Joists

In general joist refer to the horizontal material that is suspended between two or more supporting walls. Usually floor joists, ceiling joists or roof joists are terms used.

Joists (floor joists) most commonly used is meant as the joists to support the 1st floor in a 2 storey building, and for the ceiling to be fixed to on the ground floor. These joists are usually sized for their structural properties and either built in to the wall for support, or fixed into joist hangers that are in turn fixed to a structural wall.