Short answer
Clean a conservatory roof from the ground using an extendable soft brush or a water-fed pole: rinse off loose dirt, wash with warm water and a mild detergent, then rinse thoroughly. Never climb onto a conservatory roof or lean a ladder on it, as the glazing and frame are not designed to take a person's weight. Avoid abrasive pads, harsh chemicals and high pressure.
Safety first: never climb on the roof
A conservatory roof is not built to be walked on, knelt on or leaned against. Glass and polycarbonate panels can crack or give way, and glazing bars can bend. Do not stand on the roof, do not rest a ladder against it, and do not lean out over it from an upstairs window.
All of the methods in this guide work from the ground, or from a sturdy step on firm ground at the edge of the conservatory. If you cannot reach part of the roof that way, leave it, or ask a professional.
Glass or polycarbonate?
Find out what your roof is made of before you clean it. Glass roofs are harder-wearing and easier to get clear. Polycarbonate roofs are lighter plastic sheets, often with a ridged or multi-wall profile; they scratch more easily and can be damaged by solvents and some cleaning products.
Some glass roofs have a self-cleaning coating. These usually need gentle cleaning only, with no abrasive products, so check the manufacturer's care guidance. The same applies to tinted or coated polycarbonate.
What you will need
An extendable pole with a soft brush head, a garden hose with a gentle spray setting, a bucket of warm water with a little mild detergent, and soft cloths or a sponge for the frames. Avoid stiff brushes, scourers, abrasive cream cleaners, solvents and pressure washers, which can scratch the roof, damage seals or force water into joints.
How to clean the outside of a conservatory roof
- Choose a dull, calm day so the roof does not dry too quickly in sunshine and leave smears.
- Clear the conservatory gutters first if you can do so safely from the ground, so dirty water can drain away.
- Gently rinse the roof with the hose to remove loose dirt and soften dried-on marks.
- Using the soft brush on the extendable pole, wash the roof with warm soapy water, working from the top down and along the ridges on polycarbonate.
- Rinse thoroughly with clean water until no suds remain.
- Wipe the frames, sills and glazing bars you can reach with a soft cloth.
- Check the result once dry and repeat any patches that still look dull.
Moss, algae and bird droppings
Green algae and moss tend to grow where leaves collect in the glazing bars and gutters. Soak the area, brush it gently and rinse. Bird droppings should be softened with water before brushing, rather than scraped off, which can scratch the surface.
If you want to use a stronger cleaner on green growth, choose one suitable for your roof material, follow the label exactly, test it on a small area, protect plants below and never mix products.
Cleaning the inside of the roof
The inside collects dust, cobwebs and condensation marks. Use a soft mop or a microfibre cloth on an extendable handle, slightly damp, and work in sections. A stable stepladder on a level floor is fine for reaching low points, but do not stand on furniture or overreach. Ventilating the room helps reduce condensation marks.
Keeping it clean
A light rinse and brush now and then is much easier than a deep clean once dirt has built up. Trim back trees that drop leaves on the roof, and keep the conservatory gutters clear so water and debris do not sit along the bottom edge. The frames and fascias around your home can be cleaned in a similar way, which our guide to cleaning uPVC explains.
When to call a professional
Call a professional if you cannot reach the whole roof safely from the ground, if the roof is heavily stained or green, or if you are worried about damaging a coated or polycarbonate roof. It is also worth getting the gutters cleared at the same time.
We clean conservatory windows and uPVC frames gently with water-fed poles and soft brushes, using pure water for the exterior work, and conservatory gutters can be cleared so water drains properly. Internal glass and frames can be cleaned too, by agreement.
Rather have it done for you?
Conservatory glass, frames and gutters cleaned inside and out. Family-run by Jason and Lucas Prior, covering south Essex.
Frequently asked questions
Can I go on my conservatory roof to clean it?
No. Conservatory roofs are not designed to take a person's weight, and panels or glazing bars can crack or give way. Clean from the ground with an extendable soft brush or water-fed pole.
Can I pressure wash a conservatory roof?
It is best avoided. High pressure can damage seals, force water into joints and mark polycarbonate. Warm soapy water, a soft brush and a gentle rinse are safer.
What should I not use on a polycarbonate roof?
Avoid abrasive pads, stiff brushes, solvents and harsh chemicals, which can scratch or cloud the plastic. Check the manufacturer's guidance and use a mild detergent.
Related guides
- How to clean uPVC: getting white uPVC frames, doors, fascias and soffits clean without scratching or dulling the surface.