Hampshire · England
Floor joist repairs in Hampshire
Hampshire has its own mix of ground and building types, and that shapes how floor joist repairs is done here. Shrinkable clay is widespread in Hampshire.
Guide price from£280per joist inc VAT
- Area
- Hampshire
- Pricing region
- South East
- Ground
- Shrinkable clay widespread
- Towns listed
- 22
What is the ground like in Hampshire?
Central Hampshire is chalk, while the south around Portsmouth, Southampton and the New Forest fringe and the north-east around Farnborough sit on London Clay, Reading Beds and other clays and sands. The clay areas see seasonal movement near trees.
Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in Hampshire: Victorian terraces in Portsmouth and Southampton, 1930s semis, and large post-war and new-build estates.
Guide prices for floor joist repairs in Hampshire
These are guide prices for Hampshire, 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 |
Methods for floor joist repairs
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
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
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
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.
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.
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.
Symptoms that point to floor joist repairs
- Ceiling cracks below that follow the line of the joists
- Floor bouncing, or ornaments rattling, when someone walks across
- A musty smell, or fungal strands showing between the boards
- Soft or spongy boards near outside walls, hearths or the bathroom
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.
Towns in Hampshire we cover for floor joist repairs
- Southampton
- Portsmouth
- Basingstoke
- Waterlooville
- Farnborough
- Eastleigh
- Winchester
- Havant
- Andover
- Fareham
- Aldershot
- Fleet
- Totton
- New Milton
- Bordon
- Hythe
- Alton
- Emsworth
- Hedge End
- Romsey
- Hayling Island
- Tadley
Frequently asked questions
Is the ground in Hampshire prone to subsidence?
Central Hampshire is chalk, while the south around Portsmouth, Southampton and the New Forest fringe and the north-east around Farnborough sit on London Clay, Reading Beds and other clays and sands. The clay areas see seasonal 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 Hampshire?
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.
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.
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.