Blackburn · Lancashire
Extension pulling away repairs in Blackburn
Repairing a separating extension in Blackburn can be as simple as tying the junction or as involved as underpinning. The choice rests on the movement history and the ground, and we confirm a fixed written price once the repair is specified.
Guide price from£575per junction inc VAT

- Postcodes
- BB1, BB2
- Population
- about 150,000
- Area
- Lancashire
- Pricing region
- North West
What is the ground like in Lancashire?
Postcode districts BB1, BB2 cover Blackburn, a Lancashire town of about 150,000 people. We also take enquiries from nearby Darwen (4 miles), Accrington (5 miles) and Chorley (9 miles).
Parts of Lancashire have clay that can shrink near trees in dry spells. Parts of Lancashire lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. What you mostly find across Lancashire: stone and brick mill terraces, seaside villas in Blackpool and Lytham, and inter-war and post-war semis.
Is it time for extension pulling away repairs? Common signs
- A vertical crack or gap where the extension meets the house
- Patio doors or windows in the extension starting to bind
- Daylight or draughts showing through the internal corner joint
What should you budget for extension pulling away repairs in Blackburn?
Prices in Blackburn are worked out on North West 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 |
|---|---|---|
| Junction crack repair with stainless tiesest. | £575 – £1,900 | per junction |
| Movement joint and making goodest. | £385 – £1,150 | per junction |
| Underpinning the extension where needed | £960 – £2,400 | per metre of wall |
Repair options we may recommend
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
What to expect when we carry out extension pulling away repairs
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.
Repair the junction
Drains are repaired first if they are leaking. The joint is then tied, formed as a movement joint or rebuilt after underpinning, with roof flashings reset so the junction stays watertight. Building control is handled where needed.
Finish and hand over
Internal corners are replastered, skirtings and coving refixed, and doors or windows in the extension eased where the movement affected them. Records of the repair and any approvals are passed to you.
Rules for extension pulling away repairs in England
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Your extension pulling away repairs questions
What is the price of extension pulling away repairs in Blackburn?
Guide prices for extension pulling away repairs in Blackburn start from about £575 per junction, including VAT, on North West rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you carry out extension pulling away repairs in Blackburn?
Yes. We take enquiries from across Blackburn, including BB1, BB2, and from nearby places such as Darwen and Accrington. Send photos for a free initial view and we will tell you what happens next.
Does the ground around Blackburn cause cracking?
Lancashire is mostly glacial till over sandstone and mudstone, with the Burnley and Accrington coalfield in the east and soft coastal and estuarine ground on the Fylde. Old mill and mine sites leave made ground in many towns. Only an investigation can say why a particular building has moved.
What is a movement joint?
A movement joint is a deliberate, flexible break in a wall that lets two parts of a building move slightly without cracking. It is filled with a compressible material and sealed. At an extension junction it can replace a rigid joint that keeps cracking.
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.
More repairs we carry out in Blackburn
Extension pulling away repairs near Blackburn
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Blackburn home and we will reply with a view.