Introduction to Water Damage in Commercial Buildings

The most frequent causes of water damage in Australian commercial buildings are:

Plumbing failures including burst cold water supply pipes (particularly in older copper and galvanised steel systems), failed hot water system pressure relief valves, and failed flexi hoses connecting fixtures (a disproportionately common cause of significant water losses in both commercial and residential buildings). In multi-tenancy commercial buildings, a plumbing failure on an upper level can affect multiple tenancies below through penetrations in floor slabs.

Roof and building envelope failures from storm events, failed waterproofing membranes on flat or low-pitch roofs, blocked drainage systems causing ponding water to back up under membrane lap joints, and failed flashings at penetrations. Commercial flat roofs in Australian coastal cities are particularly vulnerable to membrane deterioration from UV exposure and thermal cycling.

HVAC and mechanical plant system failures. Commercial HVAC systems contain significant volumes of chilled and condenser water, as well as condensate drainage systems. Failures in chilled water coils, condensate drain pans, cooling tower distribution systems, and mechanical plant room drainage produce water losses that can be distributed throughout a building via the mechanical infrastructure.

Fire suppression system activations (accidental or deliberate) produce significant water volumes in a short period. Fire system water is contaminated with residual chemical inhibitors and pipe corrosion products and should be treated as Category 2 at minimum.

Reference: IICRC S500 | Building Code of Australia | AIRAH (Australian Institute of Refrigeration, Air Conditioning and Heating) technical guidance