How should freezer and cold-storage facilities be constructed regarding roofing?

The correct choice emphasizes that freezer and cold-storage facilities should be constructed within another building envelope enclosure. This approach is crucial for maintaining the integrity of the temperature-controlled environment necessary for these types of facilities.

By enclosing the cold storage unit within an additional building envelope, you enhance the thermal performance and energy efficiency of the structure. This method helps to prevent heat intrusion from the outside, which is essential for the proper operation of refrigeration systems. It also minimizes the risk of condensation forming on the exterior surfaces, which can lead to moisture problems and compromise the effectiveness of the cold-storage environment.

Other choices either undermine the effectiveness of a cold-storage facility or do not meet the necessary standards. A single-layer roofing system lacks the insulation required to protect against temperature variations, while having no insulation would lead to significant energy loss and inefficient operation. Utilizing lightweight materials may not provide the necessary structural integrity, required insulation value, or durability for the specific demands of freezer and cold-storage applications.