Hoarding Fire Behaviour

In July 2014, Fire and Rescue NSW conducted two ‘build it burn it’ test burns at the CSIRO test research laboratory simulating bedroom fires with differing hoarding levels. The first burn simulated extreme clutter (level 8), and the second moderate clutter (level 5).

The research identified that the type of fuel and its arrangement primarily determines the level of fire risk rather than hoarding level (i.e. fuel load). The risk of ignition does however increase from greater abundance of materials being in close proximity to flames and heat sources. The tests also demonstrated that greater effort is required to extinguish and overhaul fires that involve hoarded material.

Higher fuel loads did not result in hotter fires, however, the intensity of fire does increase when materials have higher combustibility and fire burns at peak intensity for much longer when fuel loads are higher. Surprisingly, hoarded materials may also provide good thermal insulation against combusting materials and hot gases. In the second test, a maximum temperature of 17°C was reached under piled clothing despite gas temperatures above 1000°C within the room.

Working smoke alarms provided early warning of fire offering time for occupants to evacuate if they act immediately. A study into the social science of hoarding is needed to present arguments for greater levels of protection (e.g. interconnected alarms or domestic sprinklers) as attachment behaviour of hoarders may directly influence their response in situations of fire (e.g. unwillingness to evacuate).

The outcomes and findings are available in the Fire Research Report Research Tests: Hoarding Fire Behaviour (PDF)