The short answer
There is no single figure that applies to every system. How long a dry ridge lasts depends on the maker, the parts used, how well it was fitted and how exposed the roof is. Ask for the data sheet, check whether the kit was tested to BS 8612, and treat any warranty length as a separate matter from how long the parts will last.
Be wary of anyone who quotes a neat number of years. A dry ridge is a set of parts, and each part ages in its own way.
Why one number cannot cover every kit
A dry ridge is not a single material. It is a ridge tile of clay or concrete, a batten of treated timber, a ventilated strip of flexible membrane, plastic or metal brackets and clips, and screws or nails. Each of those ages at its own pace. The tile may outlast the roof it sits on, while a clip or an end cap is expected to be the first piece to need attention.
Is the ridge tile or the fixing the limit?
It depends on the system. Clay and concrete tiles are long-lived materials. Marley, a tile maker, describes its concrete roof tiles as expected to serve for around 60 years, and states plainly that this does not amount to a guarantee or warranty. That is a tile figure, not a figure for a whole dry-fix kit. The plastic and metal parts around the tile depend on the maker's choice of material and how it stands up to sunlight and weather, so the data sheet for the kit is where those details sit.
The parts differ, and the weakest of them sets the pace for the system.
What decides how long it lasts
Four things matter more than any figure on a box. The first is the quality of the kit, which is why testing counts. The second is the fixing: a ridge held to sound timber with the right screws will outlast one fixed to a rotten ridge board. The third is the fitting, since a roll stuck to a dirty surface will lift long before the tiles show any wear. The fourth is the setting of the house itself.
Does exposure shorten the life of a ridge?
It can. A house on a hilltop or an open stretch of the Levels takes more wind than one tucked into a street of terraces, and wind is what works loose fixings. Strong sun fades and hardens plastic over the years, and trees overhead drop leaves and moss into the joints. None of those ends a roof overnight, but they shape how the ridge ages, and a system that suits a sheltered street may suffer on an exposed one.
Maintenance counts too. A ridge checked after a storm and cleared of debris gets more from its parts than one nobody looks at.
Warranty length is not lifespan
A warranty is a promise from the maker or fitter about what they will put right if something fails within a set time. A lifespan is how long the parts are likely to keep working. The two are not the same, and a long warranty does not prove a long life. The terms matter more than the number of years: what is covered, who pays for labour, and what the owner must do to keep the cover valid.
What should I ask about a warranty?
Ask whether it covers parts only or the fitting as well. Ask what happens if the maker stops trading. Ask whether the cover depends on a particular installer or on using only the maker's own parts. Ask for the terms in writing, not on a leaflet. These are fair questions for any roofer to answer, and the answers tell you more than a headline number does.
For our part, the survey and written price come first, and you see the kit's data sheet before anything is ordered. If you are comparing two quotes, check each one names the system and its maker, not only the word dry-fix.
Reading a data sheet and the BS 8612 test
The data sheet is the maker's own paper on the product. It names the tile profiles the kit suits, the pitch limits, the fixings and the order the parts go on. It may also state that the kit was put through the BS 8612 tests, which cover dry-fixed systems for these roof edges. BS 8612:2018 is the current version at BSI.
Does passing BS 8612 prove a kit will last?
It shows that the system as a whole has been put through the tests in the standard, which is a better sign than a kit with no tests behind it. It does not predict a number of years, and it says nothing about how the kit is fitted on your roof. Treat it as a minimum worth asking for, and read the rest of the data sheet alongside it.
If your ridge is already fitted and you want to know how it is holding up, our page on dry ridge failure lists the signs, and BS 8612 dry-fix explains the test. The hub page, dry ridge and verge, sets out how a full system goes together.
More on how long a ridge lasts
Does a mortar ridge outlast a dry ridge?
Neither has a fixed life. Mortar cracks as the roof moves, and Marley notes the 2014 BS 5534 revision stopped treating it as enough by itself for ridge and hip tiles. A dry system avoids that weakness, but a poor kit or careless fitting brings its own faults.
Should I check a dry ridge as it gets older?
A look from the ground after a storm is sensible, using binoculars if you have them. Watch for tiles out of line, a lifted strip along the join, cracked plastic at the ends or marks on the ceiling below. If any of those appear, ask for a survey.
The full picture: Dry ridge and verge repairs in Taunton ยท More short answers