In older homes, the plumbing does not last forever. Depending on water quality, copper pipes usually survive for 30-40 years. Without proper grounding of copper pipes, leaks caused by electrolysis may occur much quicker. This will be much more common in a pier and beam house or even in a slab when some types of pvc or plastic is used though the soil and metal pipes are only used above ground. Tubs, showers, sinks, dishwashers, clothes washers and garbage disposals can all develop slow leaks.
