Final answer:
Support for the top and bottom edges of sheathing is provided by blocking or rim joists, which are key components for structural stability and load distribution in buildings.
Step-by-step explanation:
At the top and bottom edges of sheathing, support may be provided by blocking or rim joists. These structural components are crucial in construction for ensuring stability and providing a solid base or edge to work from. The blocking refers to pieces of wood that are installed between joists or studs, which helps to distribute loads and add rigidity to the wall or floor system. The rim joist runs perpendicular to the joists and forms an outer edge of the floor system. It not only adds strength but also serves as an anchoring point for the sheathing, which is the paneling that covers the exterior of a wall or the bottom of a floor. Ensuring that the sheathing has proper support is essential for the structural integrity of a building.