[steveselvage]

I have been cleaning a house with a sloping tiled roof beneath the windows, over the last few months the customer has been asking what chemicals are in the water. When i explained that it was pure water he showed me the marks on his roof tiles.
They seem to be bleached almost white under the windows that i clean, its as if the water draining off has cleaned the colour from the tiles.Its definately the water as after i cleaned them yesterday the water drained exactly over the white bits. It looks really bad and he has asked me to wet the entire roof down every month in the hope that it will even out the discolouration.
Has anyone else seen this?

[Trevor Knight]

Can't say we have had that problem although what you say makes sense as the water will be dragging the dirt off the tiles as it runs away?

[SherwoodCleaningSe]

It makes sense.  I've noticed that if I run water from my truck in the road it will leave cleaner patches on the concrete.

But what a cheek, it's not you fault his roof was dirty in the first place, is he prepared to pay for the extra water.  I wouldn't waste water on a roof unless some one was paying for it.

Simon.

[macmac]

have to agree with simon.

tony

[brett walker]

Ive noticed this on one of my properties its removing the green off the slates it does look a bit odd but the customer hasnt said anything yet

regards

Brett

[Londoner]

The concrete in my garden where I fill my containers looks like its been pressure washed but it hasn't. Its just the spilt water thats done it.