On the coast, you need building materials that will stand up well to salt water, heavy rain, and wind. In most cases, hardwoods like teak, ipe, mahogany, and other common boat-building woods perform well in saltwater locations. Cement board siding also works well in coastal environments. Composite and plastic materials can be viable alternatives but are expensive and not available for all applications. Hard-wearing exterior paint will serve you well in protecting materials against the elements. Pay close attention to areas where two pieces join, as this is where problems tend to start.