Preston · Lancashire
Extension pulling away repairs in Preston
For many Preston homes, the extension was added decades after the house was built, on concrete that never matched the original footings. Where that difference causes movement, a designed movement joint or a deeper foundation is the usual fix.
Guide price from£575per junction inc VAT

- Postcodes
- PR1, PR2
- Population
- about 310,000
- Area
- Lancashire
- Pricing region
- North West
Why does the ground in Lancashire matter for extension pulling away repairs?
Preston, Lancashire: about 310,000 residents across postcode districts PR1, PR2. Nearby, we also cover Leyland (5 miles), Chorley (9 miles) and Blackburn (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.
Symptoms that point to extension pulling away repairs
- A vertical crack or gap where the extension meets the house
- Patio doors or windows in the extension starting to bind
- Mastic or render at the joint repeatedly splitting open
Guide prices for extension pulling away repairs in Preston
These are guide prices for Preston, using North West 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. | £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 |
Methods for extension pulling away repairs
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
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
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.
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.
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.
Frequently asked questions
How much should I budget for extension pulling away repairs in Preston?
Guide prices for extension pulling away repairs in Preston 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.
Can you survey a property in Preston?
We do. Preston and the surrounding area are covered, including nearby Leyland and Chorley. A free initial assessment from your photos is the first step.
Why do houses in Lancashire crack?
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.
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.
Will my extension need underpinning?
Often not. Many separating extensions are fixed by repairing a drain, tying the junction or forming a movement joint. Underpinning is for extensions that keep dropping because their footings are too shallow or the ground beneath is poor, as shown by monitoring.
Related work in Preston
Extension pulling away repairs near Preston
Send photos of the extension junction at your Preston home, inside and out, and we will give a free initial assessment and a guide price.