Mid Glamorgan · Wales
Underpinning in Mid Glamorgan
We carry out underpinning across Mid Glamorgan, from the larger towns to smaller places nearby. Parts of Mid Glamorgan have clay that can shrink near trees in dry spells. Every job starts with the cause, then the repair is specified to match it.
Guide price from£920per metre of wall inc VAT

- Area
- Mid Glamorgan
- Pricing region
- Wales
- Ground
- Clay in parts
- Towns listed
- 12
Is Mid Glamorgan prone to ground movement?
Mid Glamorgan lies on the South Wales coalfield, with dense historic workings, spoil tips and steep valley sides. Landslip, retaining walls and mining legacy are all live issues in the valleys.
Historic coal workings are recorded beneath parts of Mid Glamorgan, and a coal mining search is worth checking where movement is unexplained. Across Mid Glamorgan, most homes are long stone and brick terraces on valley sides, Victorian houses in Bridgend and post-war estates.
Is it time for underpinning? Common signs
- Floors sloping noticeably towards one external wall
- Movement continuing through more than one winter of monitoring
- One corner of the house visibly lower than the others
- A large tree nearby that cannot be removed or reduced
What should you budget for underpinning in Mid Glamorgan?
The ranges below reflect typical Wales 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 | £920 – £1,400 | per metre of wall |
| Beam-and-base underpinning | £1,400 – £2,300 | per metre of wall |
| Mini-piled underpinning | £1,850 – £3,200 | per metre of wall |
| Engineer's design and building control feesest. | £735 – £2,300 | per scheme |
Repair options we may recommend
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
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
What to expect when we carry out underpinning
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.
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.
Do you need approval for underpinning in Wales?
In Wales, the Welsh version of the Building Regulations applies. Underpinning and other work that alters or strengthens the structure needs building control approval and inspection; like-for-like repairs often do not. The Party Wall etc. Act 1996 applies to work on party walls and excavation close to a neighbour’s foundations.
Underpinning near you in Mid Glamorgan
- Rhondda
- Tonypandy
- Bridgend
- Merthyr Tydfil
- Pontypridd
- Aberdare
- Caerphilly
- Maesteg
- Porthcawl
- Llantrisant
- Nelson
- Mountain Ash
Your underpinning questions
Does the ground around Rhondda cause cracking?
Mid Glamorgan lies on the South Wales coalfield, with dense historic workings, spoil tips and steep valley sides. Landslip, retaining walls and mining legacy are all live issues in the valleys. Historic coal workings are recorded beneath parts of Mid Glamorgan, and a coal mining search is worth checking where movement is unexplained. Only an investigation on site can say why a particular building has moved.
How much will underpinning cost in Mid Glamorgan?
On Wales rates, underpinning starts from about £920 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.
Will underpinning affect selling my house?
It needs explaining to buyers, but a properly documented scheme is far better than unresolved movement. Keep the engineer’s design, the building control completion certificate and any insurance paperwork. Lenders and surveyors will usually ask for these before agreeing a sale.
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.