Roof Celine Joists

These joists are below the beam and are tied to it by 2x4.

Roof celine joists.

Joists are the parallel horizontal beams that run across an open space joining opposite walls in a building to support both the ceiling below and the floor above. A structural ridge is the standard alternative to ceiling joists. We were told that the joists are not providing structural support and were merely for affixing the flat ceiling. They are nominally 2 inches thick actual width usually 1 1 2 inches and come in a variety of widths from 8 to 12 inches.

Ceiling joist spans for southern yellow pine douglas fir and eastern spruce joist span tables use these tables to determine lengths sizes and spacing of ceiling joists. Joists are traditionally made from timber. In this design the tops of the rafters attach to a load bearing ridge beam that runs along the length of the roof. The joists are horizontal pieces of lumber that span the distance from one side of the home to the other.

These span tables list allowable ceiling joist spans for common lumber sizes based on what design load scenario is applied. The ceiling joist 2x4s are running at right angles to the beam and rafters across the 12ft span of the room. The roof joist is what makes up the ceiling of a home. They are used to support a ceiling above or the floor below.

Before we look at these tables we need to make sure the correct design loads are determined prior to selecting the correct table.