Andy do you not find this leaves scratches any way. I know this method would definitely not work for me in my situation.
Toughened glass, if not tempered and cleaned properly during the tempering process in the factory leaves tiny particles of debris on the surface. Therefore when you rub with a scraper will carry the debris over and scratch the surface..
You can hear the difference of the scraper over the two different surfaces of glass.
Nope never scratched the glass EVER and we have done loads of windows this way.
With regard to the question ablot scope of works, the scope of works from our bulider just say clean windows, remove cement, plaster and any stickers, we spoke to the site manager and spoke to the head office but a sticker is a sticker is all they said.
We also had a problem with hinges, scope of works says remove excess paint off of all fittings, we got caught out on hinges that had slight and i mean slight paint on them so we had to check all hinges on the houses, and the bigger houses on this particular site are 2500sqft and have nearly 100 hinges a lot of work which we worked out averages at nearly 2 hours per plot which we hadnt accounted for
we are still in talks about this as to be honest its a pee take which the painters shoud sort out!!!!
I think your always gonna be taken for a ride buy the buliders it is hard work but it does even out now and again in your favour