Dartford · Kent
Floor joist repairs in Dartford
Houses in Dartford and across Kent 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£280per joist inc VAT
- Postcodes
- DA1
- Population
- about 51,000
- Area
- Kent
- Pricing region
- South East
What should you know about the ground under Dartford?
Dartford, Kent: about 51,000 residents across postcode districts DA1. If you are just outside Dartford, we also cover Bexley (3 miles), Swanley (4 miles) and Swanscombe (4 miles).
Much of Kent sits on clay that shrinks in dry summers and swells in wet winters. Parts of Kent lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Housing stock in Kent: Victorian terraces in the Medway towns, weatherboarded and Wealden houses, 1930s semis and seaside bungalows.
Guide prices for floor joist repairs in Dartford
Prices in Dartford are worked out on South East 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 | £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
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
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
From first photo to finished repair
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.
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.
Symptoms that point to floor joist repairs
- A gap opening up between the skirting board and the floor
- Soft or spongy boards near outside walls, hearths or the bathroom
- Ceiling cracks below that follow the line of the joists
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 Dartford?
Guide prices for floor joist repairs in Dartford 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.
Do you cover Dartford?
Yes. We take enquiries from across Dartford, including DA1, and from nearby places such as Bexley and Swanley. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Kent prone to subsidence?
North Kent sits on London Clay, central Kent on Gault and Weald Clays and the Downs on chalk, so shrinkable clay is widespread. East Kent around Deal and Dover had a small deep coalfield, worked until the late 1980s. Only an investigation can say why a particular building has moved.
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.
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 Dartford
- Chimney stack repairs
- Roof structure repairs
- Subsidence repairs
- Subsidence insurance claim repairs
- Lintel replacement
Floor joist repairs near Dartford
Send photos of the floor and the outside wall at your Dartford property for a free initial assessment and a no-obligation written quote.