Dartford · Kent
Roof structure repairs in Dartford
Many older roofs, in Dartford and across Kent alike, were built with slim purlins and few ties. A little historic movement is normal, so we check whether the roof is still moving before recommending how far the strengthening needs to go.
Guide price from£335per rafter inc VAT

- Postcodes
- DA1
- Population
- about 51,000
- Area
- Kent
- Pricing region
- South East
How do local ground conditions affect roof structure repairs in Dartford?
With roughly 51,000 people, Dartford spans postcode districts DA1 in Kent. Nearby, we also cover Bexley (3 miles), Swanley (4 miles) and Swanscombe (4 miles).
Kent is one of the parts of the UK where clay soils are most likely to move with the seasons. Parts of Kent lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Across Kent, most homes are Victorian terraces in the Medway towns, weatherboarded and Wealden houses, 1930s semis and seaside bungalows.
How we usually approach roof structure repairs
Tying in roof spread
New ties, collars or steel straps connect opposite rafters, or fix the rafter feet and wall plate firmly to the ceiling joists, so the outward thrust is resisted. Leaning wall heads are strapped back to the roof, and a badly spread roof may need partly rebuilding first.
Best for: Walls pushed out at eaves level by spreading rafters
Purlin and strut strengthening
Undersized purlins are strengthened with extra timber or replaced, and new struts are taken down to a load-bearing wall. Where there is no suitable wall, an engineer designs the load path. Temporary props hold the roof while members are changed.
Best for: Sagging slopes, slim purlins and struts removed from the loft
What happens during roof structure repairs, step by step?
Send photos
Photograph the roof from across the street, both slopes if you can, and the loft timbers with a torch. Include the eaves and any cracks just below them. From these we can usually tell sag from spread and whether an engineer is needed.
Written quote
You receive a no-obligation written quote listing each timber repair, any ties or straps, propping, scaffolding and making good. Once the repair is specified, the figure becomes a fixed price in writing.
Prop, strengthen and tie
The roof is propped where members are being changed, then rafters, purlins, struts and ties are repaired or added as specified. Coverings disturbed by the work are relaid, and building control inspects where the work needs it.
What to look for before calling about roof structure repairs
- Ridge line dipping in the middle when seen from the street
- Daylight through the tiles, or timber that is damp, stained or crumbling
- Struts, collars or ties cut out or missing in the loft
Roof structure repairs prices in Dartford
Guide prices below are for homes in Dartford, 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 |
|---|---|---|
| Repairing or doubling a rafter | £335 – £670 | per rafter |
| Purlin and strut strengthening | £1,350 – £3,350 | per roof |
| Tying in roof spread (straps and ties)est. | £895 – £2,800 | per roof |
Rules for roof structure repairs in England
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Questions about roof structure repairs in Dartford
How much will roof structure repairs cost in Dartford?
Guide prices for roof structure repairs in Dartford start from about £335 per rafter, 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, Dartford is covered, along with postcode districts DA1. We also cover nearby Bexley and Swanley.
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.
Why are there cracks just below the eaves?
A horizontal crack just below the eaves, along the front or back wall, is a common sign of roof spread. The rafters push the top of the wall outward and the masonry cracks where it hinges. Corroded wall ties can cause similar cracks, so the cause needs checking.
Can heavy concrete tiles damage a roof?
Yes, if the frame was designed for lighter slate or tiles and was not strengthened. The extra weight makes rafters and purlins sag and can bring on roof spread. Before re-roofing in a heavier material, have the structure checked and notify building control.
Other structural repairs in Dartford
- Crack stitching
- Brick arch repairs
- Subsidence insurance claim repairs
- Structural surveys and crack monitoring
- Lintel replacement
Roof structure repairs near Dartford
Get a free initial assessment of a sagging or spreading roof in Dartford from your photos or a call, and find out whether an engineer is needed.