Key takeaways
- Most pitched tile and slate roofs last decades, while flat felt roofs often need replacing after 15 to 20 years.
- Warning signs include leaks and damp in the loft, slipped or missing tiles, a sagging roofline and daylight showing through the boards.
- A single leak is often a repair, not a new roof. Widespread or age-related damage is when replacement makes sense.
- If you spot several signs together, get a roofer to inspect before small problems turn into structural ones.
A roof rarely fails overnight. It gives you clues first, and catching them early is the difference between a cheap repair and a full replacement. Here are the signs worth acting on, and how long roofs tend to last.
How long roofs last
Lifespan depends on the material. Concrete tiles typically last 40 to 60 years, clay tiles often longer, and natural slate can last a century or more. Flat roofs are the short straw: traditional felt flat roofs usually need replacing after about 15 to 20 years, though modern rubber membranes last longer. If your roof is near the top of its range, age alone is a reason to have it checked.
Signs to look for
From inside, go up to the loft on a bright day. Daylight through the boards, damp patches, a musty smell or staining on the timbers all point to water getting in. From outside, look for slipped, cracked or missing tiles, a ridge line that dips or sags, failed lead flashing around the chimney, and heavy moss or plant growth that holds moisture against the surface. Water stains on upstairs ceilings and rising heating bills can also trace back to the roof.
The catch: one or two of these on their own often mean a localised repair, not a new roof. It is the combination, especially alongside age, that tips the balance towards replacement.
Repair or replace?
A few slipped tiles or a single leak around flashing is usually a straightforward fix. Consider a full replacement when damage is widespread, the structure is sagging, repairs are becoming frequent, or the roof has simply reached the end of its life. A roofer can tell you which camp you are in after an inspection. For budgeting, see our UK home improvement cost report, and our guide to improvements that add the most value.
FAQ
How long should a roof last?
Concrete tiles last roughly 40 to 60 years, clay tiles and slate often longer, and felt flat roofs around 15 to 20 years. Material, exposure and how well it was fitted all affect the real figure.
Can I just repair my roof instead of replacing it?
Often, yes. Isolated slipped tiles or a single leak are usually repairs. Replacement makes more sense when damage is widespread, the roof is sagging, or it has reached the end of its lifespan.
Is moss on the roof a problem?
A little is normal, but heavy growth holds moisture against the tiles and can work into gaps, especially with frost. It is worth clearing and keeping an eye on rather than ignoring.