The longevity and quality of any hard landscaping — patio, path, driveway or steps — is almost entirely determined by the quality of the groundworks beneath it. A patio laid on inadequate foundations will sink, move and crack within a few years. Done correctly, the same patio should last 20 years or more with minimal maintenance.
Excavation Depth
The required excavation depth depends on what is being laid and the ground conditions. As a general guide, these are the minimum excavation depths for common hard landscaping projects in Hampshire gardens.
- Patio (porcelain or natural stone): 200mm total depth minimum
- Block paving: 250mm total depth minimum
- Gravel path: 150mm total depth minimum
- Driveway (car traffic): 300-350mm total depth minimum
- All depths measured from finished surface level
Sub-base Specification
MOT Type 1 (crushed limestone or granite) is the standard sub-base material for virtually all hard landscaping applications. It must be laid in layers and compacted with a vibrating plate compactor. A depth of 100–150mm of compacted Type 1 is typical for patio applications.
Falls and Drainage
Every hard surface must fall away from the house at a minimum 1:60 gradient. For larger paved areas, consideration should be given to how and where surface water exits — either to a lawn, a planting area or a drainage channel at the paving's edge.
A&T Landscapes carries out thorough groundworks for all hard landscaping projects across Hampshire, Dorset and Wiltshire. Call 07735 916029 for a reliable quote.