Sevenoaks · Kent
Roof structure repairs in Sevenoaks
Many older roofs, in Sevenoaks 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
- TN13
- Population
- about 30,000
- Area
- Kent
- Pricing region
- South East
Is Kent prone to ground movement?
With roughly 30,000 people, Sevenoaks spans postcode districts TN13 in Kent. We also take enquiries from nearby Tonbridge (6 miles), Swanley (9 miles) and Bromley (10 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 roof structure repairs in Sevenoaks
Prices in Sevenoaks 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 |
|---|---|---|
| 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 |
Methods for roof structure repairs
Repairing or doubling rafters
Cracked, sagging or rotten rafters are strengthened by fixing a new timber alongside, often called doubling, and rotten rafter feet are cut back and spliced. The work is usually done from inside the loft with the tiles left in place, unless the covering is coming off anyway.
Best for: Individual rafters that have cracked, sagged or rotted at the feet
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
From first photo to finished repair
Loft and outside survey
On site we check rafter sizes and spacing, purlins, struts, ties and wall plates, look for rot and past alterations, and measure any lean at the wall head. The covering is noted too, because its weight affects the repair.
Engineer’s design where needed
Where purlins, struts or ties must be redesigned, or the roof carries a heavier covering, an independent chartered structural engineer is appointed to specify the work. We can arrange this, and their design sets the sizes and fixings.
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.
Symptoms that point to roof structure repairs
- Top of an outside wall leaning out at eaves level
- Roof slope looking hollow or wavy between the ridge and the gutter
- Ridge line dipping in the middle when seen from the street
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.
Frequently asked questions
How much will roof structure repairs cost in Sevenoaks?
Guide prices for roof structure repairs in Sevenoaks 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 Sevenoaks?
Yes. We take enquiries from across Sevenoaks, including TN13, and from nearby places such as Tonbridge 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.
Do I need a structural engineer for roof repairs?
For like-for-like repairs to a few rafters, often not. Where purlins, struts or ties are being redesigned, the covering is getting heavier or the walls are being pushed out, you usually do. Where the repair needs an engineer’s design or sign-off, an independent chartered structural engineer is appointed, and we can arrange this.
Can the roof be strengthened without removing the tiles?
In most cases, yes. Doubling rafters, adding struts and fitting ties can all be done from inside the loft with the coverings in place. Tiles usually only come off where timber near the eaves is badly decayed, or the roof is being re-covered anyway.
Other structural repairs in Sevenoaks
- Underpinning
- Structural crack repairs
- Wall tie replacement
- Boundary and garden wall repairs
- Lintel replacement
Roof structure repairs near Sevenoaks
Get a free initial assessment of a sagging or spreading roof in Sevenoaks from your photos or a call, and find out whether an engineer is needed.