Portsmouth · Hampshire
Roof structure repairs in Portsmouth
If the top of a wall at your Portsmouth property seems to lean out at the eaves, the roof may be spreading. Ties, collars and straps can usually hold it back, sometimes with an engineer’s design for the new load path.
Guide price from£335per rafter inc VAT

- Postcodes
- PO1, PO2, PO5
- Population
- about 210,000
- Area
- Hampshire
- Pricing region
- South East
What should you know about the ground under Portsmouth?
Portsmouth (PO1, PO2, PO5) has around 210,000 residents and sits in Hampshire. Nearby places we cover include Fareham (5 miles), Hayling Island (5 miles) and Havant (6 miles).
Shrinkable clay is widespread in Hampshire. Ground movement here is more often linked to soils, drains and trees than to mining. Across Hampshire, most homes are Victorian terraces in Portsmouth and Southampton, 1930s semis, and large post-war and new-build estates.
How much will roof structure repairs cost in Portsmouth?
For Portsmouth we use South East rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| 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 |
Which repair method suits a home in Portsmouth?
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
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
What happens when we carry out roof structure repairs in Portsmouth?
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.
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.
Signs you may need roof structure repairs
- Top of an outside wall leaning out at eaves level
- Horizontal cracks in the wall just below the eaves or ceiling line
- 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.
Roof structure repairs in Portsmouth: questions and answers
How much should I budget for roof structure repairs in Portsmouth?
Guide prices for roof structure repairs in Portsmouth 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 Portsmouth?
Yes. We take enquiries from across Portsmouth, including PO1, PO2, PO5, and from nearby places such as Fareham and Hayling Island. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Hampshire crack?
Central Hampshire is chalk, while the south around Portsmouth, Southampton and the New Forest fringe and the north-east around Farnborough sit on London Clay, Reading Beds and other clays and sands. The clay areas see seasonal movement near trees. Only an investigation can say why a particular building has moved.
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.
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 Portsmouth
- Structural crack repairs
- Retaining wall repairs
- Floor joist repairs
- Brick arch repairs
- Resin injection ground stabilisation
Roof structure repairs near Portsmouth
For a guide price on roof structure repairs in Portsmouth, try the quote tool or send photos of the ridge, the loft and the eaves.