What is the minimum height required for a nonabsorbent wall surface above a bathtub?

The minimum height required for a nonabsorbent wall surface above a bathtub is established primarily for hygiene and safety reasons. A height of 6 feet ensures that the area is adequately protected from water splashes and vapor, which can lead to mold growth or deterioration of wall materials over time. This height is also reasonable for preventing water damage in the areas that are most likely to experience contact with water during routine bathing activities, such as when a person exits the tub or when water is splashed around.

In many building codes, nonabsorbent surfaces are required in wet areas like bathrooms to maintain sanitary conditions. By specifying a minimum height of 6 feet, it ensures that a large portion of the wall above the bathtub remains resistant to moisture, facilitating easier cleaning and maintenance.