Which of the following is NOT a common use for cement board?

Cement board is commonly used in various construction contexts due to its durability and moisture resistance. It is particularly favored for applications where high moisture exposure is expected, such as in shower installations or kitchen backsplashes. Common uses include finishing walls and serving as underlayment for flooring, especially in areas that require extra protection against moisture.

Concrete board is also often used in certain countertop applications, where its heat resistance and stability under weight can be advantageous. However, cement board is not typically employed as an insulating material for exterior walls. Its primary functional properties do not include thermal insulation, and therefore it does not serve the purpose of energy efficiency or climate control in building structures.

By understanding these typical applications, it becomes clear why the use of cement board as a form of insulation is not appropriate. Insulative materials serve a different function that cement board does not fulfill.