Water expands as it freezes, and the pressure splits copper and bursts fittings. The leak often starts when the ice thaws, sometimes days after the cold snap, inside a wall, under a sink or above a ceiling where nobody sees it at first.
Where pipes freeze in older homes
January nights in the single digits find the weak spots fast. Older houses here tend to run supply pipe where the cold reaches it:
- Kitchen and bath pipes on outside walls, especially behind cabinets
- Enclosed porches and additions built over open crawl spaces
- Basement corners near sill plates, bulkhead doors and broken windows
- Pipes to outside spigots and baseboard heating loops in unused rooms



