Dorchester · Dorset
Extension pulling away repairs in Dorchester
For many Dorchester 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£620per junction inc VAT

- Postcodes
- DT1
- Population
- about 17,000
- Area
- Dorset
- Pricing region
- South West
What should you know about the ground under Dorchester?
Postcode districts DT1 cover Dorchester, a Dorset town of about 17,000 people. Neighbouring towns we cover: Weymouth (7 miles), Yeovil (18 miles) and Poole (20 miles).
Clay soils are found in parts of Dorset. Ground movement here is more often linked to soils, drains and trees than to mining. Across Dorset, most homes are stone and brick villages, Victorian villas in Bournemouth, and inter-war and post-war semis.
What happens during extension pulling away repairs, step by step?
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.
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.
What to look for before calling about extension pulling away repairs
- Mastic or render at the joint repeatedly splitting open
- A vertical crack or gap where the extension meets the house
- Extension roof flashing lifting off the original wall
Extension pulling away repairs prices in Dorchester
Prices in Dorchester are worked out on South 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. | £620 – £2,050 | per junction |
| Movement joint and making goodest. | £410 – £1,250 | per junction |
| Underpinning the extension where needed | £1,050 – £2,600 | per metre of wall |
How we usually approach 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
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
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.
Questions about extension pulling away repairs in Dorchester
How much should I budget for extension pulling away repairs in Dorchester?
Guide prices for extension pulling away repairs in Dorchester start from about £620 per junction, including VAT, on South 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 Dorchester?
Yes. We take enquiries from across Dorchester, including DT1, and from nearby places such as Weymouth and Yeovil. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Dorset crack?
Dorset mixes chalk downs, Oxford and Kimmeridge Clays in the vales, and the sands and gravels of the Poole basin. Clay vales can shrink and swell, and parts of the coast are known for landslip. Only an investigation can say why a particular building has moved.
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.
Who is responsible if a recent extension is moving?
If the extension is recent, the original builder, the designer or building control records may be relevant, and you may have rights against the builder. Gather the plans, completion certificate and contract. Insurance often excludes defects in new construction, so check your policy.
Related work in Dorchester
- Floor joist repairs
- Bowing wall repairs
- Bay window subsidence repairs
- Subsidence repairs
- Structural crack repairs
Extension pulling away repairs near Dorchester
Share the loss adjuster’s schedule for your Dorchester extension claim, and we will price the junction repair and making good to it in writing.