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County Antrim · Northern Ireland

Subsidence repairs in County Antrim

If you live in County Antrim and are looking at subsidence repairs, the first question is why the wall moved. Shrinkable clay is less common in County Antrim than in south-east England; historic brine and salt working has caused ground movement in parts of County Antrim in the past.

Guide price from£2,200per property inc VAT

Stepped subsidence crack running down from a window corner, with a tell-tale gauge fixed across it
Area
County Antrim
Pricing region
Northern Ireland
Ground
Mostly firmer ground
Towns listed
8

What should you know about the ground under 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. Housing stock in County Antrim: Red-brick terraces in Belfast, Victorian villas, and post-war and newer estates.

What happens during subsidence repairs, step by step?

  1. Send photos or call

    Send photos of the cracks with a coin or tape for scale, and say when you first noticed them. We give a free initial assessment and suggest whether an engineer, a drain survey or your insurer comes first.

  2. Written quote

    We price the agreed repair and confirm a fixed price in writing once it is specified. If there is an insurance claim, we can price to the loss adjuster’s or engineer’s schedule instead of our own scope.

  3. Repairs and making good

    Cracks are stitched and repointed outside, plaster is renewed along the crack lines inside, and sticking doors are eased. Where the work needs it, we deal with building control and hand over the paperwork.

What to look for before calling about subsidence repairs

  • Cracks that open in summer and partly close again in winter
  • Wallpaper rippling or tearing where the wall meets the ceiling
  • Fresh cracks showing on both the inside and outside of one wall
  • Diagonal cracks wider at the top, running from window or door corners

Subsidence repairs prices in County Antrim

These are guide prices for County Antrim, using Northern Ireland rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.

Guide prices inc VAT on Northern Ireland rates. Items marked est. are our estimates.
ItemGuide pricePer
Structural engineer's investigation and report£440 – £1,750per property
CCTV drain survey (common first check)£130 – £310per survey
Typical repair once the cause is dealt with: crack stitching and making goodest.£2,200 – £10,600per property
Foundation strengthening where it is needed (see underpinning)£880 – £3,100per metre of wall

How we usually approach subsidence repairs

Crack stitching and making good

Once movement has stopped, cracked brickwork is cut along the bed joints, stainless helical bars are bonded in to tie the wall together, and the joints are repointed to match. Inside, plaster is renewed along the crack line before redecoration.

Best for: Category 1 to 3 cracking in walls that are otherwise sound

Remove the cause, then repair

Most subsidence is dealt with this way. The drain is repaired or the vegetation managed, the house is watched to confirm it has stabilised, and then the cracks are stitched, repointed and made good inside. It is the least disruptive route and usually the cheapest.

Best for: Clay movement or drain leaks where the cause can be removed

Foundation strengthening

Where the ground cannot be made stable, the load is carried down to firmer soil by underpinning, a beam-and-base scheme, mini-piles or resin injection, depending on the soil and access. It is designed by an engineer and is the exception, not the rule.

Best for: Ongoing movement where removing the cause has not worked

Subsidence: stepped crack above a corner that has dropped on drying claySHRINKABLE CLAYSTEPPED CRACKROOTS DRAW MOISTURE FROM CLAYINDICATIVE · NOT TO SCALE
Subsidence: stepped crack above a corner that has dropped on drying clay. Indicative drawing, not to scale.

Do you need approval for subsidence repairs 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.

Find subsidence repairs in your County Antrim town

Questions about subsidence repairs in County Antrim

Why do houses in County Antrim crack?

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 subsidence repairs cost in County Antrim?

On Northern Ireland rates, subsidence repairs starts from about £2,200 per property, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.

Should I cut down the tree near my house?

Not without advice, because felling a mature tree on clay can make things worse. As the roots stop drawing water, the clay swells and can lift the foundations, which is called heave. Pruning or staged removal may be advised instead. Check whether the tree is protected.

How do I know if cracks are subsidence?

Subsidence cracks are usually tapered, run diagonally from door and window corners, and show on both faces of the wall. Fine vertical cracks in new plaster are more often shrinkage. An engineer’s inspection, sometimes with monitoring, is the reliable way to tell.

Does subsidence always need underpinning?

No, most subsidence is repaired without underpinning. When a leaking drain is fixed or nearby vegetation is managed, the ground usually stabilises and the house needs only crack repairs. Foundation work is kept for movement that continues after the cause has gone.

Related work in County Antrim

Next step

Send us photos of the crack or movement

A free initial assessment from your photos, then a no-obligation written quote. If an engineer, drain survey or monitoring is needed first, we say so before you spend anything.

CallGet a quote