Garden Wall Foundation Depth Calculator
Here’s a general guide based on typical garden wall heights, soil types, and other conditions:
| Wall Height | Foundation Depth | Foundation Width | Soil Type | Notes |
|---|---|---|---|---|
| Up to 1 meter (3.3 feet) | 150 - 200 mm (6-8 inches) | 300 - 400 mm (12-16 inches) | Firm soil (e.g., sandy or gravelly) | Most common for small garden walls. Ensure footing is twice the wall thickness. |
| 1 - 1.5 meters (3.3-5 feet) | 200 - 300 mm (8-12 inches) | 400 - 500 mm (16-20 inches) | Firm soil | For walls taller than 1m, consider deeper foundations and wall reinforcement. |
| 1.5 - 2 meters (5-6.6 feet) | 300 - 400 mm (12-16 inches) | 500 - 600 mm (20-24 inches) | Firm soil | Taller walls need deeper and wider foundations for stability. |
| Up to 1 meter | 300 mm (12 inches) | 450 - 600 mm (18-24 inches) | Soft soil (e.g., clay) | Increase foundation depth for soft soils. |
| 1 - 1.5 meters | 400 - 500 mm (16-20 inches) | 600 - 700 mm (24-28 inches) | Soft soil | Greater depth helps compensate for soft or unstable ground. |
| Above 2 meters | Engineering required | Engineering required | Any soil type | Walls taller than 2 meters need professional engineering design for safety. |
Additional Notes:
- Frost Line Consideration: In cold climates, the foundation should extend below the frost line to prevent frost heaving, which may require additional depth (e.g., 600 mm or more).
- Footing Width: A general rule is that the footing should be twice the width of the wall for stability.
- Drainage: Always ensure good drainage around the foundation to prevent water from weakening the structure.
- Reinforcement: For taller walls or unstable soil conditions, reinforcing the foundation with steel or using concrete footings may be necessary.