Removing the Guesswork: TDR’s New Calculator Aligns Scopes with the AS-IICRC S500 Standard

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.

Step 1 of 5

Step 1

How many rooms are affected?

Count every room that has water damage. Each room automatically gets one air mover as a starting point.

💡 Count each separate room - including bathrooms, hallways, and closets - as its own room if it has water damage.

Step 2

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.

📏 Not sure of the area? Multiply the length by the width of the wet section. For example, a 3m x 4m wet area = 12m².

Step 3

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.

💡 This only applies to wall areas above 60cm from the floor. The lower 60cm is already covered by your floor measurement.

Step 4

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.

💡 An inset is where a wall steps inward (like a closet nook). An offset is where it steps outward (like a chimney bump-out). Only count those deeper/wider than 45cm.

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.

Note: When any calculation results in a fraction, always round up to the next whole number. In small rooms under 2.3m², one air mover may be adequate.

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.

Affected linear metres of wall Measure along the base of all affected walls.