Commercial Flat Roof Cleaning
Membrane roofs cleaned to the system manufacturer's own procedure.
A commercial flat roof is cleaned for a different reason than a house is. Membrane roofs are often specified as cool roofs, and a membrane that has gone dark stops reflecting. The performance the building was designed around degrades quietly, because nobody goes up there to see it.
The part that matters most is not on the roof. Membrane systems carry manufacturer warranties measured in decades, and those warranties specify how the membrane may be cleaned and with what. The wrong method does not only risk damage — it can end the warranty on the most expensive surface of the building. So the system's own procedure gets read before the work gets quoted, and if it calls for something we cannot do, we say so rather than work around it.
That is the first thing your local owner will ask for: what membrane is up there, and who made it. The building's roofing file usually has both. If it doesn't, that is a conversation to have before anyone gets on the roof rather than after.