JP and Zoanas, about how much did it cost? I'm trying to decide if I should have the house re-piped or keep fixing the leaks.
My house has copper piping that is about 4" under the slab. The last two times I had leaks I used my infra-red gun to locate the hot spots, then carefully dug out the grout and lifted the tiles around the hot spot. Then I rented an electric jack hammer (bosch of course) for $50 a day and jack-hammered a big hole. I dried out the system and soldered in a new section of copper pipe. total cost was around $75 per leak and 12 hours of hard labor. of course that price included beer.
Unfortunately the problem keeps coming back in different areas so I figure all the hot water pipes (and maybe the cold too) are ready to go.
I found very small pin hole leaks in the piping I cut out with green corrosion around the pin holes. I'm told that is typical in this area.
Here's a picture of the last time:
I was lucky that time because I only had to pull up two tiles. This leak is under the bathroom, about 10 feet away.