A dirty conservatory roof, whether polycarbonate or glass, reduces the light entering the space, looks unsightly, and can harbour moss and algae that accelerate surface deterioration. Regular cleaning is straightforward if approached with the right tools and method.

Safety First

Never walk on a conservatory roof. Polycarbonate and glass roofs are not designed to take the weight of a person and will crack or shatter, causing serious injury. All cleaning must be done either from the ground using extension poles, from a ladder leaning against the conservatory structure, or from a safe raised platform adjacent to the roof. A telescopic cleaning pole with appropriate attachments is the safest and most practical solution for most homeowners.

Equipment

A telescopic lance or water-fed pole that can reach the full extent of the roof is the essential tool. Window cleaning extension poles with brush attachments are widely available and can reach most standard conservatory roofs from the ground or from a short ladder. A hose connection for rinsing completes the setup. For polycarbonate roofs, a soft-bristle brush is essential to avoid scratching the surface; glass roofs can tolerate a slightly stiffer brush but should not be cleaned with abrasive materials.

Cleaning Products

A diluted conservatory or patio cleaning solution applied with the brush loosens algae, moss, bird droppings, and general grime. Purpose-made conservatory roof cleaners contain biocides that kill biological growth. Alternatively, a diluted solution of household bleach and water applied and left to dwell for 20 to 30 minutes is effective against algae and moss before scrubbing. Rinse thoroughly after any chemical treatment to prevent residue damaging the sealant strips or aluminium framework.

Cleaning Sequence

Start at the ridge and work downward, so that rinsed water and dislodged debris fall onto uncleaned areas below rather than back onto clean sections. Apply cleaning solution section by section, scrub, and rinse before moving to the next section. Work in a systematic left-to-right or ridge-to-eaves pattern. Ensure the cleaning solution and rinse water drains away from the house rather than toward it to avoid water ingress around door and window frames.

Gutters and Joints

Cleaning the conservatory roof often dislodges debris that accumulates in the gutters. Clean out the gutters at the same time and check that they are flowing freely to the downpipe. Inspect the sealant joints around the roof sections and between the roof and the frame for any splits or gaps that could allow water ingress, and re-seal any defective joints with a compatible sealant.

Summary

Conservatory roofs must be cleaned from the ground or a safe platform using extension poles; walking on the roof is dangerous. Use a soft brush, diluted conservatory cleaner or bleach solution, and rinse thoroughly. Work ridge to eaves in a systematic sequence. Apply a post-clean protector to inhibit regrowth. Check gutters and sealant joints at the same time.