Loose spoil factor
Excavated ground usually takes more space once dug out. The trench and foundation calculators use a default loose-spoil factor of 1.35, which can be adjusted where the calculator field allows it.
Material density
- Concrete waste is estimated at roughly 2.4 tonnes per cubic metre.
- MOT Type 1 sub-base is estimated using a practical planning density of about 2.2 tonnes per cubic metre.
- Soil, clay, rubble and mixed waste can vary significantly.
Machine recommendations
Recommendations are based on common planning constraints such as access width, haul distance, spoil volume and material type. They do not confirm that a specific model is suitable for a specific site.
Result limits
- Results are rounded for planning conversations, not engineering certification.
- Drainage falls and foundation dimensions must be checked against the actual design requirement.
- Where safety, structural work, public highway, drainage connection or Building Regulations are involved, get competent advice before work starts.