestrian-only permeable applications, but is often insufficient for residential driveways with vehicle loads.
- D. While 12 inches would provide excellent performance, it's typically more than required for residential light vehicular traffic, adding unnecessary material and excavation costs.
Permeable Paver Base Depth
The recommended minimum depth of compacted aggregate base material beneath the bedding layer of permeable pavers, critical for stormwater storage and structural support.
- Provides structural support for traffic loads.
- Creates a reservoir for stormwater infiltration.
- Depth varies with traffic type and soil conditions.
Memory trick: From top to base, water finds its place, eight inches strong, where it belongs.