Drying Water Damaged Ceilings
Upstairs water damage from plumbing problems and attic water damage from leaking roofs will flow through the ceiling. Moisture metering and infrared cameras will reveal which areas of the ceiling are affected. It is common to mark out wet areas and then cut out vent holes through which wet insulation is removed. Dry air is then blown into the ceiling cavity. Moisture and equipment operation is monitored daily and recorded until the ceiling is determined to be completely dry.
This illustrates why professional water extraction needs to begin as soon as possible after a floor has been flooded. The more extensive measures are usually only necessary when standing water has been in contact with walls for a substantial period. Initially clean water left standing for more than 24-48 hours can deteriorate into unclean (category 2/category 3) water which may pose health risks. This is also true of water that has been absorbed but not removed from carpets and walls.
The above is not intended to be a do it yourself guide. Operating electrical equipment in a wet environment is inherently dangerous. Failure to completely dry out and disinfect all affected structures can cause secondary damage such as mold and dry rot that weakens critical support. Material that appears dry can often retain hidden moisture that supports the growth of mold.