Just after a bit of advice from people who do their own upstairs windows.
I have just purchased a roof cleaning accessory for my Nilfisk pressure washer. The max length is 4.2m, and seems fine. It is also suitable for windows.
My local tap water is moderately hard, to the extent that I need to pay attention to the shower screen regularly. I do not want that on my upstairs windows, and I do not have a water softening system in the house (can get one if needed, perhaps, when I extend my utility room).
I will, however, have a rainwater storage setup for watering the container plants.
Q: Is this rainwater suitable for window washing, without leaving any noticeable residue on the windows?
Thanks for any thoughts.
Ferdinand