Westminster · Greater London
Floor joist repairs in Westminster
Whether it is one soft patch by the bathroom or a whole room dropping towards the wall, floor joist repairs in Westminster are priced only after the timber has been seen. Rot, notches and failed supports each need a different fix, and the quote says which.
Guide price from£310per joist inc VAT

- Postcodes
- EC1N, EC4, EC4A, EC4M, EC4N
- Population
- about 200,000
- Area
- Greater London
- Pricing region
- London
Why does the ground in Greater London matter for floor joist repairs?
We cover the whole of Westminster, including postcode districts EC1N, EC4, EC4A, EC4M, EC4N; about 200,000 people live in the borough. Neighbouring towns we cover: Kensington and Chelsea (2 miles), Camden (3 miles) and Islington (3 miles).
Much of Greater London 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. Typical buildings in Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
Floor joist repairs prices in Westminster
Prices in Westminster are worked out on London rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.
| Item | Guide price | Per |
|---|---|---|
| Splicing or sistering a damaged joist | £310 – £500 | per joist |
| Whole room of joists and boards | £2,500 – £7,500 | per room |
| Sleeper wall rebuild and ventilationest. | £500 – £1,900 | per room |
How we usually approach floor joist repairs
Replacing joists and boards
When rot or woodworm runs through most of a floor, it is usually cheaper to replace the joists, strutting and boards together. Where joists run parallel to an outside wall, restraint straps tie the new floor back to it so the wall keeps its lateral support.
Best for: Widespread rot, or a whole floor that has dropped
Splicing ends and fitting hangers
Where only the end has rotted, it is cut back to sound timber and a new piece is fixed alongside, bearing on the wall or on a new joist hanger. Missing or under-nailed hangers elsewhere are replaced at the same time. The damp in the wall must be fixed too.
Best for: Rotten joist ends in damp solid walls
What happens during floor joist repairs, step by step?
Photos and a call
Send photos of the dip or soft area, the outside wall at ground level and any air bricks. A short call about when it started, and any recent plumbing or heating work, tells us whether the problem is local or widespread.
Lift boards and inspect
On site we lift a few boards where the floor is worst and check the joist ends, sleeper walls and void with a moisture meter. Outside, we look for high ground, blocked vents and leaks keeping the timber wet.
Relay and ventilate
Boards are relaid or replaced, skirting refitted and air bricks cleared or added outside. We point out anything that would let damp back in, such as soil heaped against the wall, so the repair lasts.
What to look for before calling about floor joist repairs
- Floor bouncing, or ornaments rattling, when someone walks across
- Ceiling cracks below that follow the line of the joists
- Floor dipping towards an outside wall or in the middle of the room
Rules for floor joist repairs in England
Like-for-like repairs such as crack stitching and repointing do not usually need building control approval in England, but anything that changes or strengthens the structure, such as underpinning or rebuilding a wall, does. If the work touches a party wall, the Party Wall etc. Act 1996 may apply.
Questions about floor joist repairs in Westminster
How much should I budget for floor joist repairs in Westminster?
Guide prices for floor joist repairs in Westminster start from about £310 per joist, including VAT, on London 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 Westminster?
Yes. We take enquiries from across Westminster, including EC1N, EC4, EC4A, EC4M, and from nearby places such as Kensington and Chelsea and Camden. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Greater London crack?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees. Only an investigation can say why a particular building has moved.
Will my insurance pay for rotten floor joists?
Usually not, because rot, woodworm and gradual wear are standard exclusions. Damage from a sudden escape of water, or a floor that dropped through subsidence, may be treated differently. Check your policy, and tell your insurer before permanent repairs start if either applies.
Do I need building control for floor joist repairs?
Usually not for like-for-like repairs to a few joists, but replacing a whole floor structure can be building work. In Scotland that generally needs a building warrant, and in Northern Ireland council building control applies. We deal with building control where the work needs it.
Related work in Westminster
- Roof structure repairs
- Bay window subsidence repairs
- Gable end wall repairs
- Extension pulling away repairs
- Structural crack repairs
Floor joist repairs near Westminster
Got a bouncy or sinking floor in Westminster? Send a short video of someone walking across it, and we will tell you what it is likely to need.