The short answer
Published guides put a polycarbonate conservatory roof at about 10 years, and some at 10 to 15. HomeBuilding gives a typical lifespan of 10 years; The Eco Experts says about 10 to 15 years, covering glass as well as polycarbonate. Treat both as guides, not promises. Sunlight, sheet grade, the seals and the fitting all move the figure for any one roof.
Ten years is a useful planning figure, not a deadline. Your own roof will tell you more than any guide, once you know which signs to check.
What the published figures say
Two national guides give a number worth knowing. HomeBuilding describes a typical lifespan of 10 years for a polycarbonate conservatory roof. The Eco Experts says about 10 to 15 years, and groups glass and polycarbonate together when it does. Planning for that window early lets you budget calmly, rather than finding out in the first heavy storm that the sheets have let go.
Is that a guarantee?
No. A lifespan figure describes what a roof of this kind often achieves, and a warranty on a product or on workmanship is a different thing again. A roof can be sound at 14 years and a badly fitted one can be tired at 7. Treat the published range as the point where you start looking at the roof more closely, not the day it stops working.
The figure is also lower than the one for other roofs on your house. A slate roof can run far longer than a plastic one, because slate is a stone and polycarbonate is a plastic that responds to sunlight and heat. That gap is the main reason conservatory roofs are replaced more often than the house roof beside them.
What shortens the life of the sheets
Ultraviolet light is the slow enemy. Better sheets carry a protective layer on the upper face to resist it. Where that layer is thin or has worn, the plastic yellows, turns brittle and starts to craze.
What else wears a polycarbonate roof out?
Heat and cold make the sheets expand and shrink all day, every day, and they slide a little against the bars as they do. That movement can wear the seals and loosen caps. Dirt, moss and algae are another cause, because growth sitting on the surface holds water against the edges. Our answer on moss on a polycarbonate roof covers cleaning without damaging the surface.
Poor ventilation, a sagging frame and open sheet ends matter too. An end of a hollow sheet left unsealed lets in dust, insects and damp, and green growth then shows inside the cells where nobody can wipe it away. A roof with a failing end seal can look much older than its years from inside. Two neighbours with the same roof can differ by years, and a roof that is still sound after a decade is usually one whose sheets were cleaned, whose caps were checked and whose ends stayed sealed.
Signs your roof is near the end
Look from inside on a bright day, and from the garden at the roof edge. A handful of signs, appearing together, say more than any one of them.
How do I know if the sheets have had their day?
Look for cloudy or yellow sheets that no longer let light through clearly. Look for cracks, especially near fixings. Look for drips or damp marks along the glazing bars, caps that have lifted, and green or grey growth trapped inside the cells. Stand inside on a sunny afternoon too: a roof that throws a patchy, dim light into the room is telling you the plastic has aged. Any single sign can be mended. A run of them across several sheets points to a roof that has used up most of its life.
One cracked sheet in an otherwise clear roof is a small repair, and our answer on replacing individual roof panels shows how it is done. When the sheets are discoloured everywhere and the seals have perished, replacing single panels means paying twice to patch a roof that is already finished.
Deciding, and what the next roof costs
At the end of its life the roof can be replaced with new polycarbonate, with glass or with a solid tiled roof, and the frame decides what is possible. Our guide to repairing or replacing a conservatory roof sets out how age and condition tip the balance.
What does a replacement roof cost?
As typical UK ranges, MyJobQuote gives £3,200 to £6,000 for conservatory roof replacement (Oct 2026) and The Eco Experts £2,300 to £6,000. Roof area, the covering chosen, the state of the frame and how easily we can reach the eaves set where you land.
Our survey comes first. We note the condition of each sheet, bar and seal, you see pictures of them, and the price in writing afterwards is one total for the covering you pick. An inside picture of your worst sheet, with one of the eaves, tells us whether to expect a repair or a new roof before anybody climbs a ladder. Our conservatory roofs page covers the options side by side.
More on how long the sheets last
Will cleaning the roof make the sheets last longer?
Cleaning removes the moss and algae that hold water against the edges, which can slow wear at the seals and caps. It cannot restore sheets that have yellowed or turned brittle in the sun. Avoid harsh scrapers and strong chemicals on the surface, as scratches can make crazing start sooner.
Is a roof older than 15 years certain to be failing?
No. The published figures are typical, and a well-made sheet that was fitted properly and looked after can run beyond them. Age is the reason to inspect it, not proof of failure. Check for cloudiness, cracks, lifted caps and damp at the bars, then decide on what you find.
The full picture: Conservatory roofs in Taunton · More short answers