Crawley · West Sussex
Roof structure repairs in Crawley
Roofs in Crawley that were re-covered with heavier concrete tiles, or had struts cut out for a loft room, often start to sag years later. Spotting which change caused the movement is the first step to a repair that holds.
Guide price from£335per rafter inc VAT

- Postcodes
- RH10, RH11
- Population
- about 120,000
- Area
- West Sussex
- Pricing region
- South East
Is West Sussex prone to ground movement?
Crawley, West Sussex: about 120,000 residents across postcode districts RH10, RH11. If you are just outside Crawley, we also cover Horley (4 miles), Horsham (7 miles) and East Grinstead (8 miles).
Shrinkable clay is widespread in West Sussex. Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in West Sussex: Wealden cottages, 1930s semis and bungalows on the coast, and new-town estates in Crawley.
Guide prices for roof structure repairs in Crawley
Guide prices below are for homes in Crawley, 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 |
Methods for roof structure repairs
Wall plate replacement
Rotten or crushed wall plates are replaced in short lengths while the rafters above are propped, and bedded on the wall in mortar. The plate is then strapped down to the masonry. It is often combined with rafter foot splices along the same run.
Best for: Rot along the eaves where rafters bear on the wall
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.
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.
Symptoms that point to roof structure repairs
- Daylight through the tiles, or timber that is damp, stained or crumbling
- Struts, collars or ties cut out or missing in the loft
- 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
What is the price of roof structure repairs in Crawley?
Guide prices for roof structure repairs in Crawley 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 carry out roof structure repairs in Crawley?
Yes. We take enquiries from across Crawley, including RH10, RH11, and from nearby places such as Horley and Horsham. Send photos for a free initial view and we will tell you what happens next.
Does the ground around Crawley cause cracking?
North West Sussex around Crawley and Horsham sits on Weald Clay, the South Downs are chalk, and the coastal plain has brickearth and gravels. The Weald Clay is prone to shrink-swell movement near trees. 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.
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.
More repairs we carry out in Crawley
- Crack stitching
- Floor joist repairs
- Retaining wall repairs
- Bowing wall repairs
- Extension pulling away repairs
Roof structure repairs near Crawley
Every rafter, purlin and tie on the job in Crawley is listed in the written quote, which becomes a fixed price in writing once the repair is specified.