Roof Ceiling Joists

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

Roof ceiling joists.

Ceiling joist spans for southern yellow pine douglas fir and eastern spruce. A broken roof joist is a serious problem that must be taken care of immediately. Ceiling joists provide support for more than one surface in your home. They are used to support a ceiling above or the floor below.

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. Ceiling joist loads ceiling joists are sized based on one of two tables found in the code. 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 joists of the first floor of a two story structure often serve as floor joists for the second floor.

The first surface is unsurprisingly the ceiling the materials of which attach directly to the joists. Joists are traditionally made from timber. Typically the material is plasterboard which can span 450 mm. These span tables list allowable ceiling joist spans for common lumber sizes based on what design load scenario is applied.

The other surfaces are the walls which the joists span the distance between providing a source of support to keep the walls from shifting. The joists are horizontal pieces of lumber that span the distance from one side of the home to the other. For coupled roofs ceiling joists have to be in single lengths or spliced. If this is the case with your structure use the floor joist table to determine maximum joist length load.

They are spaced according to the material they support. Standard size of joists.