The foundations beneath any paved surface, wall or structure are the most important element of the job — yet they are invisible once the work is complete. Understanding what good foundations look like and what questions to ask helps you ensure your project is built to last.
Sub-base: The Foundation of All Hard Surfaces
MOT Type 1 crushed limestone or granite is the standard sub-base material for all hard landscaping in the UK. It compacts to a stable, load-bearing surface that distributes weight and resists movement. A minimum depth of 100mm compacted Type 1 is needed for patios; 150–200mm for driveways.
- MOT Type 1: crushed, graded stone that compacts firmly
- Minimum 100mm depth for patio applications
- Minimum 150–200mm for vehicle traffic areas
- Must be compacted with a vibrating plate — not just raked level
- Falls built in at sub-base stage, not corrected at surface level
Mortar Beds vs Adhesive
Natural stone and porcelain paving should be laid on a full mortar bed — a continuous layer of mortar covering the entire underside of each slab. Spot fixing (mortar applied at five points only) is an inferior method that allows slabs to flex and crack. Always specify full mortar bed in your quote.
Drainage Within the Foundation
Any foundation construction must account for drainage. Surface water must have a clear route off the paved area — typically via a fall toward the lawn or a drainage channel. French drains installed beneath or adjacent to paved areas protect the sub-base from waterlogging.
A&T Landscapes builds all hard landscaping on properly specified foundations across Hampshire, Dorset and Wiltshire. Call 07735 916029 for a detailed quote.