6.1 Salt Spray from Breaking Waves and Onshore Winds

Salt spray from breaking waves and onshore winds significantly accelerates the rate of corrosion of metal connectors and fasteners. Ocean salts, which are primarily sodium chloride but include other chlorides and compounds, accumulate on metal surfaces and accelerate the electrochemical reactions that cause rusting and other forms of corrosion. The combination of salt accumulation on the surface and the high humidity common in many coastal areas further accelerates the corrosion rate of untreated steel and other metals commonly used in connectors, fasteners, and other building materials. The longer a surface remains damp during the normal daily fluctuations in humidity, the higher the corrosion rate. Onshore winds carry both salt and moisture inland from the ocean. Therefore, corrosion rates are higher along shorelines with predominantly onshore winds than along shorelines with predominantly offshore winds.