ROOFTOP CLEANING

Hi all

I'm about to move into an apartment with a private rooftop but the floor is quite green and I think it would look much nicer if it was given a good clean.

Back home I would have rented a pressure washer but I can't find anywhere here who rents, and it seems like too big an investment to buy one as I might only be here a year or so.

Does anyone know of companies who will come and clean apartment rooftops? Or any other tips/ideas?

Thanks!

Vicki