Roof Rafter And Ceiling Joist Framing Section

The roof framing modification factors shall take into consideration the climatological location.

Roof rafter and ceiling joist framing section.

Roof ceiling framing rafter joists exterior wall nailed to rafter ceiling joists parallel to rafters 2006 irc r802 3 1 in the 2006 edition of the irc the subject of rafter joist connection has been simplified. When incorporated into a floor framing system joists serve to provide stiffness to the subfloor sheathing allowing it to function as a horizontal diaphragm. In a rafter roof all of these components are required to provide. The following is excerpted from the international code council icc s international building code section on ceiling joist and rafter connections.

Additionally be sure to adhere to the specific fastening requirements in the 2018 irc table r802 5 2 for the rafter to rafter tie ceiling joist connections. 2308 10 4 1 ceiling joist and rafter connections. R802 3 1 ceiling joist and rafter connections. There are several variables to consider when determining the proper rafter size.

The general requirement is for all joist to be connected to rafters at the top of the wall. The diagram above depicts the cross section of a typical prescriptive roof consisting of the rafters a ridge board ceiling joists and collar ties. 27 c and for roof framing. R802 1 5 8 exposure to weather.

Ceiling joists and rafters shall be nailed to each other and the assembly shall be nailed to the top wall plate in accordance with tables 2304 9 1. This sizing guide for roof rafters will help determine what you need for your small project. Joists are traditionally made from timber. 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.

The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Section r802 wood roof framing. 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. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

For example in a roof structure where the ridge height is 9 feet above the top of the support walls the maximum height that a rafter tie can be raised is 3 feet 3 9 1 3. The framing details required in section r802 apply to roofs having a minimum slope of three units vertical in 12 units horizontal. A joist is a horizontal structural member used in framing to span an open space often between beams that subsequently transfer loads to vertical members. California residential code matrix adoption table chapter 8 roof ceiling construction.