Horley · Surrey
Bay window subsidence repairs in Horley
A cracked bay in Horley can be anything from an old, stable joint to a foundation that is still dropping. Photos of the outside junction and the inside corners usually show which is more likely and whether an engineer should look.
Guide price from£670per bay inc VAT

- Postcodes
- RH6
- Population
- about 21,000
- Area
- Surrey
- Pricing region
- South East
What should you know about the ground under Horley?
Horley is in Surrey and takes in postcode districts RH6. About 21,000 people live there. If you are just outside Horley, we also cover Crawley (4 miles), Redhill (5 miles) and East Grinstead (7 miles).
Much of Surrey sits on clay that shrinks in dry summers and swells in wet winters. Ground movement here is more often linked to soils, drains and trees than to mining. Housing stock in Surrey: Victorian and Edwardian villas, 1930s semis and detached houses in the commuter towns, and post-war estates.
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.
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.
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 Horley
For Horley we use South East 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. | £670 – £2,000 | per bay |
| Traditional underpinning of a bay | £3,350 – £7,850 | per bay |
| Mini-piled bay underpinning | £5,600 – £13,400 | per bay |
Methods for 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
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
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
What is the price of bay window subsidence repairs in Horley?
Guide prices for bay window subsidence repairs in Horley start from about £670 per bay, including VAT, on South East rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you carry out bay window subsidence repairs in Horley?
Yes, Horley is covered, along with postcode districts RH6. We also cover nearby Crawley and Redhill.
Does the ground around Horley cause cracking?
North Surrey sits on London Clay, the south on Weald Clay, with chalk along the North Downs and sands in the west. Large gardens with mature trees on clay make seasonal subsidence a familiar problem. Only an investigation can say why a particular building has moved.
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.
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.
More repairs we carry out in Horley
- Roof structure repairs
- Gable end wall repairs
- Floor joist repairs
- Chimney stack repairs
- Subsidence repairs
Bay window subsidence repairs near Horley
Photos of the bay floor, window and junction crack are enough to start; send them about your Horley home and we will reply with a view.