South Pasadena's housing stock is genuinely old, and that is the defining fact. Craftsman houses with original detailing, raised foundations, plaster walls and plumbing that has been patched across several eras.
Old materials change the response. Plaster and lath does not behave like drywall when it gets wet, and original wood flooring is worth saving rather than replacing, which means drying it properly rather than quickly.
What goes wrong in South Pasadena homes
Supply failures in walls are common because so much of the pipe is old, and the wall cavities are deeper and less accessible than modern construction.
Under-floor space is the other. A raised foundation means a crawl area, and a leak that runs into it can go unnoticed for a long time while it works on the joists and the subfloor above.
Can original hardwood be saved after a leak?
Frequently yes, if drying starts quickly and is done properly rather than fast. Cupped boards often flatten as they dry. Forcing heat at them is what causes permanent damage.
How is plaster different from drywall when it is wet?
It holds more water, dries more slowly and is worth preserving on a period house. It also hides moisture better, so meter readings matter more than what the surface looks like.