Typical depths
Patio sub-base: 100mm of MOT Type 1. Driveway sub-base: 150mm. Paving bed: 30–50mm of grit sand. Decorative gravel: 40–50mm.
Tonnes, not cubic metres
Aggregates are sold by weight. A cubic metre of MOT Type 1 weighs about 2.1 tonnes; gravel about 1.5 tonnes. A bulk bag holds roughly 0.85 tonnes.
Bulk bag or loose?
Up to around 4 tonnes, bulk bags are easiest. Above that, a loose tipper load (up to 20 tonnes) is usually cheaper per tonne.



