In water damage restoration, one of the most common sources of friction between restorers and our insurance partners is validating the equipment scope. Ambiguity over the right number of air movers can lead to disputes, processing delays, and adjuster pushback. These delays are costly. When mitigation is postponed, the risk of secondary damage and mould growth escalates, turning a manageable water claim into a complex and expensive remediation project.
This landscape is now changing. The recent publication of the AS-IICRC S500:2025 standard provides a new, nationally recognised benchmark for water damage restoration in Australia. This standard is being supported by major insurers and is shifting the industry away from “ad hoc” scoping toward a clear, data-driven framework.
As an IICRC Certified Firm, we are committed to this new standard of transparency and professionalism. To support our partners, we have launched a new tool: The TDR IICRC Air Mover Calculator.
The Complexity of the Standard of Care
Determining the correct number of air movers isn’t guesswork; it’s a multi-variable calculation based on the IICRC S500 Standard of Care. This is the industry’s gold standard for ensuring a property is dried scientifically, preventing microbial growth.
The formula is more complex than many realise, requiring a room-by-room calculation that includes:
- One air mover as a base for each affected room.
- One additional air mover for every 50-70 square feet of wet floor.
- One additional air mover for every 100-150 square feet of wet wall and ceiling (above 2 feet).
- One additional air mover for each structural inset or offset over 18 inches (like closets or alcoves).
Failing to account for all these variables is the primary cause of under-equipped jobs, failed drying, and costly secondary damage.
A Tool for Transparency and Faster Approvals
Our new calculator automates this complex IICRC formula. For our insurance and loss-adjusting partners, it provides an immediate, objective, and verifiable way to validate a restoration scope.
By aligning on the correct scope from Day 1, we get mitigation underway faster, prevent claim escalation, and ensure a better outcome for the policyholder. Ultimately, this helps us achieve our shared goal: minimising the total claim cost.
How many rooms are affected?
Count every room that has water damage. Each room automatically gets one air mover as a starting point.
What are the wet floor areas?
Measure the wet floor area in each room (in square metres). This includes floors and lower walls up to about 60cm high - but only enter the floor area, not the walls.
Any wet walls or ceilings above 60cm?
If water has reached walls above 60cm from the floor, or the ceiling, enter those areas here. If not, leave as 0 and skip ahead.
Are there any wall insets or offsets?
Count any nooks, alcoves, or bump-outs in the walls that are deeper than 45cm. Each one needs an extra air mover to dry properly. If there are none, leave as 0.
IICRC S500 Air Mover Calculation
This calculator follows the IICRC (Institute of Inspection, Cleaning and Restoration Certification) standard worksheet for determining air mover requirements.
Step 1: Base Count
Install 1 air mover per affected room. This is added to both the high and low range.
Step 2: Floor Areas
Add 1 air mover for every 4.5m² to 6.5m² of wet floor. This includes lower walls up to ~60cm.
Low range = floor m² ÷ 6.5 (rounded up)High range = floor m² ÷ 4.5 (rounded up)
Step 3: Walls & Ceilings Above 60cm
Add 1 air mover for every 9.3m² to 14m² of wet wall/ceiling area above 60cm.
Low range = wall/ceiling m² ÷ 14 (rounded up)High range = wall/ceiling m² ÷ 9.3 (rounded up)
Step 4: Insets & Offsets
Add 1 air mover for each wall inset or offset greater than 45cm. Added to both ranges.
Lower Walls & Limited Flooring
Use this only when water has primarily affected lower walls and limited flooring (less than 60cm of water migration into the room). This replaces the main calculation - don't use both for the same room.
