Wiltshire · England
Underpinning in Wiltshire
If you live in Wiltshire and are looking at underpinning, the first question is why the wall moved. Wiltshire has a mix of ground, with clay in some places and firmer rock in others; ground movement here is more often linked to soils, drains and trees than to mining.
Guide price from£1,050per metre of wall inc VAT
- Area
- Wiltshire
- Pricing region
- South West
- Ground
- Clay in parts
- Towns listed
- 9
What should you know about the ground under Wiltshire?
Southern Wiltshire is chalk, while the north around Swindon, Chippenham and Trowbridge sits on Oxford and Kimmeridge Clays that are prone to seasonal movement near trees. Bath stone was mined underground around Corsham.
Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Wiltshire: stone cottages, railway terraces in Swindon, and large post-war and new-build estates.
Underpinning prices in Wiltshire
Prices in Wiltshire are worked out on South West rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.
| Item | Guide price | Per |
|---|---|---|
| Mass-concrete underpinning | £1,050 – £1,550 | per metre of wall |
| Beam-and-base underpinning | £1,550 – £2,600 | per metre of wall |
| Mini-piled underpinning | £2,050 – £3,600 | per metre of wall |
| Engineer's design and building control feesest. | £825 – £2,600 | per scheme |
How we usually approach underpinning
Mini-piled underpinning
Small-diameter piles are driven or bored down to firm ground and linked by a reinforced beam or needles that pick up the wall. Compact rigs fit through narrow access, and the method reaches depths that would be impractical to excavate by hand.
Best for: Deep soft ground, tree roots, or restricted access
Mass concrete underpinning
The traditional method. Short sections under the wall are dug out in a set sequence, usually about a metre at a time, and filled with concrete before the next section is opened. It suits moderate depths and good access, and it needs little specialist plant.
Best for: Shallow failures on firm ground found at moderate depth
Beam-and-base underpinning
A reinforced concrete beam is cast beneath or alongside the existing footing and carries the wall onto mass concrete bases at intervals. It spreads load well across variable ground and can mean less digging than continuous underpinning along the whole wall.
Best for: Longer runs of wall or heavier loads over variable ground
What happens during underpinning, step by step?
Design and approvals
The engineer produces drawings and calculations. We make the building control or building warrant application, and party wall notices are served where the law requires them, before any digging starts.
Excavation and concrete
Work runs in the sequence the engineer sets so the wall is never left unsupported over a long length. Building control inspects the excavations before concrete goes in, and each section is dry-packed tight to the footing above.
Crack repairs and handover
Once the new foundation has cured, cracks are stitched and repointed, inside walls are made good, and paths or patios disturbed by the dig are reinstated. You receive the building control completion paperwork for your records.
What to look for before calling about underpinning
- One corner of the house visibly lower than the others
- Footings found to be very shallow during a trial pit
- Cracks that keep widening after the drains have been repaired
- Movement continuing through more than one winter of monitoring
Do you need approval for underpinning in England?
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Find underpinning in your Wiltshire town
Questions about underpinning in Wiltshire
Why do houses in Wiltshire crack?
Southern Wiltshire is chalk, while the north around Swindon, Chippenham and Trowbridge sits on Oxford and Kimmeridge Clays that are prone to seasonal movement near trees. Bath stone was mined underground around Corsham. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.
How much will underpinning cost in Wiltshire?
On South West rates, underpinning starts from about £1,050 per metre of wall, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Can I stay in my house during underpinning?
Most people stay at home during external underpinning, because the digging happens outside along the wall. Expect noise, restricted access to that side of the house and some dust. If the work has to be done from inside, through the floor, moving out for part of the job is sometimes advised.
Does underpinning need building control approval?
Yes, underpinning is building work and needs approval and inspections in England and Wales, a building warrant in Scotland, and council building control in Northern Ireland. Inspectors usually check the excavations before concrete is poured. We deal with building control as part of the job.
Does my house really need underpinning?
Often not, because most subsidence is fixed by repairing drains or managing trees and then repairing the cracks. Underpinning is justified when monitoring shows movement continuing after the cause has been dealt with, or when the ground itself is unsuitable. An independent engineer should make that call.