Did a large conservatory today....top really minging with moss etc. Gave it a good scrubbing with a non-abrasive pad and because the sun was drying it faster than I could blade off i took her garden hose and gave it a good rinse.
I told custy that it would dry spotty but that the next big downpour would clear it...I'm thinking of the wfp guys saying as rain water is pure.
Have i told her a load of old cobblers?
The thing is simon, I notice you live in the London area, is the TDS high in London? I think it is going by other posts, if thats the case you will leave it spotty, I live in the south west and I have cleaned con roofs with tap water and they dry ok, I don't do it now I use pure, if your water is hard then it will get spotty, pop back and have a look, you may just be lucky and gotten away with it? Hope you have.