This is probably the worst conservatory roof I've ever cleaned.
Its around 35 years old, 20-25ft long, last cleaned more than 5 years ago, unusual shape roof which is higher than usual (probably about 18ft).
I reluctantly agreed to do this for a regular customer, and told them I couldn't give a firm quote as the time it would take was an unknown due to how stubborn the Lichen would be to shift.
Used a combination of Non Nonsense Degreaser, Ecover Washing Up Liquid, Cif and Dettol Mould and Mildew Remover.
Didn't take many photos but here's a few:
Before
After