Hardcore, MOT Type 1 or Gravel? What to Use for Paths, Bases & Driveways
- 6 days ago
- 3 min read
Choosing the wrong base material is one of the most common - and most avoidable - mistakes in groundworks and landscaping. Get it right and your path, driveway or patio will last for years. Get it wrong and you'll be lifting it within a few seasons.
What's the Difference?
The terms hardcore, MOT Type 1, and gravel or shingle are often used loosely - sometimes interchangeably - but they're not the same thing, and using the wrong one for the wrong application causes real problems.
Hardcore
Hardcore is a general term for broken, crushed, or recycled material used as a sub-base fill - typically crushed concrete, brick rubble, or mixed demolition waste. It's ungraded, which means the particle sizes vary considerably.
It's useful as a bulk fill material to raise levels or fill voids, but it isn't suitable as a finished sub-base on its own. Because it's ungraded, it won't compact uniformly, which means it can shift or settle unevenly under load. Think of it as the rough first layer before a proper sub-base goes in, not the sub-base itself.
Best for: bulk fill, levelling, rough ground preparation
Not suitable for: finished driveways, paving bases, or anywhere that needs consistent compaction
MOT Type 1
MOT Type 1 is a crushed limestone or granite aggregate graded to a specific specification - angular, well-graded particles that lock together and compact tightly under a wacker plate. It's the industry standard sub-base material for driveways, paths, patios, and any paved surface that needs to carry load.
Because the particles are graded and angular (not rounded), they interlock when compacted rather than shifting around. The result is a stable, load-bearing sub-base that won't move.
Standard installation depth is 100–150mm for pedestrian paths and patios, and 150–200mm for driveways, depending on ground conditions and the surface material going on top.
Best for: driveways, paved patios, path bases, shed bases, anywhere paving is being laid
Not suitable for: drainage applications, decorative use, or as a finished surface
Gravel & Shingle
Gravel and shingle are rounded, loose aggregates - and because they're rounded rather than angular, they don't compact and bind the way MOT Type 1 does. That makes them unsuitable as a structural sub-base, but ideal for a range of other applications.
Pea gravel and drainage shingle are commonly used around land drains, soakaways, and as a free-draining layer beneath permeable paving. Decorative gravel and shingle are used as a finished surface for paths, driveways, and borders - low cost, permeable, and low maintenance when laid correctly over a geotextile membrane.
Best for: decorative paths, gravel driveways, drainage layers, soakaways, border infill
Not suitable for: structural sub-bases, under rigid paving, or high-traffic vehicle areas without proper edging and membrane
Quick Reference Guide
Application | Best Material |
Driveway sub-base | MOT Type 1 |
Patio sub-base | MOT Type 1 |
Path sub-base | MOT Type 1 |
Gravel driveway (finished surface) | Gravel / shingle over geotextile |
Decorative garden path | Gravel / shingle |
Drainage layer / soakaway | Drainage shingle |
Bulk fill / level raising | Hardcore |
Under shed base | MOT Type 1 |
A Note on Depth and Compaction
The material is only half the equation. Even the right aggregate will fail if it isn't laid deep enough or compacted properly.
As a general guide:
Pedestrian paths and patios - minimum 100mm compacted MOT Type 1
Driveways (cars) - minimum 150mm, ideally 200mm in softer ground
Always compact in layers of no more than 100mm at a time - don't attempt to compact 200mm in one pass
If you're in any doubt about ground conditions - particularly on clay or in areas with poor drainage - take advice before you start. Getting the sub-base right is far cheaper than relaying a finished surface.
Available at Youngs
We stock MOT Type 1, gravel, shingle and decorative aggregates across our Folkestone, Dymchurch and Biddenden branches, available loose by the tonne or in bulk bags depending on your project size.
Not sure how much you need? Our trade counter staff are happy to help you work out quantities - just bring your measurements along.
