Chichester · West Sussex
Floor joist repairs in Chichester
Houses in Chichester and across West Sussex with suspended timber ground floors rely on dry walls and a ventilated void to stay sound. When either fails, rot usually starts at the edges of the room long before anything shows in the middle.
Guide price from£280per joist inc VAT

- Postcodes
- PO19
- Population
- about 32,000
- Area
- West Sussex
- Pricing region
- South East
What should you know about the ground under Chichester?
Chichester is in West Sussex and takes in postcode districts PO19. About 32,000 people live there. We also take enquiries from nearby Bognor Regis (6 miles), Emsworth (7 miles) and Hayling Island (9 miles).
Shrinkable clay is widespread in West Sussex. Ground movement here is more often linked to soils, drains and trees than to mining. Across West Sussex, most homes are Wealden cottages, 1930s semis and bungalows on the coast, and new-town estates in Crawley.
Methods for 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
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
From first photo to finished repair
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.
Symptoms that point to floor joist repairs
- A gap opening up between the skirting board and the floor
- Soft or spongy boards near outside walls, hearths or the bathroom
- A musty smell, or fungal strands showing between the boards
Guide prices for floor joist repairs in Chichester
These are guide prices for Chichester, using South East rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.
| 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 |
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.
Frequently asked questions
How much will floor joist repairs cost in Chichester?
Guide prices for floor joist repairs in Chichester start from about £280 per joist, 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 cover Chichester?
We do. Chichester and the surrounding area are covered, including nearby Bognor Regis and Emsworth. A free initial assessment from your photos is the first step.
Is the ground in West Sussex prone to subsidence?
North West Sussex around Crawley and Horsham sits on Weald Clay, the South Downs are chalk, and the coastal plain has brickearth and gravels. The Weald Clay is prone to shrink-swell movement near 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.
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.
Other structural repairs in Chichester
- Structural surveys and crack monitoring
- Extension pulling away repairs
- Concrete repairs
- Resin injection ground stabilisation
- Gable end wall repairs
Floor joist repairs near Chichester
For a guide price on floor joist repairs in Chichester, use the quote tool or send photos of the dip, any soft boards and the air bricks.