Portsmouth · Hampshire
Floor joist repairs in Portsmouth
If your floor in Portsmouth dips by a wall or bounces in the middle of the room, the joists are worth checking. Send photos of the floor, the outside wall at ground level and any air bricks, and we will tell you what the pattern suggests.
Guide price from£280per joist inc VAT

- Postcodes
- PO1, PO2, PO5
- Population
- about 210,000
- Area
- Hampshire
- Pricing region
- South East
How do local ground conditions affect floor joist repairs in Portsmouth?
Portsmouth, Hampshire: about 210,000 residents across postcode districts PO1, PO2, PO5. Nearby, we also cover Fareham (5 miles), Hayling Island (5 miles) and Havant (6 miles).
Hampshire is one of the parts of the UK where clay soils are most likely to move with the seasons. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Hampshire: Victorian terraces in Portsmouth and Southampton, 1930s semis, and large post-war and new-build estates.
How much will floor joist repairs cost in Portsmouth?
Guide prices below are for homes in Portsmouth, on South East rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| 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 |
Which repair method suits a home in Portsmouth?
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 when we carry out floor joist repairs in Portsmouth?
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.
Signs you may need floor joist repairs
- A musty smell, or fungal strands showing between the boards
- Ceiling cracks below that follow the line of the joists
- Floor dipping towards an outside wall or in the middle of the 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.
Floor joist repairs in Portsmouth: questions and answers
How much should I budget for floor joist repairs in Portsmouth?
Guide prices for floor joist repairs in Portsmouth 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.
Can you survey a property in Portsmouth?
We do. Portsmouth and the surrounding area are covered, including nearby Fareham and Hayling Island. A free initial assessment from your photos is the first step.
Why do houses in Hampshire crack?
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. Only an investigation can say why a particular building has moved.
Why is my floor bouncy?
A bouncy floor usually means the joists are deflecting too much, often because they span too far, have lost their strutting or have been weakened by notches. It rarely means imminent failure, but it is worth checking, especially if the bounce appeared after work in the room.
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.
Related work in Portsmouth
- Bay window subsidence repairs
- Extension pulling away repairs
- Chimney stack repairs
- Resin injection ground stabilisation
- Gable end wall repairs
Floor joist repairs near Portsmouth
Each joist, sleeper wall and air brick at your Portsmouth property is itemised in the written quote, then fixed in price once the repair is specified.