Bournemouth · Dorset
Bay window subsidence repairs in Bournemouth
If your Bournemouth bay window has started sticking and a gap has opened at the junction, it is worth finding out whether the bay is still moving. A stable crack needs a straightforward tie-in, whereas an active one may need a new foundation.
Guide price from£620per bay inc VAT
- Postcodes
- BH1, BH2, BH4
- Population
- about 160,000
- Area
- Dorset
- Pricing region
- South West
What is the ground like in Dorset?
Postcode districts BH1, BH2, BH4 cover Bournemouth, a Dorset town of about 160,000 people. If you are just outside Bournemouth, we also cover Christchurch (4 miles), Poole (5 miles) and Ferndown (6 miles).
Clay soils are found in parts of Dorset. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Dorset: stone and brick villages, Victorian villas in Bournemouth, and inter-war and post-war semis.
How we usually approach bay window subsidence repairs
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
Mini-piled bay underpinning
Small piles are installed to depth around or beneath the bay and linked by a reinforced beam or needles that pick up its weight. It suits deeper soft ground and heavy root activity, and the compact rigs fit into a front garden.
Best for: Deep clay, nearby trees, or poor ground below the bay
What happens during bay window subsidence repairs, step by step?
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.
Agree the repair
The engineer decides between tie-in repairs and underpinning. We confirm a fixed price in writing once the repair is specified, including scaffolding if needed, the bay window, roof flashing and internal making good.
Carry out the work
Ties are fitted across the junction, or the bay is underpinned in sequence with building control inspecting the dig. The bay window and flashings are checked and eased or resealed where the movement has disturbed them.
What to look for before calling about bay window subsidence repairs
- Gaps opening around the internal bay window board
- Bay window sash or casement sticking or binding
- A step or slope in the bay floor towards the window
Bay window subsidence repairs prices in Bournemouth
Guide prices below are for homes in Bournemouth, on South West rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| 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 |
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.
Questions about bay window subsidence repairs in Bournemouth
How much will bay window subsidence repairs cost in Bournemouth?
Guide prices for bay window subsidence repairs in Bournemouth 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.
Do you cover Bournemouth?
Yes. We take enquiries from across Bournemouth, including BH1, BH2, BH4, and from nearby places such as Christchurch and Poole. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Dorset prone to subsidence?
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 bay be underpinned without underpinning the house?
Yes, underpinning only the bay is common because it is usually the part on shallower footings. The engineer designs the junction so the strengthened bay and the existing house can move slightly without cracking, sometimes with a movement joint or ties.
Why do bay windows crack away from the house?
Bays often stand on shallower footings than the main walls, so they react to drying clay, roots and drain leaks that the deeper house foundations escape. Many bays were also never properly tied in, so any movement opens a clean vertical crack at the junction.
Other structural repairs in Bournemouth
- Resin injection ground stabilisation
- Extension pulling away repairs
- Lintel replacement
- Structural crack repairs
- Retaining wall repairs
Bay window subsidence repairs near Bournemouth
Call about the cracked bay at your Bournemouth property; a free initial assessment comes first, with a fixed written price once the repair is specified.