© Copyright 2009 Humidity Control Systems Ltd        Tel: 0044 (1) 522 753722 Dehumidifiers to prevent corrosion of bridges Corrosion of mild steel components and high tensile support wires can soon compromise structural integrity resulting in safety issues, costly traffic restrictions and ultimately bridge closure. According to a 1997 report, of the 581,000 bridges in USA, about 17% were rated as structurally deficient. The cost to rectify these deficiencies was estimated at $78 to $112 billion. While corrosion of the reinforcing steel was not the sole cause, it was a significant contributor and has therefore become a major concern. Steel protection using traditional paint coatings such as EVA and Polyamides is very costly and labour intensive and often fails to meet expectations. Corrosion of internal steel structures and associated support components can normally be eliminated by maintaining the air at 40 to 50%RH.