Cleaning a plastic conservatory roof

[Binky]

What is the best way of cleaning mildew (green) off of a plastic conservatory roof?

[WendyS]

You may have to be quite careful as the plastic may have become very brittle over the years and crack or split if too much pressure is put on it. If you have a really soft (indoors) domestic broom, scrub the roof gently with warm soapy water. such as Fairy Liquid). You could possibly add some anti mildew domestic cleaner in the water. However, if your roof drains into a gutter which then drains into a water butt which you use for watering plants, you will have to settle for plain warm water only and gentle scrubbing. If you use soapy water, hose it down with plain water to rinse (if you're not in a hosepipe ban area).

[buildersmate]

Polycarbonate doesn't tend to get brittle with times - it does scratch easily so, agreed, best that you use a soft brush plus water.