Normally, it takes 24 to 72 hours for a house to dry out after a flood. However, you can speed up the drying process by renting or buying industrial-size drying fans, dehumidifiers, sump pumps, and wet/dry vacuums. In addition, environmental factors will likely influence how quickly your house dries out. If you live in an area of high humidity, for example, it means your house will take longer to dry.