Quick answer: Never stand or kneel on a conservatory roof — the glazing and frames are not designed to take a person's weight. Clean roof panels from a stepladder positioned outside the conservatory using a telescopic pole and soft brush, or use a water-fed pole from the ground. For the vertical glass — side panels and doors — a robot window cleaner does the work automatically. Twice a year keeps algae from taking hold.
You built the conservatory for the light. That was the whole point — coffee in the sun without the weather, the garden view in January.
Then British weather got to work. A film of green algae creeping up from the gutter line. Lichen dots. That grey traffic-and-rain haze. And now the sunniest room in the house has a permanent Instagram filter called "Gloom."
Here's how to get the light back without ending up on 24 Hours in A&E.
First, the rule that overrides everything
Conservatory roofs are not load-bearing. Not the glass, not the polycarbonate, not the glazing bars. People are seriously injured every year in the UK falling through roofs they thought would hold them — fragile roofing is one of the HSE's most-flagged fall hazards for a reason. However solid it looks, the answer to "can I just climb up quickly?" is no. Always work from beside or below the roof, never on it.
Cleaning the roof panels (the green bit)
What you'll need: a telescopic cleaning pole with a soft brush head, a hose, and either conservatory cleaner or diluted washing-up liquid. For algae, a dedicated glass-safe algae remover saves a lot of scrubbing.
- Rinse first. Hose the roof down to lift loose debris — scrubbing dry grit is how glass gets scratched.
- Work top to bottom, panel by panel. Extend the pole and brush along the fall of the roof so dirty water runs off rather than across cleaned panels.
- Do the glazing bars and finials too. Algae anchors in the frame joints and re-seeds the glass if you leave it.
- Rinse again and let it air dry. If your water is hard, a final rinse helps; purified-water pole systems dry spot-free.
- Clear the gutters while you're there. Blocked conservatory gutters overflow down the side glass and undo your work in one rainy afternoon.
Twice a year — spring and autumn — stops the green film ever getting established. (More on ideal frequency here.)
Cleaning the side glass and doors — the easy win
The vertical glass is 60% of a conservatory's cleaning load: full-height panels, French or bifold doors, inside and outside faces. It's also, conveniently, exactly the kind of large flat pane a robot window cleaner is built for.
Attach the CleanBot R1 to a panel and it grips with 6,500Pa of suction, mists the glass, and works the whole pane in systematic N/Z passes — edges included, which is where conservatory panels always stay grubby when you hand-wash them. Move it panel to panel while you do the roof brushing, and the whole conservatory gets done in one session — you handling the one part a robot can't reach, the robot handling the acreage.
Inside faces too: conservatory interiors fog up with condensation residue and dog-nose art, and running the robot indoors is a press-and-walk-away job.
What about hiring a conservatory cleaning service?
A professional conservatory clean in the UK typically runs £60–£150 per visit depending on size, roof included. Perfectly good option for the roof twice a year. But if you're paying that four times a year mostly for the glass — the sides and doors — you're renting labour for a job a £173 machine does on demand. Do the roof yourself or pay for it twice yearly, and let the robot own the glass in between.
Keep it cleaner for longer
- Trim back overhanging branches — sap, blossom and bird traffic are the roof's main polluters
- Treat algae, don't just wipe it — wiping spreads spores; an algae treatment kills the regrowth
- Rinse the roof with the hose monthly in autumn — 5 minutes that saves the spring deep-clean
- Keep gutters clear — most "dirty side glass" is actually gutter overflow stripes
FAQ
Can you walk on a conservatory roof to clean it?
No. Conservatory glazing and frames are not designed to carry a person's weight, and falls through fragile roofing cause serious injuries every year. Clean from a pole beside or below the roof instead.
How do I get green algae off my conservatory roof?
Rinse first, apply a glass-safe algae remover or conservatory cleaner, brush with a soft telescopic brush, and rinse off. Treat the glazing bars too, or the algae regrows from the joints.
How often should conservatory windows be cleaned?
Roof panels: at least twice a year (spring and autumn). Vertical glass: monthly if you want the room to stay bright — easy if a robot does it.
Can a robot window cleaner clean a conservatory roof?
Robots are designed for vertical or near-vertical glass, so they're ideal for conservatory side panels and doors. For the shallow-pitch roof, use a telescopic pole from outside.
Let the robot take the glass while you take the roof: CleanBot R1 — £173, 24-month warranty, free UK delivery over £75.