Foundations in coastal areas must elevate buildings above the Base Flood Elevation (BFE), while withstanding flood forces, high winds, scour and erosion, and floating debris.

Foundations used for inland construction are generally not suitable for coastal construction.

Pile bracing is determined by the foundation engineer. Common bracing methods include knee and diagonal bracing. Bracing is often oriented perpendicular to the shoreline so that it is not struck broadside by waves, debris, and velocity flow (see figure at right). Temporary bracing or jacking to align piles and hold true during construction is the responsibility of the contractor.

Foundation walls include stemwalls, cripple walls, and other solid walls.

• Foundation walls are prohibited by the National Flood Insurance Program (NFIP) in V zones.*
• Use of foundation walls in A zones in coastal areas should be limited to locations where only shallow flooding occurs, and where the potential for erosion and breaking waves is low.
• Where foundation walls are used, flood-resistant design of foundation walls must consider embedment, height, materials and workmanship, lateral support at the top of the wall, flood openings and ventilation openings, and interior grade elevation.

Continuous, properly connected load paths are essential because of the higher vertical and lateral loads on coastal structures.

• Building materials must be durable enough to withstand the coastal environment.
• Masonry reinforcement requirements are more stringent in coastal areas.