Dorchester · Dorset
Bay window subsidence repairs in Dorchester
If your Dorchester 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
- DT1
- Population
- about 17,000
- Area
- Dorset
- Pricing region
- South West
Is Dorset prone to ground movement?
Dorchester, Dorset: about 17,000 residents across postcode districts DT1. Nearby places we cover include Weymouth (7 miles), Yeovil (18 miles) and Poole (20 miles).
Dorset has a mix of ground, with clay in some places and firmer rock in others. Ground movement here is more often linked to soils, drains and trees than to mining. Housing stock in Dorset: Stone and brick villages, Victorian villas in Bournemouth, and inter-war and post-war semis.
Symptoms that point to bay window subsidence repairs
- A vertical crack where the bay meets the front wall
- Bay roof or lead flashing pulling away from the main wall
- A step or slope in the bay floor towards the window
Guide prices for bay window subsidence repairs in Dorchester
For Dorchester we use South West 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 |
|---|---|---|
| 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
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
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
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.
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.
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.
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 will bay window subsidence repairs cost in Dorchester?
Guide prices for bay window subsidence repairs in Dorchester 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 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.
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.
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.
Is a crack between my bay and the house serious?
It is often not serious, especially if it is old, fine and unchanged for years. A crack that is widening, tapering or matched by sticking windows and a sloping bay floor needs looking at. An engineer’s inspection, sometimes with monitoring, will confirm whether the bay is still moving.
Other structural repairs in Dorchester
Bay window subsidence repairs near Dorchester
Call about the cracked bay at your Dorchester property; a free initial assessment comes first, with a fixed written price once the repair is specified.