Flint · Clwyd
Underpinning in Flint
Before any underpinning goes ahead on a Flint property, building control has to approve the design and inspect the excavations. Where the wall is shared, party wall notices may be needed too in England and Wales, so allow time for paperwork before the dig.
Guide price from£920per metre of wall inc VAT

- Postcodes
- CH6
- Population
- about 26,000
- Area
- Clwyd
- Pricing region
- Wales
Is Clwyd prone to ground movement?
Flint, Clwyd: about 26,000 residents across postcode districts CH6. Neighbouring towns we cover: Connah's Quay (5 miles), Mold (5 miles) and Buckley (6 miles).
Clwyd has a mix of ground, with clay in some places and firmer rock in others. Parts of Clwyd lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. What you mostly find across Clwyd: brick colliery terraces, seaside villas in Rhyl and Colwyn Bay, and post-war estates.
What to look for before calling about underpinning
- Movement continuing through more than one winter of monitoring
- One corner of the house visibly lower than the others
- Floors sloping noticeably towards one external wall
Underpinning prices in Flint
Prices in Flint 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 |
How we usually approach underpinning
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
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 happens during underpinning, step by step?
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.
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.
Questions about underpinning in Flint
What is the price of underpinning in Flint?
Guide prices for underpinning in Flint 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 carry out underpinning in Flint?
Yes. We take enquiries from across Flint, including CH6, and from nearby places such as Connah's Quay and Mold. Send photos for a free initial view and we will tell you what happens next.
Does the ground around Flint cause cracking?
The North Wales coalfield runs beneath parts of Wrexham and Flintshire, where historic workings are recorded, while the coast and vale have glacial clays and the hills are older hard rock. Only an investigation can say why a particular building has moved.
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 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.
More repairs we carry out in Flint
- Retaining wall repairs
- Extension pulling away repairs
- Brick arch repairs
- Resin injection ground stabilisation
- Structural crack repairs
Underpinning near Flint
If your insurer has agreed underpinning for your Flint home, share the loss adjuster’s schedule and we will price the repair to it in writing.