Portsmouth · Hampshire
Underpinning in Portsmouth
Underpinning a house in Portsmouth starts with proof that it is needed, not with a digger. An independent engineer looks at the monitoring and ground investigation, then chooses between mass concrete, beam-and-base or mini-piles for that particular wall and soil.
Guide price from£1,100per metre of wall inc VAT
- Postcodes
- PO1, PO2, PO5
- Population
- about 210,000
- Area
- Hampshire
- Pricing region
- South East
What should you know about the ground under Portsmouth?
Portsmouth is in Hampshire and takes in postcode districts PO1, PO2, PO5. About 210,000 people live there. Neighbouring towns we cover: Fareham (5 miles), Hayling Island (5 miles) and Havant (6 miles).
Shrinkable clay is widespread in Hampshire. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Hampshire: Victorian terraces in Portsmouth and Southampton, 1930s semis, and large post-war and new-build estates.
Signs you may need underpinning
- A large tree nearby that cannot be removed or reduced
- Floors sloping noticeably towards one external wall
- Footings found to be very shallow during a trial pit
How much will underpinning cost in Portsmouth?
The ranges below reflect typical South East costs for underpinning, including VAT. Scaffold, access and making good can push a job to the top of the range.
| Item | Guide price | Per |
|---|---|---|
| Mass-concrete underpinning | £1,100 – £1,700 | per metre of wall |
| Beam-and-base underpinning | £1,700 – £2,800 | per metre of wall |
| Mini-piled underpinning | £2,250 – £3,900 | per metre of wall |
| Engineer's design and building control feesest. | £895 – £2,800 | per scheme |
Which repair method suits a home in Portsmouth?
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
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 when we carry out underpinning in Portsmouth?
Engineer’s investigation
An independent chartered structural engineer studies the monitoring results, trial pits and soil tests, then decides whether underpinning is needed and which method suits. We can arrange the engineer if you do not already have one.
Fixed written price
With the design in hand we confirm a fixed price in writing, setting out the method, the length of wall, access arrangements and the making good. For insurance work we can price to the loss adjuster’s or engineer’s schedule.
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.
Rules 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.
Underpinning in Portsmouth: questions and answers
How much will underpinning cost in Portsmouth?
Guide prices for underpinning in Portsmouth start from about £1,100 per metre of wall, including VAT, on South East rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Portsmouth?
Yes. We take enquiries from across Portsmouth, including PO1, PO2, PO5, and from nearby places such as Fareham and Hayling Island. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Hampshire prone to subsidence?
Central Hampshire is chalk, while the south around Portsmouth, Southampton and the New Forest fringe and the north-east around Farnborough sit on London Clay, Reading Beds and other clays and sands. The clay areas see seasonal movement near trees. Only an investigation can say why a particular building has moved.
Can you underpin only part of a house?
Yes, partial underpinning of one corner or one wall is common, though the engineer must think about the junction with the unstrengthened part. A sudden change in foundation depth can cause new cracking, so the scheme may step down gradually or include a movement joint.
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.
Other structural repairs in Portsmouth
- Brick arch repairs
- Resin injection ground stabilisation
- Retaining wall repairs
- Concrete repairs
- Boundary and garden wall repairs
Underpinning near Portsmouth
For a no-obligation written quote on underpinning in Portsmouth, send photos of the cracking and any engineer’s report you already hold.