Polycarbonate conservatory roof - BURNT maybe???

[SALB]

Hi - can anyone help
We had a conservatory built onto our house which actually is part of the house (2 sides are) - the roof is attached to the main wall of the back of our house - this was done approx 7-8 years ago
In the last year in the corner of the top of roof where it adjoins the main house (both sides) it has discoloured to what I can only described as black/burnt!!!! We don't think its in the middle of the polycarbonate but we cannot wipe it off on the roof. It extends about 3 feet from where it joins the lead and across the panel - there are about 8 panels and each panel has this on but it gets less and less as you go across the top. We have called out the people who did the conservatory and they are stumped as to what it is. The roof is double polycarbonate and we are pretty sure its not inside.
Has anyone encountered this before - we actually think the heat this year may have reflected on the walls of the house onto the roof - well we just can't think of anything else but HOW to remove it is the question??
Many thanks SAL

 

[Burnerman]

If polycarbonate is discoloured in any way then its only a replacement will do, unfortunately.
Very unusual for the stuff to burn in this way - there couldn't have been a chemical spill up there?
John

 

[SALB]

No definately not
the men who put it up came today and they are mistified as much as we all are!!
Thanks for your reply

 

[noseall]

Is this product light sensitive or photosensitive or light polarising?

Products like ex-foam are sunlight sensitive and darken with exposure.

 

[SALB]

I have no idea unfortunately I am not qualified to even say - the conservatory company say they haven't seen anything like it before!!

 

[s60tsy]

poly will discolour if it is fitted the wrong way round but it normally goes green all over or yellowish