The short answer
Start with paperwork, then read the roof. A completion certificate, a past invoice or the seller's records can give a date. Without them, the covering, the underlay and the timbers in the loft give clues, though each gives a range, not a date. A roofer can read these together, show you photographs of what points to its age, and tell you whether age matters for the repair.
Nobody can read an exact date off a roof, but paperwork and a close look at the covering and the loft narrow it down well enough to plan.
Paperwork that can give a date
Look in the house before you look at the roof. If the roof was replaced in a way that needed Building Regulations approval, a completion certificate may exist, and Somerset Building Control's FAQ covers copies of them and says records are kept for 15 years. Ask your solicitor whether the certificate came with the sale. Past invoices, a guarantee certificate from an earlier roofer, or a note from a surveyor can also fix a date.
What if there is no paperwork?
Ask the seller or the previous owner, and ask neighbours with the same house, because a terrace or an estate was often roofed in one go. Do not take their word as proof, but a story that three owners tell the same way is worth noting.
Many re-roofs on an existing house did not need an application at all. The Planning Portal test is that work affecting less than 25 per cent of the building envelope and less than 50 per cent of the roof normally needs no building control application, so a missing certificate proves nothing about age. Somerset Building Control can say what it holds for your address.
What the covering tells you
The covering itself shows wear. Slate, if well maintained, can last 100+ years, according to CORC, so a slate roof can be far older than the rest of the house suggests. Clay tile has a BRE minimum life expectancy of 60 years, and Marley says the same figure does not apply to concrete, which it puts at around 60 years with no guarantee. Those are lifespans, not ages, and a sound old roof is not the same thing as a worn one.
Which signs point to an older covering?
Look for tiles with a rough, flaky surface, slates that have started to delaminate into layers, deep moss growth and a ridge line that dips. Patches of new, brighter tiles among darker ones show past repairs. If every tile has the same weathered tone and the same style, it is probably original or all one age.
Roofers call this reading the roof, and a close view, from a drone or a ladder at the gutter line, beats one from the pavement. Our guide to drone roof surveys shows how a camera can bring the surface closer.
Clues in the loft and underlay
The loft preserves evidence that the weather cannot reach. The underlay is a waterproof sheet beneath the covering, resting on the rafters, with battens (small timber laths) fixed over it, and it ages differently from the tiles above. Brittle, torn or sagging underlay points to a roof that has had many years of use. A roof with no underlay at all, with bare boards or open gaps under the covering, is usually an old one.
What do the timbers show?
Check the rafters and battens. Dark staining, a flaky surface and fine holes suggest age and past damp. Nail heads that are rusted and streaked with orange or brown tell you the fixings have been exposed to moisture for a long time. Old nails that have lost their grip, a condition roofers call nail sickness, let slates slip.
None of this gives a date, and a roof of any age can look tired if it has leaked. A roofer who reads the covering, the underlay and the timbers together can give you a range and, more usefully, say how much working life is left. Our guide on checking a roof from the loft shows how to do it safely.
Why the answer matters
Age helps you plan, but it does not decide on its own. A well-kept slate roof of a great age may need only a few repairs, and a younger roof laid badly may need more. What counts is the condition, the fixings and the fall of the roof, and what each repair will buy you.
Should I replace a roof because it is old?
Not on age alone. Replace it when repairs stop holding, when the battens are rotten, or when the fixings have failed across a whole slope. Until then, targeted repairs are often the better buy. A roofer should show you photos of the cause, not just quote a total.
If you are buying, tell the roofer the date of the sale and ask them to describe the roof in plain words. For an older home, remember that a pre-2000 building may contain asbestos materials, and HSE says to assume it does until it is checked. Our roof inspections page explains the options for a closer look.
If you would like a roofer's reading of your own roof, we can survey it and walk you through the photographs.
More on the age of a roof
Can a roofer tell the exact year a roof was laid?
No. A roofer reads the covering, the underlay and the timbers and gives a range, such as laid within a few decades. The exact year comes only from paperwork. If the date matters for a sale or a claim, look for a certificate or invoice first.
Is an older roof always a problem for buyers?
No. A long-lived covering that has been looked after can outlast a younger one that was laid badly. What matters is condition. Ask the roofer for photographs of the fixings, battens and flashings, and a view on how long the roof can carry on with repairs.
The full picture: Roof inspections in Taunton ยท More short answers