Most roofs don’t fail overnight. They give warning signs for months, sometimes years, before a leak forces the issue. Spotting these signs early can save you from a costly emergency repair down the line. Here are eight worth taking seriously, and what each one usually means.
- Your roof is over 20–25 years old. Concrete and clay tiles typically last 40–60 years when well maintained, but the felt underlay beneath them usually doesn’t — and a failed underlay is often the real cause of a “roof” needing replacement.
- Daylight is visible through the loft. If you can see daylight through the roof timbers from inside the loft, water can get in the same way. This is one of the clearest signs that a full re-roof, not a spot repair, is needed.
- Tiles are cracked, slipped or missing in several places. A handful of slipped tiles is a simple repair. Tiles failing across the whole roof, however, usually means the fixings or the tiles themselves have reached the end of their life.
- The roofline is sagging. A dip or sag in the roofline can point to rotten timbers or a structural problem, and it’s worth having assessed quickly rather than left.
- Moss and algae cover large areas. A little moss is cosmetic. Heavy moss growth traps moisture against the tiles, though, which speeds up wear and can shorten the roof’s remaining life.
- You’re calling a roofer every year. If the same roof needs a repair call-out annually, the repairs are likely costing you more over time than a planned replacement would.
- Damp patches keep reappearing on ceilings. A one-off leak is a repair job. A damp patch that returns after being fixed usually means the underlying covering has failed more widely.
- Your energy bills have crept up. A failing roof affects insulation and ventilation, not just weatherproofing, so a steady rise in heating costs is sometimes an early clue.
Repair or replace?
None of these signs alone is a guaranteed answer — a roof with one or two of them might still be a repair job, while a roof with several is usually heading toward full replacement. Our guide on flat roof repair vs replacement covers the same decision for flat roofs specifically, and our 2026 new roof cost guide sets out what to budget for if replacement is the right call.
Getting a proper inspection
The only reliable way to know for certain is a proper roof inspection, ideally including the loft space, not just a look from the ground. A roofer who’s honest with you will tell you plainly if a repair will do, rather than recommending a full re-roof you don’t yet need. Booking one costs nothing more than a bit of your time, and it gives you a clear, evidence-based answer instead of a guess.
We carry out no-obligation inspections across St Margarets, and further out to Twickenham and Richmond upon Thames, and we’ll always give you our honest view before any work is agreed.
Related reading
- What to Do When Your Roof Is Leaking: An Emergency Checklist
- Slate vs Tile Roofing for Period Homes in Richmond upon Thames
- Fascias, Soffits & Guttering: A Homeowner’s Guide to Your Roofline
- Chimney Repairs, Re-Pointing and Removal Explained
- Velux & Roof Windows: Costs, Planning and Installation
- Storm Damage to Your Roof: What to Do and How Insurance Works
- Choosing a Trustworthy Roofer in South West London: 10 Questions to Ask
- Roofing in a Conservation Area: Rules for Richmond, Twickenham & St Margarets