Colwyn Bay · Clwyd
Extension pulling away repairs in Colwyn Bay
If the corner joint in your Colwyn Bay extension keeps splitting after you fill it, something is still moving. Measuring the gap over a few months, with dated photos, gives an engineer the evidence to recommend the right repair.
Guide price from£550per junction inc VAT

- Postcodes
- LL28, LL29
- Population
- about 29,000
- Area
- Clwyd
- Pricing region
- Wales
What is the ground like in Clwyd?
With roughly 29,000 people, Colwyn Bay spans postcode districts LL28, LL29 in Clwyd. If you are just outside Colwyn Bay, we also cover Llandudno (5 miles), Abergele (6 miles) and Rhyl (10 miles).
Clwyd has a mix of ground, with clay in some places and firmer rock in others. Parts of Clwyd lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. What you mostly find across Clwyd: brick colliery terraces, seaside villas in Rhyl and Colwyn Bay, and post-war estates.
From first photo to finished repair
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.
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.
Symptoms that point to extension pulling away repairs
- Extension roof flashing lifting off the original wall
- Floor level dropping where the extension and house floors meet
- Patio doors or windows in the extension starting to bind
Guide prices for extension pulling away repairs in Colwyn Bay
For Colwyn Bay we use Wales rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| Item | Guide price | Per |
|---|---|---|
| Junction crack repair with stainless tiesest. | £550 – £1,850 | per junction |
| Movement joint and making goodest. | £370 – £1,100 | per junction |
| Underpinning the extension where needed | £920 – £2,300 | per metre of wall |
Methods for extension pulling away repairs
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
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
Rules for extension pulling away repairs in Wales
In Wales, the Welsh version of the Building Regulations applies. Underpinning and other work that alters or strengthens the structure needs building control approval and inspection; like-for-like repairs often do not. The Party Wall etc. Act 1996 applies to work on party walls and excavation close to a neighbour’s foundations.
Frequently asked questions
How much will extension pulling away repairs cost in Colwyn Bay?
Guide prices for extension pulling away repairs in Colwyn Bay start from about £550 per junction, including VAT, on Wales rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Colwyn Bay?
We do. Colwyn Bay and the surrounding area are covered, including nearby Llandudno and Abergele. A free initial assessment from your photos is the first step.
Is the ground in Clwyd prone to subsidence?
The North Wales coalfield runs beneath parts of Wrexham and Flintshire, where historic workings are recorded, while the coast and vale have glacial clays and the hills are older hard rock. 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.
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.
Other structural repairs in Colwyn Bay
- Subsidence insurance claim repairs
- Crack stitching
- Boundary and garden wall repairs
- Concrete repairs
- Underpinning
Extension pulling away repairs near Colwyn Bay
For a no-obligation written quote to repair an extension pulling away in Colwyn Bay, call or send a few photos with a tape measure across the gap.