[exterioruk]

i have got a job to clean a conservatory roof, but it has really bad algey, what is best to remove this

many thanks

[fez]

I've had terrible ones, covered in green. All I use is an applicator on a pole or a car brush, with soapy water and it usually comes off a treat. Wash down with a hose and (if you like) a final wash with GG4 and it'll be even easier next time.

A word of warning though, if it's a victorian style with spikes on the top, be careful as it's easy to knock 'em off. Go steady. If they do fall off, they just clip back on again but it's a pain to do from a distance.

[denzle]

A good strong bleach added to a bucket of water will eat the stuff, just beware of splashes to your eyes so wear some good eye protection.
Denzle