Experts in Concrete Patio re-levelling and repairs

How to Level a Sloped or Tilted Patio Safely

Uneven patios can lead to drainage problems, safety concerns, and long-term damage. If your concrete patio has begun to slope in one direction or feels noticeably tilted underfoot, it’s time to take action.

In this guide, we’ll explain the causes behind patio sloping, how to assess the severity, and the safest and most effective methods for restoring a level surface, whether you're lifting individual slabs or rebuilding the base entirely.

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Why Patios Become Sloped or Uneven

Many UK homeowners discover their patio isn't as level as it used to be. Here are the common reasons patios begin to tilt or sink over time, and what each one means for fixing it properly.

Sub-base Settlement

The most frequent cause of patio sloping is movement in the sub-base, the compacted layer beneath the concrete. If the base wasn't installed properly or was laid on soft soil, it may compress or wash away over time, causing one side to sink. This often creates a gradual tilt or 'dip' that gets worse each year. The only permanent fix is lifting the affected section and rebuilding the sub-base correctly.

Drainage or Water Runoff

Poor drainage around the patio can erode the ground beneath one edge of the slab. In areas with clay-heavy or saturated soils, water pooling near the base will eventually cause uneven settling. You may also see moss, algae, or damp patches near the lower side of the patio. Fixing this requires improving runoff with fall adjustments or a perimeter drain.

Heavy Loads Causing Stress

Placing heavy items like hot tubs, stone planters, or outdoor kitchens on one part of the patio can cause it to tilt or sink under stress, especially if the patio wasn’t reinforced. Cracks may also appear near the load-bearing side. Reinforcement or rebuilding that section is usually required to restore levelness and strength.

Safe Methods to Re-Level a Concrete Patio

Lift and Relay Slabs

For paved patios, individual slabs can often be lifted using crowbars or slab lifters.
The sub-base beneath is levelled and re-compacted with MOT Type 1 or sharp sand.
Slabs are then re-laid with proper falls to improve water runoff and surface level.

Foam or Resin Injection (Slab Lifting)

For solid concrete slabs, a technique called polyurethane foam injection can be used to raise sunken sections.
Small holes are drilled, and expanding resin lifts the slab while stabilising the soil beneath.
This is fast, clean, and effective, but suited to minor or moderate level changes (not full slope correction).

Full Removal and Rebuild

In severe cases, the safest option is to break up and remove the entire patio, regrade the base, and start fresh.
This allows for proper slope design, drainage correction, and installation of reinforcement if needed.
Ideal for patios with widespread sloping, poor concrete quality, or unstable subsoil.

Frequently Asked Questions

It can be. Sloped patios increase the risk of trips, poor drainage, and frost damage in low spots. If the slope is worsening or affects access, it should be addressed promptly.

Most patios can be corrected, but the method depends on the cause. Minor dips may be fixed by lifting slabs, while major sloping often requires full replacement.

Foam injection is best for raising small sunken areas. It’s not ideal for correcting a large slope or full-patio tilt, especially if drainage or base issues exist.

Common causes include poor sub-base prep, water damage, soil erosion, or excessive weight. Many UK patios also suffer from freeze-thaw movement or clay soil shifting.

Yes, we offer no-obligation site visits to assess the severity of slope or settlement and recommend the safest and most cost-effective solution for your patio.