Southwark · Greater London
Floor joist repairs in Southwark
Whether it is one soft patch by the bathroom or a whole room dropping towards the wall, floor joist repairs in Southwark 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
- SE1, SE5, SE8, SE11, SE14
- Population
- about 310,000
- Area
- Greater London
- Pricing region
- London
Why does the ground in Greater London matter for floor joist repairs?
Southwark takes in postcode districts including SE1, SE5, SE8, SE11, SE14, with about 310,000 residents. Nearby, we also cover Lambeth (2 miles), Lewisham (3 miles) and Tower Hamlets (4 miles).
Greater London is one of the parts of the UK where clay soils are most likely to move with the seasons. 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.
What happens during floor joist repairs, step by step?
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.
Written quote
You get a no-obligation written quote listing which joists are sistered, spliced or replaced and any sleeper wall or ventilation work. It becomes a fixed price in writing once the repair is specified.
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.
What to look for before calling about floor joist repairs
- Soft or spongy boards near outside walls, hearths or the bathroom
- Ceiling cracks below that follow the line of the joists
- A gap opening up between the skirting board and the floor
Floor joist repairs prices in Southwark
The ranges below reflect typical London costs for floor joist repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| 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
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
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
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 Southwark
How much should I budget for floor joist repairs in Southwark?
Guide prices for floor joist repairs in Southwark 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 Southwark?
Yes, Southwark is covered, along with postcode districts SE1, SE5, SE8, SE11. We also cover nearby Lambeth and Lewisham.
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.
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.
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.
Related work in Southwark
- Brick arch repairs
- Subsidence insurance claim repairs
- Structural surveys and crack monitoring
- Concrete repairs
- Bowing wall repairs
Floor joist repairs near Southwark
For a guide price on floor joist repairs in Southwark, use the quote tool or send photos of the dip, any soft boards and the air bricks.