What part of an I-Joist is referred to as the bottom?

The correct answer identifies the bottom part of an I-Joist as the flange. The flange is the horizontal component at the top and bottom of the I-shaped joist, which provides structural support and stability. In an I-Joist, the flanges are designed to handle the compressive and tensile forces, making them crucial for the overall strength of the joist.

The term "bottom" in this context typically refers to the lower flange, which is essential for supporting the loads applied to the floor or roof system the I-Joist is part of. It is important to recognize how the design of the I-Joist, with its flanges and web, contributes to its ability to carry loads effectively.

While other components like the chord and web are critically important to the structure's integrity, they do not specifically designate the lower part of the joist in the same manner as the flange. The gusset also plays a role in connecting and stabilizing members, but it does not represent the bottom portion of the I-Joist.