Final answer:
Header joists, also known as rafters, are horizontal structural members that support the weight of the roof and transfer it to the walls in residential construction.
Step-by-step explanation:
Header joists, also known as rafters, are horizontal structural members that support the weight of the roof and transfer it to the walls. They are parallel to the ground and run from one end of the building to the other. Header joists are typically made of wood and are used in residential construction.