Roof life is published as a range rather than a number, and no single authoritative body consolidates it. The figures below are the ranges the trade works to, drawn from consumer cost guides citing NHBC, NFRC and BRE data. They describe typical outcomes, not guarantees.
Typical UK lifespans by covering
- Concrete tile: 40 to 60 years
- Clay tile: 60 to 100 years or more
- Natural slate: 80 to 150 years
- Fibre-cement slate: 30 to 50 years
- Torch-on felt: 15 to 20 years
- GRP: 30 to 40 years
- Guttering: around 20 years
Poor installation can halve any of them. A slate fixed with the wrong nail, or a membrane sagging between rafters so water pools rather than runs off, fails on a timescale set by the workmanship rather than the material.
EPDM is the one figure nobody agrees on
Checkatrade puts EPDM flat roofing at 30 to 50 years. Other published sources put it at 25 to 40. Taken together the range runs from 25 to 50, which is close to a twofold spread on the same product, and there is no settled figure to report. Anyone quoting a precise EPDM lifespan has picked one source and dropped the rest.
Twenty-five years is still ahead of torch-on felt at 15 to 20, and that gap is the practical point. Felt is the cheapest flat roof to install and usually the dearest across forty years, because it needs replacing two or three times in that period.
The covering outlives what sits under it
This is the part that decides when a pitched roof ends, and it is the part you cannot see.
Bitumen underlay cracks at 30 to 40 years. Galvanised nails rust out at 40 to 50. Both of those sit beneath a natural slate rated at 80 to 150. So the components with the shortest life on a Victorian roof are the ones nobody looks at, and they fail while the slate is barely halfway through its own span.
That is why a 90-year-old South London slate roof reaches the end of its working life with most of its slates still perfectly serviceable. Nails let go and slates begin slipping one at a time. The underlay beneath tears and stops catching the wind-driven rain that always gets past a slate covering. Nothing has failed that you can see from the pavement.
Why "the slate looks fine, so the roof is fine" is wrong
A ground-level look tells you about the covering and nothing else. On the stock across Southwark, Lambeth and Lewisham the covering is the longest-lived thing on the roof, so it is the worst possible thing to judge the roof by.
If you are buying a Victorian or Edwardian house and the survey says only that the roof appears serviceable, the question worth putting to a roofer is the age and condition of the underlay and the fixings, not the slate. That is what forces the re-roof and what sets the timing of it.
Salvage is what makes an old slate roof affordable to renew
A roofer who strips carefully, sorts the sound slates and relays them is reusing a material with decades of life left in it, and cutting the largest line on a slate quote in the process. One who has priced an all-new order may be faster on site, but the two quotes will look nothing alike and you should know which one you are reading.
Ask any roofer quoting on a slate roof whether the price assumes salvaged or new slate, and what proportion of the existing covering is expected to survive the strip.
A roof rarely announces the end of its life, which is why the age of what lies under the covering is worth knowing before it forces the decision for you.