I have a question. Today I got a call from the property manager of one of my largest accounts. She says that the irrigation guy said I damaged 15-20 sprinkler heads in the entrance of the subdivision with my trimmers and mowers. He explained to her how I did this. Now she thinks I should compensate them something for this. Is is possible to damage one of these with the trimmer or mower? We edge using the trimmer, not one of those hard edgers. I told that if it was properly installed that should not have happened. The funny thing is I think this irrigation guy is one who installed the system. It's probably well over ten years old. What's the life span of these heads? Just want to get a professionals opinion on this, as we do not do irrigation. Also do these things really cost $20.00 a piece plus labor?