Two Suspects Under Every Slab

When these foundations were poured, copper supply lines went into the ground alongside cast iron drain, waste, and vent piping, the standard of the era, governed then and now by the Cast Iron Soil Pipe Institute, the industry’s authority on that system class for over 75 years. Sixty-some years later, both systems are at the age where failures cluster, and they fail differently: the supply sprays under pressure and bills you for every gallon, while the drains leak only when fixtures run, quietly feeding the soil beneath the foundation.

Misdiagnosing one for the other means opening concrete over the wrong pipe. These are conventional rebar slabs, so the constraint on repair is not steel tendons the way it is in newer cities; the constraint is age, and age answers most of the repair questions before the saw does.