What is the minimum thickness required for unreinforced hollow unit masonry parapet walls?

The minimum thickness required for unreinforced hollow unit masonry parapet walls is 8 inches. This is established to ensure structural integrity and stability, especially given that parapet walls must withstand various forces, including wind loads and potentially the weight of materials or other structural elements. A thickness of 8 inches provides a sufficient dimension to maintain strength while allowing for the modular use of standard masonry units.

Using thinner walls, such as 6 inches, may compromise the wall's performance against lateral loads and its overall durability under varying environmental conditions. Thicker walls, such as 10 or 12 inches, may be stronger but could be unnecessarily heavy and costly depending on the design requirements. Thus, the 8-inch standard strikes a balance between adequate structural performance and material efficiency for unreinforced masonry in parapet applications.