Leaks and repairs
Signs You Need a New Roof, and When a Repair Will Do
Slipped tiles, a stain on the ceiling or daylight in the loft can mean a small repair or a roof at the end of its life. What decides it is how far the damage has spread and how the roof's age compares with the lifespan of its covering. Here are the signs that point to a new roof, how to check for them without climbing up, and what a repair costs next to a replacement.
Which signs mean a repair and which mean a new roof
Most of the seven signs Checkatrade lists for a roof that may need replacing can also turn up on a roof that needs only a repair. What separates the two is how far the damage has spread.
The table adds a sagging roof to those seven. Repair prices are Checkatrade’s UK rates excluding VAT, with tile and slate rates covering repairs up to 3 m² and scaffolding charged on top.
| Sign | Repair or new roof | Repair price, excluding VAT |
|---|---|---|
| Water stains on ceilings or walls | A repair once the leak is traced, unless other signs show too | Depends on the cause |
| Misshapen, sunken or missing tiles | A repair if they are in one patch, a new roof if they are across the slopes | £90 to £160 per m² for plain tiles, £150 to £220 per m² for natural slate |
| Worn chimney flashing | Usually a repair | £50 to £70 per metre, or £80 to £120 per metre for stepped flashing |
| Heavy moss and mould | Depends on the condition of the tiles underneath | No set rate |
| Daylight showing in the loft | A repair if it is one gap, a new roof if light shows in several places | Tile or slate rates, as above |
| Damaged or rotten underlay | A new roof if the rot is widespread, because the tiles and battens have to come off to replace it | No set rate |
| A roof over 20 years old | Neither on its own, so look for the other signs | None |
| A sagging roof | Strengthening, unless the roof structure has to be replaced | About £25 per metre for extra rafters, £30 to £40 per metre for binders or purlins with struts |
How to check your roof without climbing on it
You can look for every visible sign from the ground, an upstairs window or the loft. Leave anything closer to a roofer, and never climb onto the roof.
Stay off the roof
Tiles and slates can crack or slide underfoot. A slip on a pitched roof can end in a fall to the ground, and every tile you crack adds to the repair.
Look at each slope from the ground, then from any upstairs window with a view of the roof. Go into the loft only if it is safe and dry underfoot, take a torch and keep your hands off wiring and light fittings.
What to look for from the ground and in the loft
- Tiles or slates that have slipped, cracked, sunk or gone missing
- A ridge or slope that dips instead of running straight
- Lead flashing around the chimney that looks worn or has pulled away
- Heavy moss or mould across the tiles
- Water stains on upstairs ceilings and the tops of walls
- Daylight showing through the roof from inside the loft
- Underlay that is torn, damp or rotten
Is a roof over 20 years old due for replacement?
Most roofs last around 20 years without needing work, on Checkatrade’s figure, and a roof past that age is on its list of signs. Age alone does not mean a new roof, because the lifespan of a roof varies with what covers it.
Checkatrade gives clay and concrete tiles 25 to 40 years and metal roofs 50 to 100 years. SSQ, a natural slate supplier, says a natural slate roof made from high-quality materials and installed correctly can last over 100 years. On a flat roof, Checkatrade’s figures are 15 to 20 years for torch-on felt, 20 to 30 years for asphalt, up to 30 years for GRP fibreglass and 30 to 50 years for EPDM rubber that is professionally installed and maintained.
Treat the roof’s age as a reason to look for the other signs, not to replace it on sight. If you are buying a house, a pre-purchase roof survey shows the roof’s condition before you commit, and B&S Roofing in Eastwood offers them.
What a repair costs next to a new roof
A new gable roof costs £7,000 to £16,250 and a hip roof £9,250 to £18,000, both for a 64 m² roof, on Checkatrade’s UK prices excluding VAT. Scaffolding and stripping the old roof add £700 to £1,300 and £1,000 to £2,500 on top.
A repair stays far below that while the damage is confined to one area, because roof repair costs rise with each m² of tiles and each metre of ridge or flashing replaced. Scaffolding does not shrink with the repair, though. A single scaffold up to 10 m high costs around £625 a week, and each separate visit that needs one pays for it again.
Three repairs on an older concrete tile roof, done in one visit
| Concrete plain tiles, 3 m² at £90 to £120 per m² | £270 to £360 |
|---|---|
| Dry ridge, 6 m at £50 to £70 per metre | £300 to £420 |
| Code 5 lead flashing, 3 m at £50 to £70 per metre | £150 to £210 |
| Single scaffold up to 10 m high, 1 week | £625 |
Total £1,345 to £1,615
Prices exclude VAT. Book the repairs together, because each extra visit that needs a scaffold adds around £625 more.
That bill makes sense while the rest of the roof is sound. Once the faults show across the slopes, each repair pays for scaffolding on a roof that is still wearing out.
Replacing part of a roof
The Planning Portal says a building control application is not normally needed to repair or re-cover a roof if less than 50 per cent of the roof and less than 25 per cent of the total building envelope (the walls, floor, roof, windows, doors, roof windows and roof-lights) is affected. Approval is required if you go past either limit, make structural alterations, or change to a covering that performs significantly differently in a fire or makes the roof covering 15 per cent or more heavier.
Getting quotes for a repair and a new roof
When the signs are mixed, ask a roofer to price the repair and a new roof separately, and to say which they would do. A request for a new roof quote gets a new roof price and nothing to compare it with.
Asking a roofer to look at an older roof
Do this
Our concrete tile roof is about 25 years old. Tiles have slipped on the rear slope and there is daylight by the chimney in the loft. Please quote for repairing those and for a new roof, and tell us which you would do and why.
Not this
Can you come and give us a quote for a new roof?
Compare the guarantee on each quote as well as the price. Of the Nottingham roofers compared on how long they guarantee their work, Roofcare (Midlands) in West Bridgford guarantees repairs for 5 years and new roofs for 10 years, and Premier Roofing Solutions in New Basford gives a 10-year warranty on any new roof.
Common questions
How do I know if my roof needs replacing or just repairing?
Look at how far the damage has spread. A few slipped tiles, one length of worn flashing or a single damp patch is usually a repair, while sunken tiles across the slopes, rotten underlay or daylight in several places points to a new roof. If the signs are mixed, ask a roofer to quote for both.
Should I replace my roof after 20 years?
Not on age alone. Checkatrade says most roofs last around 20 years without needing work but gives clay and concrete tiles 25 to 40 years, and SSQ, a slate supplier, says a natural slate roof made from high-quality materials and installed correctly can last over 100 years. Replace it when the age comes with other signs, such as sunken tiles or rotten underlay.
Is it cheaper to repair or replace a roof?
A repair is cheaper while the damage is confined to one area. Checkatrade's UK rates, excluding VAT, are £90 to £220 per m² for tile or slate repairs against £7,000 to £16,250 for a new 64 m² gable roof. Once faults spread across the roof, each repair visit needing a scaffold adds around £625 a week, and a new roof starts to make more sense.
Can you replace just part of a roof?
Yes, and a building control application is not normally needed if the work affects less than 50 per cent of the roof and less than 25 per cent of the total building envelope. Go past either limit and the Planning Portal says building regulations approval is required.
Does home insurance pay for a new roof?
Usually not when the roof has simply worn out. Home insurance often covers sudden damage, such as a storm, but wear and tear is usually not covered.
Can a sagging roof be repaired?
Often, by strengthening the roof structure instead of replacing it. Checkatrade prices extra rafters at about £25 per metre and binders or purlins with struts at £30 to £40 per metre, excluding VAT, against £6,500 to £20,000 or more for a new roof structure. Structural alterations need building regulations approval.
Where the figures come from
- Checkatrade, roof replacement cost guide read 2026-09-16
- Checkatrade, roof repair cost guide read 2026-09-16
- Checkatrade, flat roof replacement cost guide read 2026-09-16
- SSQ (natural slate supplier), slate roof life expectancy read 2026-09-16
- Planning Portal, building regulations for work to an existing roof read 2026-09-16
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