Product Description:

MOT Type 1 is a graded crushed stone sub-base supplied in a 25kg bag, used to form the compacted foundation layer beneath paving, driveways, and hard surfaces. It is laid under block paving, patios and slabs, tarmac and concrete driveways, footpaths, shed and garage bases, and as a foundation beneath garden buildings and hardstanding.

Type 1 works because of how it is graded. The material contains a controlled range of particle sizes from around 40mm down to dust, so when it is compacted the fines fill the gaps between the larger stones and the whole layer locks together into a dense, solid mass with very few voids. That is what carries load and stops a surface sinking, rutting, or developing hollows over time — a sub-base of single-sized stone cannot do the same, as there is nothing to fill the spaces between the pieces.

It must be compacted in layers to work properly. Spread in depths of no more than around 100mm at a time and compact each layer thoroughly with a vibrating plate or roller before adding the next, as material tipped in one deep layer will never consolidate fully and will settle later under the finished surface. Typical depths are around 100mm for footpaths and patios and 150mm or more for driveways and areas taking vehicles, depending on the ground beneath. The 25kg bag suits small repairs, bases for sheds and bins, and jobs too small for a bulk delivery.