Bromley · Greater London
Floor joist repairs in Bromley
If your floor in Bromley dips by a wall or bounces in the middle of the room, the joists are worth checking. Send photos of the floor, the outside wall at ground level and any air bricks, and we will tell you what the pattern suggests.
Guide price from£310per joist inc VAT

- Postcodes
- BR1, BR2, BR4, BR5, BR6
- Population
- about 330,000
- Area
- Greater London
- Pricing region
- London
What is the ground like in Greater London?
Bromley takes in postcode districts including BR1, BR2, BR4, BR5, BR6, with about 330,000 residents. Neighbouring towns we cover: Swanley (5 miles), Lewisham (5 miles) and Croydon (6 miles).
Shrinkable clay is widespread in Greater London. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
What should you budget for floor joist repairs in Bromley?
Prices in Bromley 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 |
Repair options we may recommend
Sistering a joist
A new length of treated timber, the same depth as the original, is bolted or screwed alongside the damaged joist so the two share the load. It is the quickest fix for a notched, cracked or sagging joist that is otherwise sound, usually after lifting a few boards.
Best for: Cut, cracked or sagging joists with sound ends
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 to expect when we carry out floor joist repairs
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.
Repair the structure
Boards are lifted and numbered if they are going back, and rotten timber is cut out. New treated timber is fixed and checked with a level before strutting, hangers and any restraint straps go in.
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.
Is it time for floor joist repairs? Common signs
- Floor bouncing, or ornaments rattling, when someone walks across
- A musty smell, or fungal strands showing between the boards
- Ceiling cracks below that follow the line of the joists
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.
Your floor joist repairs questions
How much should I budget for floor joist repairs in Bromley?
Guide prices for floor joist repairs in Bromley 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 Bromley?
Yes. We take enquiries from across Bromley, including BR1, BR2, BR4, BR5, and from nearby places such as Swanley and Lewisham. 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.
Is a sagging floor dangerous?
A gentle, long-standing sag is usually not dangerous, and many older floors have moved slightly over a century. A sag that is getting worse, soft boards or a floor dropping near a wall needs checking soon, because rotten joist ends can lose their bearing.
What causes rot in floor joists?
Damp causes almost all joist rot. Joist ends in damp walls, voids with blocked air bricks, leaking pipes and high outside ground levels keep timber wet enough for fungi to grow. Replacing timber without fixing the damp usually means the rot returns.
Related work in Bromley
- Structural surveys and crack monitoring
- Brick arch repairs
- Subsidence insurance claim repairs
- Concrete repairs
- Crack stitching
Floor joist repairs near Bromley
If a floor in Bromley has dropped after plumbing or heating work, send photos of any lifted boards and notches, and we will price the strengthening.