CSLB C-27 Landscaping ContractorSite Preparation and DrainageEasy
A landscape contractor is installing a new concrete patio adjacent to a residential foundation. To ensure proper surface drainage away from the structure and prevent water accumulation, what is the minimum recommended slope for the patio surface?
- A1% (1/8 inch per foot)
- B2% (1/4 inch per foot)
- C0.5% (1/16 inch per foot)
- D3% (3/8 inch per foot)
Show answer & explanationAnswer & explanation
Correct answer: B. 2% (1/4 inch per foot)
A minimum slope of 2% (1/4 inch per foot) is widely recommended for hardscape surfaces like patios to ensure positive surface drainage. This prevents water from pooling and directs it away from structures, protecting foundations.
Why the other options are wrong
- A. 1% can be acceptable for very short distances or where drainage is less critical, but 2% is preferred for positive drainage.
- C. 0.5% is generally too flat and may not provide adequate drainage, leading to standing water.
- D. 3% provides excellent drainage but may be perceived as too steep for comfortable use in some patio areas, though it's not incorrect for drainage.
Minimum Patio Slope (Drainage)
The minimum recommended slope for hardscape surfaces like patios, typically 2% (1/4 inch per foot), to ensure positive surface drainage away from structures.
- Prevents water pooling on the surface.
- Directs water away from building foundations.
- Protects structures from moisture damage.
- Aids in keeping surfaces dry and safe.
Memory trick: Two percent, no pooling, keep water sent.