Drying After Floods: Professional NZ Restoration Guide

It’s important to understand the basics when it comes to water restoration/remediation after a flood event…

Responding to drying after floods requires immediate action to mitigate secondary damage such as structural rot and mould growth. This guide outlines the professional structural drying process in accordance with NZ health and safety and IICRC S500 standards.

Remember: Complex water damage that involves multiple floors, wall interiors, pre-existing mould, or Category 3 (sewage or otherwise contaminated) flood water should only be tackled by IICRC-certified water damage professionals.

Critical First Steps for Flood Water Damage Restoration

Stop the water source!
Identify and eliminate safety hazards (eg, electrical and contamination issues), put on gloves and boots, and install wet floor signs nearby. Protect furniture from water damage to the extent possible.
Install an initial Dri-Eaz HEPA air scrubber or DryTrak HEPA Air Scrubber to help protect workers and others in the area

Classifying Water Types (Category 1, 2, and 3)

Ask: Is the water clean? If so, proceed! If not, call a certified restoration professional.
Determine how far the water has spread, using a Hydrosensor or Moisture meter.
Remove standing water from floors and carpets using HVE 3000 Flood Pumper and or an Extraction Tool.

Selecting the Right Structural Drying Equipment

Place dehumidifiers, airmovers and additional air scrubbers, matching the size, type and quantity to the size of the affected wet area (see formulas below).
Monitor drying progress until as dry as similar materials in nearby areas unaffected by the flood, using the Hydrosensor and moisture meter.
Make sure that DryTrak Mini LGR and Dri-Eaz dehumidifiers display positive drying trends – ie, that the “GPP” and the humidity levels on the drying trend graph are decreasing after the second day. If not, call a restoration professional ASAP.

Water Category	Source Example	Remediation Strategy
Category 1 (Clean)	Broken pipe, sink overflow	Dry in place; salvage most materials.
Category 2 (Grey)	Dishwasher/Washing machine	Sanitize; remove underlay; dry structures.
Category 3 (Black)	Sewage, Rising Flood Water	Non-porous only; remove all porous materials.
Special Hazard	Regulated materials (Asbestos)	Stop work; specialized abatement required.

The Right Equipment AND the Right Process

Fast drying to prevent mould growth and other damage only happens with commercial drying equipment. You can trust that DryTrak Axial Fans, Dehumidifiers, Airmovers, & Air Scrubbers OR Dri-Eaz dehumidifiers, airmovers and air scrubbers are the correct choice for efficient drying.

Pro-Tip: The Initial Dehumidification Formula (IICRC S500)

To calculate the number of LGR dehumidifiers needed for an initial “Simple” (Class 1) water loss:

Formula: (Cubic Metres ÷ 100) = Number of large LGR units required.
Example: For a 300m³ area, you should deploy 3 units (like the DryTrak Mini LGR) to effectively manage the initial moisture spike.

Whether you need quick tips or advanced water damage restoration education, the trained staff at Cleaning Systems are available by email or Freephone (NZ) 0800 100 117.