East Sussex · England
Floor joist repairs in East Sussex
Looking for floor joist repairs in East Sussex? Send us photos for a free initial view. East Sussex is one of the parts of the UK where clay soils are most likely to move with the seasons, so we look at the ground, drains and nearby trees before recommending anything.
Guide price from£280per joist inc VAT

- Area
- East Sussex
- Pricing region
- South East
- Ground
- Shrinkable clay widespread
- Towns listed
- 10
Why does the ground in East Sussex matter for floor joist repairs?
Inland East Sussex is Weald Clay and Wealden sands, while the South Downs and the coast around Brighton and Eastbourne are chalk. The Weald Clay areas are prone to shrink-swell movement near trees.
Ground movement here is more often linked to soils, drains and trees than to mining. Housing stock in East Sussex: Regency and Victorian terraces on the coast, Wealden timber-framed houses, and inter-war bungalows and semis.
How we usually approach floor joist repairs
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
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
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 dipping towards an outside wall or in the middle of the room
- A gap opening up between the skirting board and the floor
- Ceiling cracks below that follow the line of the joists
- Soft or spongy boards near outside walls, hearths or the bathroom
Floor joist repairs prices in East Sussex
Prices in East Sussex are worked out on South East 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 | £280 – £450 | per joist |
| Whole room of joists and boards | £2,250 – £6,700 | per room |
| Sleeper wall rebuild and ventilationest. | £450 – £1,700 | per room |
Do you need approval 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.
Find floor joist repairs in your East Sussex town
Questions about floor joist repairs in East Sussex
Why do houses in East Sussex crack?
Inland East Sussex is Weald Clay and Wealden sands, while the South Downs and the coast around Brighton and Eastbourne are chalk. The Weald Clay areas are prone to shrink-swell movement near trees. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.
How much will floor joist repairs cost in East Sussex?
On South East rates, floor joist repairs starts from about £280 per joist, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
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.
Can floor joists be repaired without taking up the whole floor?
Yes, in most cases only the boards over the affected joists need lifting, and three or four boards are often enough to sister a joist or splice a rotten end. Widespread rot is the exception, because the whole floor must come up to remove the decay.
What is sistering a floor joist?
Sistering is fixing a new length of timber alongside an existing joist so the two share the load. It strengthens a notched, cracked or sagging joist without removing it, so it is quicker and less disruptive than replacement.