London street scene
National Underpinning

Underpinning in London

Surveys, design, and installation across London and surrounding towns.

  • UK-wide coverage and local knowledge
  • 20 year remedial warranty
  • Diagnostics to remedial work

Our London team handles foundation repair across the wider Greater London area. We regularly work in Central, North, South and East and West London boroughs, on Victorian terraces, semi-detached houses, modern builds, and commercial properties.

Local coverage

Every job starts with a free site survey. A chartered structural engineer signs off the design before any work begins, and the installation is backed by a 10-year workmanship guarantee.

Ground conditions in London

very high prevalence

Most of the area sits on London Clay, a stiff, plastic clay that shrinks and swells significantly with seasonal moisture change.

London has the highest subsidence claim rate in the UK, driven by clay shrinkage near mature street trees.

  • London Clay across most boroughs
  • Mature plane and oak trees on Victorian streets
  • Pockets of made-up ground and river terrace gravels near the Thames

Methods we use locally

The right method depends on soil conditions, depth of failure, and access on site. The engineer's design decides, these are the options on the table for London properties.

Method Time on site Best for in London
Beam and base

Reinforced concrete beams that spread the load.

2 to 6 weeks Variable ground, bay windows, redistributing loads. Common on bay windows and settled extensions through South and East and West London boroughs where loads need redistributing along a single elevation.
Foam injection

Lightweight stabilisation that works to depth.

1 day for most jobs Slab re-levelling, void fill, conservatory bases. Useful for re-levelling slabs and floors in East and West London boroughs and Central, where access for excavation is tight and disruption must be kept low.
Mass concrete

The traditional method, done properly.

2 to 6 weeks per elevation Shallow failures on traditional ground, insurance claims. Well-suited to traditional brick properties across London, Central and North where shallow bays can reach competent ground by hand.
Mini piled

When the good ground is a long way down.

1 to 3 weeks on site Deep bearing layers, made-up ground, restricted access. The usual answer for deep clay or made-up ground around London and Central, and for rear-only access through the property.
Resin injection

Targeted ground improvement, no excavation.

1 day for most jobs Granular soils, intact foundations, voids and density loss. Quick non-disruptive fix for shallow void filling and ground stabilisation across Greater London, suited to lighter loads in Central and South.
Screw pile

Helical piles, no concrete cure time.

2 to 5 days Lighter loads, time-critical jobs, conservatories. Low-vibration option for terraces close to neighbours in North and North, with quick installation and minimal spoil.

Areas we cover near London

Central
North
South
East and West London boroughs

Nearby cities

Common questions

Need an opinion on a London property?

A surveyor will be in touch within 48 hours.

Get a free assessment