Dorchester · Dorset
Roof structure repairs in Dorchester
Many older roofs, in Dorchester and across Dorset 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£310per rafter inc VAT
- Postcodes
- DT1
- Population
- about 17,000
- Area
- Dorset
- Pricing region
- South West
What is the ground like in Dorset?
Dorchester is in Dorset and takes in postcode districts DT1. About 17,000 people live there. If you are just outside Dorchester, we also cover Weymouth (7 miles), Yeovil (18 miles) and Poole (20 miles).
Parts of Dorset have clay that can shrink near trees in dry spells. Ground movement here is more often linked to soils, drains and trees than to mining. Across Dorset, most homes are stone and brick villages, Victorian villas in Bournemouth, and inter-war and post-war semis.
Guide prices for roof structure repairs in Dorchester
The ranges below reflect typical South West 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 | £310 – £620 | per rafter |
| Purlin and strut strengthening | £1,250 – £3,100 | per roof |
| Tying in roof spread (straps and ties)est. | £825 – £2,600 | 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
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.
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
- Horizontal cracks in the wall just below the eaves or ceiling line
- Struts, collars or ties cut out or missing in the loft
- Top of an outside wall leaning out at eaves level
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 Dorchester?
Guide prices for roof structure repairs in Dorchester start from about £310 per rafter, including VAT, on South West rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Dorchester?
Yes, Dorchester is covered, along with postcode districts DT1. We also cover nearby Weymouth and Yeovil.
Is the ground in Dorset prone to subsidence?
Dorset mixes chalk downs, Oxford and Kimmeridge Clays in the vales, and the sands and gravels of the Poole basin. Clay vales can shrink and swell, and parts of the coast are known for landslip. 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.
Do roof structure repairs need building control?
Usually yes, where the structure is strengthened or altered, or the covering becomes significantly heavier. In England and Wales that falls under Part A, in Scotland it generally needs a building warrant, and in Northern Ireland council building control approves it. We deal with building control where the work needs it.
Other structural repairs in Dorchester
- Bay window subsidence repairs
- Crack stitching
- Retaining wall repairs
- Floor joist repairs
- Concrete repairs
Roof structure repairs near Dorchester
Send photos of the roof from the street and the loft timbers at your Dorchester property for a free initial assessment and a no-obligation written quote.