Roof Ceiling Joists

A broken roof joist is a serious problem that must be taken care of immediately.

Roof ceiling joists. Joist span tables use these tables to determine lengths sizes and spacing of ceiling joists. Joists are traditionally made from timber. The roof joist is what makes up the ceiling of a home. The first surface is unsurprisingly the ceiling the materials of which attach directly to the joists.

They are spaced according to the material they support. 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. They are used to support a ceiling above or the floor below. These span tables list allowable ceiling joist spans for common lumber sizes based on what design load scenario is applied.

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 joists are horizontal pieces of lumber that span the distance from one side of the home to the other. Typically the material is plasterboard which can span 450 mm.

Standard size of joists. Before we look at these tables we need to make sure the correct design loads are determined prior to selecting the correct table. For coupled roofs ceiling joists have to be in single lengths or spliced. Ceiling joist loads ceiling joists are sized based on one of two tables found in the code.

If this is the case with your structure use the floor joist table to determine maximum joist length load. Ceiling joist spans for southern yellow pine douglas fir and eastern spruce.