Storm damage or long-term water entry? How a forensic consultant tells the difference

Cause, not cover

After a storm, one of the most common questions is whether water damage was caused by the storm, or by water getting in over a longer period. Policy wordings treat these differently, and how a policy applies is a matter for the insurer. The ICA’s expert reports standard says experts should not give a view on how policy terms apply.

The consultant’s job is to set out the facts that decision rests on: what happened, when, and why.

What we look for on site

Fresh storm damage and long-term water entry usually leave different signs.

Signs consistent with recent storm damage include:

• displaced, cracked or missing roof tiles or sheeting, with clean, unweathered break edges
• lifted or torn flashings and cappings
• impact marks from hail or wind-blown debris
• leaves, debris or hailstones in gutters, valleys and the roof space
• damage that lines up with the storm’s wind direction.

Signs consistent with water entry over a longer period include:

• layered staining or tide marks, from repeated wetting and drying
• timber decay, softening or fungal growth
• corrosion of fixings, brackets and sheet laps
• efflorescence or salt deposits on masonry
• swollen or delaminated sheet materials
• sealants, flashings or pointing that have failed through age.

None of these signs is conclusive on its own. The answer comes from how they fit together. Moisture readings and mapping show where water is now and how far it has spread. Inspecting from outside and inside traces the path the water has taken.

What the records show

Site evidence is then tested against records.

The Bureau of Meteorology’s Daily Weather Observations give each day’s rainfall, strongest wind gust, temperature and other readings for weather stations around Australia. They cover the current month and the previous 12 months. Older data is available through the Bureau’s Climate Data Online. The Bureau’s Severe Storms Archive records reported severe events such as damaging hail, severe wind gusts and heavy rain.

Weather records need care. The nearest station may be some distance away, and conditions at a property can differ from those recorded. The Bureau notes that many storms are never recorded in its archive, particularly where no-one sees or reports them. A good report names the stations used and how far they are from the site.

Other records help too:

• maintenance and repair history
• earlier inspection or pre-purchase reports
• dated photos taken by the owner or occupants.

Weighing it up

Often the answer isn’t one or the other. A storm can find a weakness that was already there, such as a failed flashing or a blocked gutter. Damage from both causes can sit side by side.

A good report separates them where the evidence allows. The ICA standard asks experts to say how much each cause contributed where there is more than one. The report should also say whether the opinion is tentative or firm, and what further information could change it.

What helps

• Arrange the inspection as early as practicable, before evidence is lost or disturbed.
• Photograph the damage before make-safe work starts.
• Keep removed materials, such as broken tiles or damaged flashings, until the consultant has seen them, where it is safe to do so.
• Keep the make-safe report and invoices.
• Give the consultant any maintenance records and earlier reports.

When a specialist is needed

Some questions need other expertise:

• a structural engineer for structural damage
• a hydrologist where flooding may be involved
• a roof plumber or hydraulic engineer for gutter and downpipe capacity
• an electrician where water has reached electrical work
• an indoor air quality specialist where there is significant mould.

A good report says when another specialist is needed, and why.

For most storm claims, a Basic Causation Report answers the question of cause. Where the history is complex, or the cause is disputed, a Forensic Report goes deeper.