Northamptonshire · England
Floor joist repairs in Northamptonshire
Northamptonshire has its own mix of ground and building types, and that shapes how floor joist repairs is done here. Much of Northamptonshire sits on clay that shrinks in dry summers and swells in wet winters.
Guide price from£245per joist inc VAT
- Area
- Northamptonshire
- Pricing region
- East Midlands
- Ground
- Shrinkable clay widespread
- Towns listed
- 6
Is Northamptonshire prone to ground movement?
Northamptonshire sits largely on Lias clay and Jurassic ironstones and limestones, with historic ironstone quarrying around Corby and Kettering. The clay vales are prone to shrinkage near trees.
Historic ironstone working has left disturbed ground in places. Housing stock in Northamptonshire: Ironstone and limestone cottages, Victorian terraces in Northampton and Kettering, and new-town estates in Corby.
Guide prices for floor joist repairs in Northamptonshire
For Northamptonshire we use East Midlands rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| Item | Guide price | Per |
|---|---|---|
| Splicing or sistering a damaged joist | £245 – £390 | per joist |
| Whole room of joists and boards | £1,950 – £5,900 | per room |
| Sleeper wall rebuild and ventilationest. | £390 – £1,450 | 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
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
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.
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.
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
- Soft or spongy boards near outside walls, hearths or the bathroom
- A gap opening up between the skirting board and the floor
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.
Floor joist repairs near you in Northamptonshire
Frequently asked questions
Does the ground around Northampton cause cracking?
Northamptonshire sits largely on Lias clay and Jurassic ironstones and limestones, with historic ironstone quarrying around Corby and Kettering. The clay vales are prone to shrinkage near trees. Historic ironstone working has left disturbed ground in places. Only an investigation on site can say why a particular building has moved.
How much will floor joist repairs cost in Northamptonshire?
On East Midlands rates, floor joist repairs starts from about £245 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.
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.
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.