Even after cleaning thousands of windows on builders cleans, we were caught out today!!
What would normally have taken 2 of us about 3 hours ended up taking 8 hours!! The tapes on the frames took an age to get off, and left adhesive on the frames, which we got off using thinners, it was a pig of a job.
We noticed soon after starting that the tape had a warning printed which read 'Warning, remove after 5 days', it had been on there for a few months!
The polythene covering the sills had the message, 'remove immediatley after installation'. It came off in little pieces, a right job.
My advice would be to give the glass and frames a thorough inspection next time !!