Where should squash blocks be located in a wood I-joist floor system?

In a wood I-joist floor system, squash blocks should be installed at the bearing ends and at load-bearing walls above to provide additional support to the joists. The function of squash blocks is to transfer the load from the I-joists to the perpendicular structural elements, ensuring that the weight is evenly distributed and minimizing the risk of structural failure. By placing squash blocks at the bearing ends, they effectively reinforce the connections where the joists rest on the supporting walls or beams, which is critical for maintaining the integrity of the floor system.

This choice emphasizes the importance of proper load distribution at key structural points in the floor assembly, ensuring that the loads are effectively managed and that the building meets safety and performance standards. The other options may include scenarios that are not standard practices for the placement of squash blocks, such as focusing on splices or plumbing, which do not have the same critical need for additional structural support that bearing ends and load-bearing walls do.