Dorking · Surrey
Roof structure repairs in Dorking
Before buying or re-roofing a house in Dorking, it is worth knowing whether the frame can carry its covering. Send photos of the loft and the ridge, and we will tell you whether the timbers look adequate or need strengthening.
Guide price from£335per rafter inc VAT

- Postcodes
- KT23, RH4
- Population
- about 18,000
- Area
- Surrey
- Pricing region
- South East
What should you know about the ground under Dorking?
Dorking, Surrey: about 18,000 residents across postcode districts KT23, RH4. If you are just outside Dorking, we also cover Leatherhead (4 miles), Redhill (7 miles) and Cobham (8 miles).
Much of Surrey sits on clay that shrinks in dry summers and swells in wet winters. Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in Surrey: Victorian and Edwardian villas, 1930s semis and detached houses in the commuter towns, and post-war estates.
Symptoms that point to roof structure repairs
- Ridge line dipping in the middle when seen from the street
- Roof slope looking hollow or wavy between the ridge and the gutter
- Struts, collars or ties cut out or missing in the loft
Guide prices for roof structure repairs in Dorking
The ranges below reflect typical South East costs for roof structure repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| 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
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
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
From first photo to finished repair
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.
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.
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.
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 should I budget for roof structure repairs in Dorking?
Guide prices for roof structure repairs in Dorking 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.
Can you survey a property in Dorking?
Yes. We take enquiries from across Dorking, including KT23, RH4, and from nearby places such as Leatherhead and Redhill. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Surrey crack?
North Surrey sits on London Clay, the south on Weald Clay, with chalk along the North Downs and sands in the west. Large gardens with mature trees on clay make seasonal subsidence a familiar problem. 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.
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.
Related work in Dorking
- Crack stitching
- Subsidence insurance claim repairs
- Subsidence repairs
- Chimney stack repairs
- Concrete repairs
Roof structure repairs near Dorking
Get a free initial assessment of a sagging or spreading roof in Dorking from your photos or a call, and find out whether an engineer is needed.