Somerset is known for its heavy clay soils — particularly across South Somerset and the Vale of Taunton Deane. Clay shrinks in dry summers and swells in wet winters, which makes it one of the most challenging soil types for driveways. Get the groundworks wrong and your beautiful new driveway will crack, sink and puddle within 5 years. Get them right and it will last 20–30 years. Here is what we have learned after laying hundreds of driveways across Somerset.
Why Somerset Clay Soil is Problematic for Driveways
Clay soil has two properties that cause driveway problems:
- It shrinks and cracks in dry conditions (especially the dry summers Somerset has been experiencing)
- It swells and becomes soft when saturated — typical in Somerset winters
- It does not drain well, so water sits on the surface and undermines the sub-base
- It has low bearing capacity when wet — meaning it cannot support heavy loads without the right sub-base
The Sub-Base is Everything
On Somerset clay, the sub-base is the most important part of your driveway — more important than the surface material you choose. A proper sub-base for clay soil should include:
- Excavation to 300–400mm depth (deeper than the standard 150mm on stable ground)
- Geotextile membrane laid over the clay to prevent clay migration into the sub-base
- Compacted Type 1 MOT hardcore to 200–250mm thickness
- Wacker plate compaction in layers — not just one pass
- Sand blinding layer for block paving or natural stone
- Adequate edging restraints to prevent lateral movement
Best Driveway Surfaces for Somerset Clay Soil
| Surface | Performance on Clay | Approx Cost per m² (fitted) | Lifespan |
|---|---|---|---|
| Resin bound | Excellent — flexible, SuDS compliant | £70–£110 | 15–25 years |
| Block paving (concrete) | Good — individual units move independently | £65–£95 | 20–30 years |
| Indian sandstone setts | Good — natural flex | £80–£120 | 20–30 years |
| Tarmac (macadam) | Good — flexible surface | £40–£65 | 15–20 years |
| Concrete | Poor on clay — prone to cracking | £50–£80 | 10–15 years on clay |
| Gravel | Poor — washes out, unstable on clay | £20–£35 | 5–10 years |
Note:Concrete is not recommended for Somerset clay soils. Its rigid nature means it cracks as the clay moves beneath it. Resin bound and block paving are our top recommendations — both have flexibility to accommodate seasonal soil movement.
SuDS Compliance — Important for Somerset Driveways
Planning rules require that driveways over 5m² that drain onto the public highway must be permeable (SuDS compliant). This affects many Somerset properties. Resin bound, gravel, and permeable block paving all meet this requirement. Tarmac and concrete do not unless drainage is incorporated. We install SuDS-compliant drainage systems as standard.
Driveway Costs in Somerset — 2026
| Driveway Size | Resin Bound | Block Paving | Tarmac |
|---|---|---|---|
| Small (up to 30m²) | £2,100 – £3,300 | £1,950 – £2,850 | £1,200 – £1,950 |
| Medium (30–60m²) | £3,000 – £5,500 | £2,700 – £4,800 | £1,800 – £3,200 |
| Large (60–100m²) | £4,800 – £9,000 | £4,200 – £8,000 | £2,800 – £5,200 |
All prices above include excavation to the correct depth for Somerset clay, geotextile membrane, full sub-base, edging, and surface material. Do not accept quotes that do not specify the sub-base depth — this is where cowboys cut costs.
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