County Antrim · Northern Ireland
Underpinning in County Antrim
We arrange surveys and price underpinning throughout County Antrim. Most of County Antrim is on firmer ground than the clay belts of the south-east, and we take that into account before recommending a method.
Guide price from£880per metre of wall inc VAT
- Area
- County Antrim
- Pricing region
- Northern Ireland
- Ground
- Mostly firmer ground
- Towns listed
- 8
What is the ground like in County Antrim?
County Antrim is largely basalt over chalk, with soft estuarine 'sleech' along Belfast Lough that is notorious for settlement. Historic salt mining is recorded near Carrickfergus.
Historic brine and salt working has caused ground movement in parts of County Antrim in the past. What you mostly find across County Antrim: red-brick terraces in Belfast, Victorian villas, and post-war and newer estates.
Symptoms that point to underpinning
- Footings found to be very shallow during a trial pit
- One corner of the house visibly lower than the others
- Movement continuing through more than one winter of monitoring
- Cracks that keep widening after the drains have been repaired
Guide prices for underpinning in County Antrim
The ranges below reflect typical Northern Ireland 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 | £880 – £1,300 | per metre of wall |
| Beam-and-base underpinning | £1,300 – £2,200 | per metre of wall |
| Mini-piled underpinning | £1,750 – £3,100 | per metre of wall |
| Engineer's design and building control feesest. | £705 – £2,200 | 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
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
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.
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 Northern Ireland?
In Northern Ireland, the Building Regulations (Northern Ireland) 2012 apply and the council’s building control service approves structural work such as underpinning; minor like-for-like repairs usually need no approval. The Party Wall Act does not apply in Northern Ireland, so work to shared walls depends on deeds and agreement with neighbours.
Underpinning near you in County Antrim
Frequently asked questions
Does the ground around Belfast cause cracking?
County Antrim is largely basalt over chalk, with soft estuarine 'sleech' along Belfast Lough that is notorious for settlement. Historic salt mining is recorded near Carrickfergus. Historic brine and salt working has caused ground movement in parts of County Antrim in the past. Only an investigation on site can say why a particular building has moved.
How much will underpinning cost in County Antrim?
On Northern Ireland rates, underpinning starts from about £880 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.
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.
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.