Which element is essential for a roof to support mechanical and electrical equipment?

The deck is crucial for supporting mechanical and electrical equipment installed on the roof. It provides the structural foundation necessary for these heavy items, ensuring stability and safety. The deck must have sufficient strength and integrity to bear the load of the equipment, as well as withstand the various environmental factors it may be subjected to, such as wind or snow.

While other elements like fascia, underlayment, and flashing play important roles in roofing systems—like aiding in water drainage, providing insulation, or preventing water intrusion—they do not serve the primary function of supporting equipment. The deck is specifically designed and constructed to bear weight, making it the essential element for this purpose.