What Is A Floor Joists?
A Floor Joist is a timber beam that is perpendicular to the beam and parallel to the walls for providing a supportive framework to flooring.
This Floor Joist is play a very vital role in the subfloor structure, because they carry the dead load of the furniture, flooring load, vibration of people walking and impact load, etc.
For floor joist used high-quality timber which is help to gives durability, evenness of floor and strength.

This joist must be closely spaced and fixed in nature so that it sufficiently takes all loads like live load, dead load, impact load and sagging of flooring, prevent bending, etc.

Floor Joist load capacities depend upon the following factors,

Grade of the timber or lumber.
Species of Wood.
Length of the joist span.
Load placed on the floor.
Width of Timber Boards
Thickness of Timber Boards.