Slab leaks occur when the pipes in your foundation become corroded. It can also happen if a pipe bursts. ... When slab leaks happen, it's because the pipes in your foundation have pinhole leaks. These leaks are caused by corrosion, which can happen as a result of the home settling on the foundation. You will need to contact a leak detection company to determine where the leak is coming from. Once you know where the leak is coming from, you can call you local plumber to do the repairs.