Australian Institute of Sports Aquatic Training & Testing Centre

Indoor aquatic centres differ in one very significant way from other buildings - they contain a large surface area of heated, chemically treated water. The atmosphere of indoor swimming pools is one of the most aggressive to be found in any building environment. 
 
Higher water temperatures combined with an increase in the number of swimmers has led to higher levels of harsh chemical disinfectants being used. The use of Chlorine-based disinfectants is common practice, which together with other contaminants introduced by swimmers, produce chloramines which are extremely corrosive of ferrous metals. Higher levels of humidity can lead to condensation in cooler parts of the building. Recirculation of pool air can increase humidity, as well as adding to the build up of contaminants in the atmosphere. As the humid air rises it tries to find an escape via the easiest route - usually into the roof space. Without a well installed vapour control layer, this humid air passes through the ceiling and the insulation into the roof space where a build up of condensation and aggressive concentrations of chlorine-containing species may build up, causing ruinous problems such as corrosion of ferrous metals and rotting timbers in load-bearing components, mould formation and loss of thermal resistivity. Unfortunately corrosion in an aquatic centre in Switzerland went unnoticed and tragically in 1985, after only 13 years of use, 12 people were killed when the swimming pool roof collapsed.
  
The avoidance of roof space condensation in high humidity buildings requires careful consideration at the design stage on the correct use of closed cell thermal insulation, vapour control layers and breathable membranes that allow the building to breathe.
 
Since being established in 1984, the AIS in Canberra has undergone two major roof refurbishments due to corrosion. At the second attempt, the foil backed glass fibre insulation was replaced by a sufficient thickness of a continuous closed cell Dow Styrofoam insulation to keep the roof structure above dew point. Installing Proctor Roofshield above the insulation and under the roof sheet allows for the controlled escape of vapour whilst restricting the ingress of moisture back into the building envelope, helping reduce the risk of corrosion attack and the likelihood of a need for a third refurbishment.