CalcStrip Foundation Calculator
Last updated: 2026-05-09
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| Trench length (m) (m) | Footing width (m) (m) | Footing depth (m) (m) |
|---|---|---|
| 10 m | 0.4 m | 0.5 m |
| 20 m | 0.5 m | 0.6 m |
| 30 m | 0.5 m | 0.7 m |
| 40 m | 0.6 m | 0.8 m |
What is a Strip Foundation?
A strip foundation (continuous footing) is a long, narrow concrete footing that supports load-bearing walls. It spreads the wall load evenly across the soil. Common in residential construction where soil conditions are uniform and loads are moderate.
Volume Calculation
Volume = Length × Width × Depth
Typical strip footings: 0.40-0.80m wide, 0.40-1.0m deep depending on soil bearing capacity and wall load.
Worked Example
Strip foundation 20m long, 0.50m wide, 0.60m deep:
- Volume = 20 × 0.50 × 0.60 = 6 m³
- Cement = 6 × 7 = 42 bags
- Sand = 6 × 0.65 = 3.9 m³
- Gravel = 6 × 0.90 = 5.4 m³
Common Mistakes
- Not excavating below frost line (typically 0.50-1.0m)
- Insufficient width for the soil bearing capacity
- Not compacting the trench base before pouring
- Forgetting to account for stepped foundations on sloped sites
Standards
Calculated per EN 1992-1-1 / EN 1997-1.
Frequently Asked Questions
At least 0.40m below ground level, and below the frost line in cold climates. The depth must also reach soil with adequate bearing capacity.
Yes, longitudinal bars at the bottom of the footing control cracking from differential settlement. Minimum 4 bars of 12mm diameter is typical.
Width depends on the wall load and soil bearing capacity. Typical widths: 0.45m for single-story walls, 0.60m for two-story, up to 1.0m for cavity walls in weak soil.