Loading Class Manual for intelliVIEW – Chapter 12
Standard Attic Loads
The truss shown above is known as an Attic Truss or a Room-In Attic. This type of truss carries a
combination of Roof and Floor loading. It is also considered to be an indeterminate structure as
it has a non-triangulated web area, which interrupts the normal flow of forces thru the truss.
Proper analysis of an attic requires multiple load cases with multiple duration factors.
Attic Trusses are used for various conditions and are defined as either Habitable or
Uninhabitable. The classification as habitable or uninhabitable determines the amount of load
that must be applied to the open room area. Excerpts from, "ANSI/TPI 1-2002 Appendix B (Non-
mandatory) RECOMMENDED MINIMUM DESIGN LOADS" (shown below) explain the
differences.
