Question: How long will the paint marks you put down on the ground last?
Answer:
One of the question we seem to get asked all the time when we are out doing underground service locating is, “How long will the paint marks last on the ground?”
Well the answer is, it will depend on the surface that we are marking, the vehicle and pedestrian traffic, and of course the weather.
If it is a concrete footpath then it will last longer than say a gravel road.
If it is the side along the nature strip and we put our paint marks on the grass and then the grass gets cut a week later, then don’t expect the marks to still be there afterwards.
If it is raining then it is really hard to mark the ground. Let me give you an example, let’s say it is raining and we are locating something that is running along the road, we will put the marks down on the road so that we can show you (the client) where the underground service is, but, if it is raining the even though the road is bitumen you still shouldn’t expect the mark to be there the following day – and unfortunately sometimes they maybe not even be there the following hour if it is heavy rain.
Generally, however, we normally give a guide of about a month for the paint marks to last on the ground.
Although there was one site that we went back to a couple of years after we had originally been there and there were still signs of the paint we put on the fence paling from when we first did the underground service locating. Admittedly we didn’t see the mark on the fence when we first arrived to site, but as I was following the optic fibre and marking it as I went I got up to the fence and went to put my normal mark on the bottom so that it lasted longer than the ones in the grass and then saw the old mark.
And yes for those of you wondering, the locator did line up with the exact spot it was last time 
**Update**
The other day we were onsite and I was trying to mark a water pipe that I had located crossing the road. It was raining but the client really needed the job done that day so we put the rain coat on and kept working. I marked the ground and the depth of the pipe. Literally less than 5 minutes later this is what it looked like.
So I thought this would be a good photo to add to this post.