Salisbury · Wiltshire
Floor joist repairs in Salisbury
Houses in Salisbury 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
- SP1, SP2
- Population
- about 45,000
- Area
- Wiltshire
- Pricing region
- South West
What should you know about the ground under Salisbury?
Postcode districts SP1, SP2 cover Salisbury, a Wiltshire town of about 45,000 people. We also take enquiries from nearby Romsey (14 miles), Andover (16 miles) and Totton (17 miles).
Parts of Wiltshire have clay that can shrink near trees in dry spells. Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in Wiltshire: Stone cottages, railway terraces in Swindon, and large post-war and new-build estates.
Symptoms that point to floor joist repairs
- A musty smell, or fungal strands showing between the boards
- Floor bouncing, or ornaments rattling, when someone walks across
- Floor dipping towards an outside wall or in the middle of the room
Guide prices for floor joist repairs in Salisbury
Prices in Salisbury are worked out on South West 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 | £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 |
Methods for 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
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
From first photo to finished repair
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.
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.
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 Salisbury?
Guide prices for floor joist repairs in Salisbury 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 Salisbury?
Yes. We take enquiries from across Salisbury, including SP1, SP2, and from nearby places such as Romsey and Andover. Send photos for a free initial view and we will tell you what happens next.
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.
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.
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.
Other structural repairs in Salisbury
- Roof structure repairs
- Gable end wall repairs
- Lintel replacement
- Structural surveys and crack monitoring
- Retaining wall repairs
Floor joist repairs near Salisbury
For a guide price on floor joist repairs in Salisbury, use the quote tool or send photos of the dip, any soft boards and the air bricks.