Caerphilly · Mid Glamorgan
Underpinning in Caerphilly
If an engineer has recommended underpinning for your Caerphilly home, we can price the scheme from their drawings and calculations. You receive a fixed price in writing that covers the method, the length of wall, access and the making good afterwards.
Guide price from£920per metre of wall inc VAT

- Postcodes
- CF83
- Population
- about 31,000
- Area
- Mid Glamorgan
- Pricing region
- Wales
What should you know about the ground under Caerphilly?
Postcode districts CF83 cover Caerphilly, a Mid Glamorgan town of about 31,000 people. Nearby, we also cover Risca (6 miles), Pontypridd (6 miles) and Nelson (6 miles).
Parts of Mid Glamorgan have clay that can shrink near trees in dry spells. Historic coal workings are recorded beneath parts of Mid Glamorgan, and a coal mining search is worth checking where movement is unexplained. Housing stock in Mid Glamorgan: Long stone and brick terraces on valley sides, Victorian houses in Bridgend and post-war estates.
From first photo to finished repair
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.
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.
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.
Symptoms that point to underpinning
- Footings found to be very shallow during a trial pit
- Floors sloping noticeably towards one external wall
- Movement continuing through more than one winter of monitoring
Guide prices for underpinning in Caerphilly
Prices in Caerphilly are worked out on Wales 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 | £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 |
Methods for underpinning
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
Rules 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.
Frequently asked questions
How much will underpinning cost in Caerphilly?
Guide prices for underpinning in Caerphilly start from about £920 per metre of wall, including VAT, on Wales rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Caerphilly?
Yes, Caerphilly is covered, along with postcode districts CF83. We also cover nearby Risca and Pontypridd.
Is the ground in Mid Glamorgan prone to subsidence?
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. Only an investigation can say why a particular building has moved.
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.
Which underpinning method is best?
The right method depends on how deep firm ground lies, the load on the wall and the access. Mass concrete suits moderate depths, beam-and-base spreads heavier loads, and mini-piles reach deep soft ground or work through tight access. The engineer chooses the method from the site investigation.
Other structural repairs in Caerphilly
- Boundary and garden wall repairs
- Bay window subsidence repairs
- Subsidence insurance claim repairs
- Roof structure repairs
- Mining subsidence repairs
Underpinning near Caerphilly
Start with photos and a short description of the movement at your Caerphilly property; we will reply with a free initial assessment and the next step.