Trowbridge · Wiltshire
Floor joist repairs in Trowbridge
Houses in Trowbridge and across Wiltshire 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£260per joist inc VAT

- Postcodes
- BA14
- Population
- about 41,000
- Area
- Wiltshire
- Pricing region
- South West
What should you know about the ground under Trowbridge?
We cover Trowbridge and its postcode districts BA14, part of Wiltshire, with a population of roughly 41,000. We also take enquiries from nearby Westbury (4 miles), Melksham (5 miles) and Bath (8 miles).
Clay soils are found in parts of Wiltshire. Ground movement here is more often linked to soils, drains and trees than to mining. Across Wiltshire, most homes are stone cottages, railway terraces in Swindon, and large post-war and new-build estates.
Floor joist repairs prices in Trowbridge
The ranges below reflect typical South West 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 | £260 – £410 | per joist |
| Whole room of joists and boards | £2,050 – £6,200 | per room |
| Sleeper wall rebuild and ventilationest. | £410 – £1,550 | per room |
How we usually approach floor joist repairs
Sleeper walls and ventilation
Settled or damp sleeper walls are rebuilt on a sound base with a damp-proof course under new timber plates. Blocked air bricks are cleared, extra ones added where the void has dead spots, and soil or paving heaped against the outside wall is lowered.
Best for: Damp ground floor voids or joists on poor supports
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.
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.
What to look for before calling about floor joist repairs
- A musty smell, or fungal strands showing between the boards
- Soft or spongy boards near outside walls, hearths or the bathroom
- Floor bouncing, or ornaments rattling, when someone walks across
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 Trowbridge
How much will floor joist repairs cost in Trowbridge?
Guide prices for floor joist repairs in Trowbridge start from about £260 per joist, including VAT, on South West rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Trowbridge?
Yes, Trowbridge is covered, along with postcode districts BA14. We also cover nearby Westbury and Melksham.
Is the ground in Wiltshire prone to subsidence?
Southern Wiltshire is chalk, while the north around Swindon, Chippenham and Trowbridge sits on Oxford and Kimmeridge Clays that are prone to seasonal movement near trees. Bath stone was mined underground around Corsham. 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.
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.
Other structural repairs in Trowbridge
- Chimney stack repairs
- Structural crack repairs
- Boundary and garden wall repairs
- Subsidence insurance claim repairs
- Wall tie replacement
Floor joist repairs near Trowbridge
For a guide price on floor joist repairs in Trowbridge, use the quote tool or send photos of the dip, any soft boards and the air bricks.