Corrosion Protection for Metal Connectors in Coastal Areas for Structures Located in Special Flood Hazard Areas in Accordance with the National Flood Insurance Program [open pdf - 717KB]
"An important objective of the National Flood Insurance Program (NFIP) is to protect buildings from the effects of hurricanes. The NFIP regulations include requirements concerning the resistance of buildings to flood and wind forces (as described in the following section). For a building in a Coastal High Hazard Area to comply with these requirements, many of its components must be adequately anchored. In wood-frame buildings, the necessary anchoring is usually achieved through the use of metal connectors such as joist hangers, truss plates, and hurricane straps. The need for such connectors is especially great in coastal areas, where storminduced flooding and high winds pose significant threats. However, metal connectors are subject to corrosion when exposed to moisture and salt, both of which are prevalent in coastal areas. This bulletin describes the causes of accelerated corrosion of metal connectors in buildings located near the ocean and some larger saltwater bays. The variation in the corrosive environments within a typical building is also described. This bulletin outlines available corrosion-resistant materials and methods of maintaining proper anchorage for the life of the building. It recommends connector materials for buildings at various distances from the ocean and for different exposure conditions within an individual building. Few local building codes and no national building codes address accelerated corrosion near the coast. This bulletin describes areas where corrosion is known to be a problem and recommends a variety of solutions."
Technical Bulletin 8-93
Federal Emergency Management Agency: http://www.fema.gov/