Polycarbonate roof lifespan
How long does a polycarbonate conservatory roof last?
The short answer
Around 10 to 15 years is the typical range for a polycarbonate conservatory roof. HomeBuilding gives a typical lifespan of 10 years, and the Eco Experts say 10 to 15 years. That is a guide, not a promise. Sun exposure, the quality of the sheets and seals, how the roof has been cleaned and how well the installation was done can move a roof towards either end of the range.
How long polycarbonate sheets tend to last, the signs that a roof is wearing out, and a way to weigh up patching against starting again.
What the published guides say
Two published guides give a similar picture. HomeBuilding, in April 2024, puts the typical lifespan of a polycarbonate conservatory roof at 10 years. The Eco Experts, updated later that month, say 10 to 15 years. A fair planning figure is therefore around 10 to 15 years, with some roofs falling outside it either way.
Be clear what the number means. A lifespan describes how long the sheets typically stay clear, watertight and sound. It is not a warranty, and a roof that reaches 12 years is not a failure any more than one that reaches 18 is a bargain. Plenty of roofs simply keep going until a leak or a crack forces a decision.
Polycarbonate is chosen because it is light, so the frame carries little load, and it is cheaper than glass to fit. The trade-off is that the sheets are softer and age faster than glass in the same position. Our comparison of glass and polycarbonate roofs sets the two side by side.
Signs the sheets are reaching the end
You can usually see age before you feel it. Look for sheets that have turned yellow or cloudy, a surface that looks scratched, dull or chalky, and fine cracks near fixings or at the edges. Hairline cracks matter because rain gets into them and the sheet can split further.
Check between the flutes (the hollow channels that run the length of a multiwall sheet) for green or black growth. It usually means the end sealing has failed and water, dust and spores have crept inside, and it cannot be cleaned out from above.
Then look at the joints. Glazing bar seals that have shrunk, caps that have lifted and gaps at the ridge and eaves let in water long before the sheets themselves wear out. A stain on the ceiling line or drips after heavy rain is the usual sign. Our guide to a leaking conservatory roof explains how to trace the source.
What shortens, and what protects, the sheets
Sun and temperature swings work on any plastic, and a south-facing roof gets more of both than a shaded one. How the sheets are sealed at the ends and fixed to the bars decides how well they cope. A sheet fitted without proper end tape can fill with moisture within a few seasons, however good the material.
Cleaning matters too. Gentle washing with a soft brush and mild soap is the usual advice, and harsh abrasives, strong solvents and pressure washers can scratch or craze a surface that is meant to stay clear. Overhanging branches drop leaves and sap that stain and hold damp against the sheets.
Movement is the other cause. A conservatory frame expands and contracts, and a roof fixed too tight can crack at the screws. That is why the fitting counts for as much as the sheet itself, and why two identical roofs can look very different after the same number of years. Cleaning with care, and keeping branches cut back, costs little and slows that wear.
Repair, reseal or replace
Not every tired polycarbonate roof needs a new one. If the sheets are clear and sound and the trouble is perished seals or a loose glazing bar cap, the smallest fix is a reseal or a new strip of tape. A single cracked panel can often be swapped for one that matches, and our answer on how to replace a conservatory roof panel covers when that works.
Replacement makes sense when the sheets are yellowed or cloudy throughout, when several panels have cracked, or when water is inside many flutes. Patching a roof that is failing everywhere only pays for the same scaffold twice.
When the old roof comes off, the frame also needs a look. Rot, loose bars and a sagging ridge cannot be fixed by new sheets alone. The survey includes the frame, and we say whether it can accept a covering of equal weight or something heavier.
Choosing what comes next
A replacement does not have to be polycarbonate again. Glass is heavier, so the frame has to be fit to bear it, and a lightweight solid roof is a different build again. A solid roof needs Building Regulations approval, and the Planning Portal ties that to structure, energy performance and ventilation.
Compare the options on what you use the room for. A room kept for plants and summer evenings has different needs from a home office, and a roof that suits one can disappoint in the other. Think about winter use as well as July. Our survey takes in the frame, the base and the sheet details, and the photographs of what turns up explain the reasoning behind our advice.
A written quote follows, giving one figure for the roof we advise. For the broader picture, see our conservatory roof replacement page.
Related questions
Polycarbonate roof queries
Does a longer product warranty mean the sheets last longer?
Not necessarily. A warranty says what the supplier will fix, and for how long, under set conditions. A lifespan is how long a roof typically performs. Read what the warranty excludes, such as yellowing, and remember that installation quality decides how well any sheet performs.
Can cleaning extend the life of a tired roof?
It helps with surface grime and algae on the outside and keeps the seals visible. It cannot reverse yellowing or clear moisture trapped inside the flutes. Use a soft brush and mild soap, avoid abrasive pads, and have failed end seals dealt with by a roofer.