Belfast · County Antrim
Roof structure repairs in Belfast
A dipping ridge or a wavy roof slope in Belfast is usually a timber problem, not a tile problem. We look at the rafters, purlins, struts and ties from the loft, and at the wall heads from outside, before suggesting how to strengthen it.
Guide price from£265per rafter inc VAT

- Postcodes
- BT1, BT2, BT7
- Population
- about 350,000
- Area
- County Antrim
- Pricing region
- Northern Ireland
What is the ground like in County Antrim?
Belfast, County Antrim: about 350,000 residents across postcode districts BT1, BT2, BT7. We also take enquiries from nearby Newtownabbey (4 miles), Lisburn (7 miles) and Carrickfergus (10 miles).
Shrinkable clay is less common in County Antrim than in south-east England. Historic brine and salt working has caused ground movement in parts of County Antrim in the past. Typical buildings in County Antrim: Red-brick terraces in Belfast, Victorian villas, and post-war and newer estates.
What should you budget for roof structure repairs in Belfast?
Prices in Belfast are worked out on Northern Ireland 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 | £265 – £530 | per rafter |
| Purlin and strut strengthening | £1,050 – £2,650 | per roof |
| Tying in roof spread (straps and ties)est. | £705 – £2,200 | per roof |
Repair options we may recommend
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
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
What to expect when we carry out roof structure repairs
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.
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.
Is it time for roof structure repairs? Common signs
- Top of an outside wall leaning out at eaves level
- Roof slope looking hollow or wavy between the ridge and the gutter
- Struts, collars or ties cut out or missing in the loft
Rules for roof structure repairs in Northern Ireland
In Northern Ireland, the Building Regulations (Northern Ireland) 2012 apply and the council’s building control service approves structural work such as underpinning; minor like-for-like repairs usually need no approval. The Party Wall Act does not apply in Northern Ireland, so work to shared walls depends on deeds and agreement with neighbours.
Your roof structure repairs questions
How much will roof structure repairs cost in Belfast?
Guide prices for roof structure repairs in Belfast start from about £265 per rafter, including VAT, on Northern Ireland rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Belfast?
Yes, Belfast is covered, along with postcode districts BT1, BT2, BT7. We also cover nearby Newtownabbey and Lisburn.
Is the ground in County Antrim prone to subsidence?
County Antrim is largely basalt over chalk, with soft estuarine 'sleech' along Belfast Lough that is notorious for settlement. Historic salt mining is recorded near Carrickfergus. 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.
What is roof spread?
Roof spread is when the feet of the rafters move outward because nothing is tying them together firmly enough. As they spread, the ridge drops and the tops of the walls are pushed out, often with a horizontal crack below the eaves. It is fixed by adding ties, collars or straps, sometimes with rebuilding.
Other structural repairs in Belfast
- Subsidence repairs
- Resin injection ground stabilisation
- Brick arch repairs
- Chimney stack repairs
- Gable end wall repairs
Roof structure repairs near Belfast
Seen the ridge dip at your Belfast home? Photograph it from across the road, add a few loft shots, and we will tell you what it likely needs.