What type of material should be used as solid blocking between joists for conventional light-frame construction?

Solid blocking between joists in conventional light-frame construction is typically made of wood. This is because wood is lightweight, easy to work with, and provides adequate support and stability for the structural framework. It helps distribute loads evenly across the joists, preventing them from twisting and maintaining the overall integrity of the floor system.

Additionally, wood has good mechanical properties, allowing it to absorb and disperse forces effectively, which is crucial for maintaining the structural integrity of the building. Furthermore, using wood blocking allows for easy installation and alignment with existing framing components. Other materials like plastic, steel, or concrete may not offer the same benefits in terms of weight, workability, and compatibility with the common practices in light-frame construction.