The damage caused by fires associated with swimming pools can be particularly difficult to identify. The fire at this loss occurred within a waste bin located in an outdoor recreational area and then spread to the roof of the leisure centre’s plant room. As a result, the centre was extensively damaged including significant amounts of electrical cabling being burnt.
Davis French and Associates (DF&A) were brought in to assess the extent and severity of smoke contamination and to make recommendations for the recovery works. In fires when polyvinyl chloride (PVC) contained in electrical cabling, light fittings and other plastic materials has burnt, the principal cause for concern is the potential for secondary damage. This is because when PVC burns it releases hydrogen chloride as a gas. The gas then combines with moisture in the air to form hydrochloric acid which remains as a vapour and is carried throughout the building by the hot gases and smoke. Hydrochloric acid is one of the most corrosive substances known, therefore when the smoke/gas vapour condenses on cooler surfaces it leaves a highly acidic deposit, particularly damaging to any metal which it contacts.
To complicate matters further, there are usually higher levels of humidity in swimming pool buildings and the chlorine used to keep the pool water clean is another source of chloride which is at far greater levels of concentration than chlorides created by the fire. This made the process of differentiating between the fire-related chlorides and those that were there before the fire very difficult.
The smoke and corrosive gases had reached all areas of the building and could be seen on internal surfaces to air handling units. Identification of the fire residues/corrosion had to be done visually because the testing process used by DF&A cannot discriminate between chlorides generated by the fire and those that were already present due to chlorides from cleaning agents. However, it was possible to visually identify new fire-related corrosion as opposed to older pre-existing corrosion because of the specific colour and it generally forms first on low grade mild steel surfaces, with any longer term corrosion which is unrelated to the incident being much more developed. At this particular site, the only area where it was possible to categorically confirm incident corrosion was a newly installed HVAC system located in the plant room.
DF&A compiled the scope for decontamination works, obtained quotes from several damage restoration contractors and then went on to manage the project for the policyholder for what was a very complex and extensive decontamination phase.