If you are wondering how to clean a conservatory roof safely, the answer is to work from the ground with a soft brush on an extendable pole and plenty of water, and never climb onto the roof or lean a ladder against it. Polycarbonate and glass need slightly different care, but the rule about not putting any weight on the roof applies to both. In December, with the days at their shortest, a clean roof makes a real difference to how much light gets into the room.
Why should you never walk on or lean a ladder against a conservatory roof?
Conservatory roofs are built to keep the weather out, not to carry a person. The glazing bars are thin, polycarbonate sheets flex and split under a knee or a foot, and glass panels can crack without warning. People do fall through conservatory roofs, and in winter the surface is slippery as well.
Leaning a ladder on the roof or its gutter is not much better. The gutters on conservatories are light and often just clipped on, so the weight of a ladder can crack them or pull the seals. If you cannot reach a section from the ground, leave it.
How to clean a conservatory roof, step by step
- Clear loose debris. Use a pole to pull leaves and twigs off the ridge and out of the valleys.
- Wet the roof and apply a mild, non-abrasive cleaner. Avoid solvents and anything not suitable for plastics.
- Brush gently from top to bottom with a soft-bristled brush. On polycarbonate, follow the direction of the flutes.
- Work moss out of the joints where sheets or glass meet the glazing bars, without forcing the seals.
- Rinse thoroughly with clean water. Pure water is best, as it dries without spots.
- Clear the conservatory gutters and check the downpipe runs freely.
- Finish with the frames and side windows, so dirty run-off does not land on glass you have already cleaned.
Polycarbonate vs glass: what is the difference?
Polycarbonate scratches easily, so no scouring pads, no stiff brushes and no pressure washer. Most older conservatories use multiwall sheets with hollow flutes. If green appears inside the flutes, the end tape or caps have failed and water has got in. Cleaning the outside will not fix that; the sheet ends need resealing or the sheets replacing.
Glass is tougher, but many glass roofs have a self-cleaning coating that abrasive products will strip. Gentle brushing and a clean rinse is all it needs.
What causes green streaks, and how often should it be cleaned?
Green streaks are algae growing where water sits, usually along the glazing bars and at the lower edge of the roof. They are worst on north-facing roofs, under trees and where moss drops off a house roof above. Bird droppings and leaves feed the growth, and blocked conservatory gutters make it worse because water backs up instead of draining.
Most conservatory roofs need cleaning once a year. Late autumn into winter is a good time, once the leaves are down and before the green really takes hold. Shaded roofs may need a second clean in spring. Ideally it fits in with your regular window cleaning, so the whole conservatory looks right at the same time.
Frequently asked questions
Can I pressure wash my conservatory roof?
We would not recommend it. High pressure can force water past the seals, damage polycarbonate and lift the tape on the sheet ends. A soft brush and plenty of water does the job without the risk.
Can a conservatory roof be cleaned in winter?
Yes, on days without frost or ice. Winter is when a clean roof makes the most difference, because every bit of daylight counts.
How often should a conservatory roof be cleaned?
Once a year suits most homes. Roofs under trees or facing north may need cleaning twice a year to keep moss and algae under control.
How CamClean can help
We offer conservatory roof cleaning in Cambridge, Cambourne and the surrounding villages from £99. If your house gutters are also full of autumn leaves, our gutter clearing starts from £129. Our staff are vetted and insured. Call 01954 783308 or contact us for a quote.
