i just go and have a look at it with the customer. you need to be able to go into their house and see what they are seeing so you can discuss it
i tell them before i go that we clean in a very specific pattern (across the top, then up and down, the across the bottom) and so if it looks like we might have caused it, we will replace the window, no question. but i do say to be honest its very unlikely that we have caused it because of the equipment, the brush, how hard it is to scratch glass etc etc.
so i say, if the marks are up and down or horizontal across the top or bottom we'll fix it. but if is circular scratches, or little scratches in a small area, then it just cant have been us
then the customer will have a look for themselves and think about it, before you come, and then when you come out they dont feel tricked or under pressure. they already know what you're going to say.
the trick is to make it a conversation that you're both working together to have a look at it to try and work out the mystery of the scratched glass.
you don't want it to be them against you, rather them and you thinking it through together so you come to the same conclusion at the same time. and in truth, that is what you are going to be doing. its not a trick, you're just walking through the decision making process with them
i take a nice clean brush head in with me to and show them how we clean.
then we talk a bit about glass being hard to scratch, i tell them we had to know for sure that we weren't scratching glass so i dipped the wet brush in sand, and soil, and gravel, and then really tried to scratch an old window of mine, to no effect (thats true, do it yourself to see so you are sure what you are saying)
then we talk a bit about light, and how you don't notice imperfections in glass unless you are looking when the light hits it at a certain angle... then we talk a bit about how even on newly installed glass the quality criteria is only if you can see an imperfection from 6 feet away...
and then the customer usually says... oh i dont think it was you was it, and i say no i dont think so. and then we leave as friends after a brief chat about the mystery of what on earth causes scratches on glass
and if it looks there's even a chance (based on the pattern of the marks) then you just say, listen i dont think we did it, but to be honest i cant say for certain so we'll have it replaced. i'll get a glazier to give you a call to arrange a replacement...
