What is MOT Type 1?

MOT Type 1 (Ministry of Transport Type 1) is a granular sub-base material made from crushed rock, stone dust, and fines mixed to specific particle size grades. It forms the foundation layer beneath finished surfaces in driveways, car parks, and road construction across Cheltenham and beyond.

The material is defined by a consistent grading curve that combines larger stones with smaller particles and dust. This composition allows MOT Type 1 to compact effectively under mechanical pressure, creating a stable, load-bearing platform. The mixture locks together as it is compacted, reducing settlement and movement that could damage the wearing course above.

Paving contractors use MOT Type 1 because it provides several practical benefits. It distributes weight evenly across the ground, preventing differential settling. The angular nature of crushed stone particles means they lock together tightly when compacted, unlike smooth gravel or shale. For driveway paving projects in particular, a properly compacted MOT Type 1 base determines whether the finished tarmac or block surface will remain level and crack-free over time.

Quality matters in specification. MOT Type 1 must meet British Standard 3882, which sets particle size distribution limits. Material that is too coarse will not compact properly; too fine will trap water. Proper depth (typically 100-150 mm) and compaction to 95-98 per cent density are standard practice for residential and commercial installations.