we have a few different things as far as damage waivers and prevention. We will mark the heads for the customer at our normal irrigation service rate of $125-150 per man hour. We run a remote, so that lets us get speed up the process. By us marking the heads we are taking responsibility that we wont hit one. Any damage caused beyond our control will be repaired by us at our service rate with our normal markup aswel. Often people will mark the heads themselves which is no problem, but more time than not they usually miss a head or two, especially when they have spray heads in the edge of the lawn that are for a plant bed zone. A damage waiver is crucial as it is not uncomon to find a pice of pipe that is barely 1" deep because it had to go over an obstacle.
Why do people not respect us as they do other tradesmen? Because every Tom, Dick, and Harry doesn't think he can be a plumber or electrician!