County Down · Northern Ireland
Extension pulling away repairs in County Down
We arrange surveys and price extension pulling away repairs throughout County Down. Clay shrinkage is less of a concern in County Down, so other causes such as drains, poor footings or older walls are checked first, and we take that into account before recommending a method.
Guide price from£530per junction inc VAT

- Area
- County Down
- Pricing region
- Northern Ireland
- Ground
- Mostly firmer ground
- Towns listed
- 6
How do local ground conditions affect extension pulling away repairs in County Down?
County Down is mostly drumlin till over older rock and granite in the Mournes, with soft estuarine ground around Belfast Lough and Strangford.
Ground movement here is more often linked to soils, drains and trees than to mining. Across County Down, most homes are Victorian seaside houses in Bangor and Holywood, brick terraces and post-war estates.
Methods for extension pulling away repairs
Movement joint and making good
Where some seasonal movement is expected to continue, the junction is formed into a proper flexible movement joint with a compressible filler and sealant, so the two parts can move without cracking. Flashings and internal finishes are detailed to suit.
Best for: Minor ongoing movement that does not threaten the structure
Underpinning the extension
If the extension is still dropping because its footings are too shallow or on poor ground, they are taken deeper by mass concrete, beam-and-base or mini-piles. The engineer designs the scheme, and the junction is repaired once the new foundation is in.
Best for: Active movement from shallow footings, roots or soft ground
Junction crack repair with stainless ties
The open joint is cut out, stainless ties or helical bars are fixed across it into both the old and new masonry, and the joint is repointed or rendered to match. Inside, the corner is replastered. This suits extensions that moved once and have since stopped.
Best for: Settled extensions with a stable gap at the junction
From first photo to finished repair
Show us the junction
Send photos of the crack outside, the internal corner and any flashing above, with a measure for scale. We give a free initial assessment and an initial view on whether the gap is likely old or still opening.
Find what is moving
An independent chartered structural engineer can inspect, and we can arrange one. A drain survey under the extension, a trial pit at its footing and tell-tale monitoring across the joint are common checks before choosing the repair.
Choose the fix
The engineer decides between ties, a movement joint or underpinning. We confirm a fixed price in writing once the repair is specified, covering the junction, flashings, internal finishes and any foundation work.
Symptoms that point to extension pulling away repairs
- Extension roof flashing lifting off the original wall
- Mastic or render at the joint repeatedly splitting open
- Floor level dropping where the extension and house floors meet
- A vertical crack or gap where the extension meets the house
Guide prices for extension pulling away repairs in County Down
These are guide prices for County Down, using Northern Ireland rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.
| Item | Guide price | Per |
|---|---|---|
| Junction crack repair with stainless tiesest. | £530 – £1,750 | per junction |
| Movement joint and making goodest. | £350 – £1,050 | per junction |
| Underpinning the extension where needed | £880 – £2,200 | per metre of wall |
Do you need approval for extension pulling away 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.
Extension pulling away repairs near you in County Down
Frequently asked questions
Does the ground around Bangor cause cracking?
County Down is mostly drumlin till over older rock and granite in the Mournes, with soft estuarine ground around Belfast Lough and Strangford. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.
How much will extension pulling away repairs cost in County Down?
On Northern Ireland rates, extension pulling away repairs starts from about £530 per junction, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Can a drain under my extension cause it to move?
Yes, a cracked or displaced drain beneath or beside an extension can soften clay or wash away fine soil. A CCTV drain survey usually finds it. Repairing the drain is often the first and most important step before any repair to the walls.
Can I just fill the gap with mastic?
Mastic can keep water out short term, but it does not stop movement or reconnect the walls. If the gap reopens after filling, something is still moving. Photograph and measure it over a few months first, so an engineer can see the trend.
Is it normal for an extension to crack at the join?
A fine crack at the junction is fairly common, especially in the first few years as a new extension settles. It becomes a concern when the gap is widening, tapering, letting in water or matched by sticking doors and sloping floors. Those signs point to continuing movement.