[andyjm1]

Cleaned a large conservatory roof today but part of it would not come clean. Part of the upvc was badly stained near the back guttering. The guttering had loads of crap in it, even an old slipper! The guy seemed to think I should have been able to clean it but despite repeated spraying and scrubbing it, nothing would shift the marks. My guess is the staining has been caused by the guttering constantly overflowing. The surface of the upvc where the marks are was slightly textured and bubbly, a bit like it had been melted.
Anyone ever come across this type of thing before? Is it water damage as I thought?

It's a shame because the con. is only 7 years old and cost £27,000.

[LQQK]

Looks like mineral deposit, which is highly likely if the gutter had a slipper in it.

[richard jagger]

I think its just neglect long term ash him how often he has it cleaned. Some custys think it good value to leave it for years. I have two customers living in the same street. Lots of building going on in the area. The one has his house and conny down every month with a big clean every 6 months on the conny roof. The other said to me he will wait till all the building was completed. Then call me because some family were coming around The same happened could not get the stains clean. What was dirt in now a stain ,What a ass hole.

[andyjm1]

He says he cleaned it himself yearly but couldn't reach the back, so this part was probably never cleaned in 7 years.
I suppose it shows what can happen if you try and save a few quid instead of leaving it to the professionals 

[Dave Willis]

Did you try  upvc cream cleaner?

[andyjm1]

Did you try  upvc cream cleaner?

I didn't, it's not something I carry but I might get some in case the same thing happens again.

[Dave Willis]

99% sure that would shift it in no time. Squirt it on an old brush head and scrub it off if you don't fancy climbing on the roof.

[john tomkins]

Don't know if cream cleaner would be strong enough but upvc solvent cleaner should clean it no probs