Most roofs give plenty of warning before they fail. Here are the signs that mean it's time for a full replacement rather than another patch.
Why repair-vs-replace matters
A good repair on a sound roof is money well spent. The same money on a tired, end-of-life roof is throwing it away — you'll be back fixing the next failure within a year.
Below are the 10 signs we use, on site, to tell homeowners that it's time to budget for a new roof rather than another repair.
1. Your roof is over 30–40 years old
Concrete tiles last 40–60 years. Natural slate can last 80+. If your roof is approaching the upper end of its expected life and showing widespread issues, replacement usually makes more sense than repeated repairs.
2. Multiple slipped or missing tiles
One or two slipped tiles after a storm is normal. A dozen across the roof usually means the original nails or pegs have failed across the board, and you're going to keep losing tiles.
3. Cracked, delaminating or crumbling tiles
Concrete tiles can lose their surface coating and absorb water. Stone slates delaminate. Once tile failure is widespread, individual replacements stop being practical.
4. Persistent leaks that come back
If you've had the same leak fixed twice and it's back, the underlying problem is bigger than the visible damage. That's often a sign of failed underlay or perished battens — both of which need a full strip and re-roof.
A visible dip or wave in the roofline points to structural movement — sagging rafters, failed purlins or undersized timbers. This isn't a repair job; it's a structural fix and usually a full re-roof.
6. Daylight visible in the loft
Stand in your loft on a sunny day with the lights off. Pinpricks of daylight at the eaves or a glow under the felt are clues that your roof covering and underlay are no longer doing their job.
Old bitumen-based underlays go brittle and tear. Once you can see crumbling underlay from inside the loft, the roof is relying on the tiles alone — which is fine until wind-driven rain finds a way in.
8. Heavy moss and saturated tiles
Moss isn't just cosmetic — it holds moisture against tiles, accelerating freeze-thaw damage. Long-standing heavy moss is often a sign the roof has been neglected and is approaching end-of-life.
9. Damp patches on upstairs ceilings
Recurring damp on ceilings, especially after rain, points to roof failure rather than a localised leak. If repairs haven't solved it, replacement may be the only reliable fix.
An old, poorly insulated roof is a major source of heat loss. A re-roof is also the perfect opportunity to upgrade insulation and improve EPC ratings.
Not sure? Get a free assessment
If you've spotted some of these signs, get a proper survey before committing. We'll give you an honest answer — repair or replace — and explain exactly why. Read more on our new roofs and replacements service or our roof repairs service.
How long does a new roof take to install?
A typical three-bedroom semi takes 5–10 working days, weather permitting. Larger or more complex roofs take longer.
Do I need scaffolding for a new roof?
Yes — scaffolding is required for safe access on any full re-roof, and the cost is usually included in the quote.
Can I stay in the house during a re-roof?
Yes, in almost all cases. There'll be noise during working hours but the house remains habitable.
Evans Roofing & Maintenance Ltd, Witney, Oxfordshire. Call 07960 482233 for a free written quote.