There are three distinct types of weathering: chemical weathering, physical weathering, and biological weathering. Salt weathering falls under the category of physical weathering.
Salt weathering is further categorized as a type of crystallization weathering, much like ice crystallization. Often, salt crystallization and ice crystallization occur simultaneously.
Salt weathering occurs when a saline solution gets into cracks or pores in rock. If the temperature changes enough for the ice to crystallize, it will expand in the crack, and may fracture the rock.
Salt weathering is primarily a concern in marine areas where the presence of the ocean ensures a high level of salt in water vapor. Salt weathering also tends to happen in climates that are hot and dry.
The more porous a material is, the more susceptible it will be to the effects of salt weathering.