The Landscape Company
Chichester · West Sussex
Chichester’s geology is a blend of chalk, clay, sand and coastal deposits — a combination that can cause movement, drainage problems and long-term structural issues if patios and driveways aren’t built correctly.
This guide explains how subsidence occurs, how to prevent it and the construction methods we use to ensure patios last for decades across Chichester and the surrounding villages, tying in with our drainage & groundworks and tree root & ground movement advice.
Areas like Tangmere, Oving and Donnington sit on clay-heavy soil. Clay expands during wet weather and shrinks during hot summers — causing movement beneath patios and driveways if the retaining walls and edges are not designed with this in mind.
Bosham and Fishbourne often experience high groundwater levels, especially during winter. Poor drainage design can destabilise sub-bases and cause sinking.
Villages near Lavant and Goodwood sit on chalk-based land with occasional soft pockets that require proper compaction and consolidation before any paving is laid.
Roots from oaks, willows and poplars remove moisture from clay, causing rapid shrinkage and ground movement. Our dedicated guide on tree roots & landscape longevity explains how we manage this around patios, paths and garden steps.
Sub-base is compacted in layers using heavy plate compactors or rollers for maximum stability. On steeper plots this often works alongside properly engineered retaining walls.
Used in:
We prevent water sitting under patios by adding:
For more detail on how we handle this, see our Chichester drainage & groundworks guide.
Porcelain requires:
Our comparison of porcelain vs sandstone explains why the build-up is so critical for porcelain in particular.
Prevents surface cracking and movement, especially on large, sun-exposed terraces and long driveway runs.
High water tables, coastal influence and tidal conditions mean soakaways and discharge points must be thought through carefully.
Chalk ground that drains fast but shifts when uncompacted – perimeter details and edge restraint are critical.
Clay-heavy soil that expands and shrinks seasonally, often requiring geogrids, deeper sub-bases and robust edging.
Mixed ground conditions with occasional soft pockets and higher groundwater due to nearby waterways.
Chichester · Bosham · Fishbourne · Lavant · Tangmere · Oving · Donnington · Hunston · Apuldram · Goodwood · Westhampnett · South Downs villages
We specialise in diagnosing ground issues and installing patios built to last — even in challenging coastal and clay conditions. We can also advise how subsidence prevention might affect planning and permitted development rules on sloping or flood-prone plots.
Localised sinking usually points to a soft spot in the original sub-base, shallow excavation, an old drain or poorly compacted fill. In Chichester it can also be caused by clay shrinking back from foundations during dry spells. Our typical fix is to open up the affected area, rebuild the sub-base properly and address any drainage or root issues at the same time.
Not always. Geogrids are most useful where clay is soft, access prevents deep dig-outs, or the area will carry heavier loads such as vehicles. On smaller pedestrian patios with good access and deeper excavation, a well-compacted Type 1 or Type 3 sub-base may be sufficient without reinforcement.
Yes. We carefully lift affected porcelain tiles, rebuild the sub-base and bed, then re-lay using primer and full-bed mortar. If the tiles are discontinued we can often re-design joints or banding so the repaired area blends in with the original layout.
With correct excavation, drainage, sub-base and bedding, a patio should easily last 20–30 years or more, even on clay or coastal plots. Most failures we see in Chichester are due to shortcuts in the unseen build-up rather than the paving material itself.
Explore all of our in-depth landscaping guides for Chichester · Bosham · Fishbourne · Lavant · Tangmere · Oving · Donnington · Hunston · Apuldram · Goodwood · Westhampnett · South Downs villages:
If you’re considering a new driveway, patio or full garden transformation, we’d be happy to talk through your ideas and advise on the best way forward.
Call: 01428 654812 · 07500 877949
Email: richard@tlchaslemere.co.uk
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