The response window immediately following water damage significantly affects both the final repair cost and the risk of secondary problems like mould growth, making fast action more important than a perfect plan. The first priority is stopping the water source, whether that means shutting off a main valve or addressing an external leak, since continued water intrusion compounds damage every additional hour. Removing standing water quickly, using pumps or wet vacuums for larger volumes, reduces how deeply water penetrates into flooring and subflooring materials. Air circulation and dehumidification should begin as soon as standing water is cleared, since damp materials left unaddressed for more than 24 to 48 hours create ideal conditions for mould growth. Professional restoration services use moisture meters to identify dampness that is not visible to the eye, which is particularly important for materials like drywall and subflooring that can retain moisture long after surfaces appear dry. Documenting damage thoroughly with photos before cleanup begins is also worth doing immediately, both for insurance purposes and for tracking the restoration process accurately.