Final answer:
Joist hangers are required where joists cannot rest on a support, such as in deck and balcony construction.
Step-by-step explanation:
Joist hangers are metal brackets that are used to support and connect joists to beams or other structural members. They are required in situations where joists cannot rest directly on a support.
Joist hangers are commonly used in deck construction, where the joists need to be elevated above the ground or other surfaces. The hangers provide a secure connection between the joists and the supporting beams, ensuring the structural integrity of the deck.
Similarly, joist hangers are also required in balcony construction, where the joists need to be connected to the main structure. The hangers help distribute the load evenly and prevent the joists from sagging or being damaged over time.