- +30%clay swells once dug
- 1.9 tper m³ of clay in the ground
- Weightfills a skip before volume
- 12m³per grab lorry load
Muck away by job
Clay or subsoil, 6-yard skips (about 4.6m³), counted by volume only. Bags are 1 tonne builders' bags.
| Job | Dug (in ground) | Loose volume | Weight | 6-yard skips | Or tonne bags |
|---|---|---|---|---|---|
| Shed base 3 × 2m, 150mm | 0.9 m³ | 1.2 m³ | 1.7 t | 1 | 2 |
| Patio 3 × 3m, 200mm | 1.8 m³ | 2.3 m³ | 3.4 t | 1 | 4 |
| Wall footing 10m × 450 × 600mm | 2.7 m³ | 3.5 m³ | 5.1 t | 1 | 6 |
| Patio 4 × 3m, 250mm | 3.0 m³ | 3.9 m³ | 5.7 t | 1 | 6 |
| Drive 6 × 4m, 250mm | 6.0 m³ | 7.8 m³ | 11.4 t | 2 (or 1 grab) | 12 |
The skip counts are by volume. With soil this heavy, ask the hire firm for its weight limit: if it's lower than the weight in the table, you'll need more skips or a grab lorry.
The sum
Loose volume = length × width × depth × 1.3 (clay)
Weight = length × width × depth × 1.9 t
The excavation calculator covers other soils, trenches and post holes, and checks the skips against your hire firm's weight limit.
