Monmouth · Gwent
Underpinning in Monmouth
If an engineer has recommended underpinning for your Monmouth 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
- NP25
- Population
- about 10,000
- Area
- Gwent
- Pricing region
- Wales
What is the ground like in Gwent?
Monmouth, Gwent: about 10,000 residents across postcode districts NP25. Nearby places we cover include Chepstow (12 miles), Abergavenny (13 miles) and Pontypool (16 miles).
Clay soils are found in parts of Gwent. Historic coal workings are recorded beneath parts of Gwent, and a coal mining search is worth checking where movement is unexplained. What you mostly find across Gwent: valley terraces on steep hillsides, Victorian houses in Newport and Abergavenny, and post-war estates.
Symptoms that point to underpinning
- Cracks that keep widening after the drains have been repaired
- Floors sloping noticeably towards one external wall
- A large tree nearby that cannot be removed or reduced
Guide prices for underpinning in Monmouth
Guide prices below are for homes in Monmouth, on Wales rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| 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
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
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.
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.
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 Monmouth?
Guide prices for underpinning in Monmouth 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 Monmouth?
Yes, Monmouth is covered, along with postcode districts NP25. We also cover nearby Chepstow and Abergavenny.
Is the ground in Gwent prone to subsidence?
The valleys of Blaenau Gwent, Torfaen and Islwyn lie on the South Wales coalfield with extensive historic workings and spoil tips, while Newport and Monmouthshire have Mercia Mudstone, alluvium and Old Red Sandstone. 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.
Do I need to tell my neighbours about underpinning?
In England and Wales you usually do. Underpinning a party wall normally needs two months’ notice, and excavating near a neighbour’s foundations needs one month’s notice under the Party Wall etc. Act 1996. Scotland and Northern Ireland have no equivalent Act, but agreeing the work in writing still helps.
Other structural repairs in Monmouth
- Gable end wall repairs
- Floor joist repairs
- Lintel replacement
- Bowing wall repairs
- Retaining wall repairs
Underpinning near Monmouth
Not sure your Monmouth home needs underpinning at all? Send photos for a free initial assessment and we will say whether an engineer should look first.