Boy so many reply's, sorry just logged on. To answer some questions, £20000 to replace all the windows. scratches on the inside windows. Only used scraper with brand new blade on small parts of the window, not the whole window. Yes window was wet. We sprayed the window with a cement softener first, then got to work on the frames, after 10 mins we thoroughly washed the window squeegeed off, and then if there was any little particles left used the scraper . The fault I am convinced is with the window itself. Going down tomorrow with the company who we subbed off who are totally behind us. Will keep you all updated. Regards, Mike