Why does my roof leak even after the rain stops?

When a roof continues to leak even after the precipitation has stopped, it is usually due to accumulated water pooling or traveling slowly through your home's framing structure before finally finding an exit point into your living space. During a storm, heavy volumes of rainwater can pool in low spots, saturate thick layers of insulation, or fill up hollow cavities within the ceiling joists and roof decking like a reservoir. Because this trapped water must follow gravity through winding paths of least resistance, it can take hours or even days to slowly seep through drywall, plaster, or wooden beams long after the rain clouds have cleared. Additionally, melting snow and ice dams can cause delayed leaks as trapped moisture thaws during the warmer daylight hours, trickling down into the attic well after the actual snowfall event has ended, making diagnosis tricky without a thorough inspection of the attic and roof framing.