Christchurch · Dorset
Bay window subsidence repairs in Christchurch
Many bays in Christchurch were butted against the house rather than bonded into it with ties or toothed brickwork. That makes the junction the first place any differential movement shows, even when the bay foundation is reasonably sound.
Guide price from£620per bay inc VAT
- Postcodes
- BH6, BH7, BH23
- Population
- about 31,000
- Area
- Dorset
- Pricing region
- South West
Why does the ground in Dorset matter for bay window subsidence repairs?
Christchurch, Dorset: about 31,000 residents across postcode districts BH6, BH7, BH23. We also take enquiries from nearby Bournemouth (4 miles), New Milton (5 miles) and Ferndown (7 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.
From first photo to finished repair
Photos and first view
Send photos of the outside junction, the inside corners and the window, with a scale. We give a free initial assessment and tell you whether the crack looks old and stable or whether an engineer should inspect first.
Engineer and checks
Where the cause is unclear, an independent chartered structural engineer inspects, sometimes with a trial pit at the bay and a drain survey. We can arrange the engineer. Monitoring may be suggested if the movement could be seasonal.
Make good inside
Plaster around the bay and along the junction is renewed, the window board is refixed and the room is ready for decoration. Building control paperwork, where it applies, is passed to you for your records.
Symptoms that point to bay window subsidence repairs
- Gaps opening around the internal bay window board
- Bay window sash or casement sticking or binding
- A vertical crack where the bay meets the front wall
Guide prices for bay window subsidence repairs in Christchurch
The ranges below reflect typical South West costs for bay window subsidence repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| Item | Guide price | Per |
|---|---|---|
| Bay junction crack repair and tie-inest. | £620 – £1,850 | per bay |
| Traditional underpinning of a bay | £3,100 – £7,200 | per bay |
| Mini-piled bay underpinning | £5,150 – £12,400 | per bay |
Methods for bay window subsidence repairs
Traditional underpinning of the bay
The bay footing is excavated in short sections and new mass concrete is placed down to firmer ground below the zone affected by roots and seasons. Because a bay is a short length of wall, the work is compact, but it needs building control approval.
Best for: Active bay movement on firm ground at moderate depth
Junction crack repair and tie-in
Where movement has stopped, the open joint between bay and house is raked out, stainless ties or helical bars are fixed across it, and the joint is repointed to match. Internal plaster along the crack is cut back and renewed before redecoration.
Best for: Old, stable cracks where the bay is no longer moving
Rules for bay window subsidence 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 bay window subsidence repairs in Christchurch?
Guide prices for bay window subsidence repairs in Christchurch start from about £620 per bay, 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 Christchurch?
Yes, Christchurch is covered, along with postcode districts BH6, BH7, BH23. We also cover nearby Bournemouth and New Milton.
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.
How long does bay underpinning take?
Traditional underpinning of a bay usually takes about a week on site, and mini-piling a little longer depending on depth. A junction tie-in without underpinning normally takes one to two days. Approvals and any monitoring beforehand add to the overall timeline.
Can I just fill the crack myself?
Filling it hides the evidence without dealing with the cause, and if the bay is still moving the crack will reopen. Photograph it with a scale and date first. If you plan to claim on insurance, tell your insurer before any repair, including filling.
Related work in Christchurch
- Floor joist repairs
- Bowing wall repairs
- Boundary and garden wall repairs
- Subsidence repairs
- Subsidence insurance claim repairs
Bay window subsidence repairs near Christchurch
Photos of the bay floor, window and junction crack are enough to start; send them about your Christchurch home and we will reply with a view.