How to Clean a Conservatory Roof Safely

Safety first: never stand on the roof

Do not climb onto a conservatory roof, kneel on the glazing bars or lean a ladder against the panels. Neither glass nor polycarbonate is built to be walked on, and glazing bars can flex or crack. Work from the ground with an extension pole, or from a ladder set on firm, level ground beside the conservatory with someone footing it. If you cannot reach safely, stop and leave it to a professional.

Avoid working in wind, in strong sun or when the roof is wet and slippery from overnight dew.

Glass or polycarbonate?

Glass roofs are smooth and fairly scratch resistant, and many modern ones have a self-cleaning coating that must not be scrubbed with abrasives. Polycarbonate roofs are lighter multiwall sheets that scratch easily and can be damaged by solvents. Green growth and dirt often build up inside the channels at the ends of polycarbonate sheets. Knowing which you have decides the products and tools you use.

What you will need

A telescopic water-fed brush or soft bristle extension brush, a bucket, a mild non-abrasive detergent such as washing up liquid, a hose and possibly a garden sprayer. A plastic scoop or gloved hand will help with the gutter. Avoid pressure washers, scouring pads, wire brushes and household bleach.

Step by step

First clear loose leaves, twigs and moss from the roof with the dry brush, working from the eaves upwards so debris falls towards you rather than into the gutter at the house wall. Next wet the roof with the hose. Mix warm water with a small amount of detergent and work it gently over each panel, one at a time, using light pressure along the length of the sheets. Rinse thoroughly with the hose, top to bottom, until no suds remain. Finally clean the frames and glazing bars with a soft cloth.

On polycarbonate, never scrub across the sheet and never use solvents. On self-cleaning glass, follow the manufacturer guidance as some detergents can affect the coating.

Do not forget the gutter at the edge

The small gutter along the front edge of a conservatory catches everything you wash off the roof. If it is not cleared at the end, the debris will block the outlet and water will overflow onto the frames and patio. Scoop it out by hand from a ladder, then flush the downpipe with the hose to check water runs freely.

Dealing with green growth

Algae and moss on the roof usually lift with a soft clean, but where growth is heavy, a conservatory-safe algae product applied at low pressure and left to dwell can help. Rinse well and keep it off plants. Growth in polycarbonate end channels is harder to reach and may need the end caps checking.

When to call a professional

Large roofs, high roofs, lean-to roofs above another roof and roofs you cannot reach safely from the ground should be left to a professional. The same goes for heavy staining, damaged sheets or seals. The conservatory cleaning roof and frames guide explains what a full professional clean includes, so that is not covered again here.