Top chord live load snow and other temporary loads top chord dead load roofing materials weight of the truss itself other permanent items attached to the roof bottom chord live load storage or living space and bottom chord dead load.
Attic truss bottom chord.
Removal has left them extremely vulnerable to collapse due to spreading especially under snow loads but also under just the load of the roof itself.
Factors that determine the size of the bottom chord include on center spacing dead loads applied to the truss span and if there is any pitch applied to the bottom chord.
Those trusses were engineered with a heavy critical dependency on the bottom chords which are in tension.
The bottom chord therefore carries combined stress of both tension and bending of the truss.
A triangle is the simplest form of a truss and the bottom chord is the base piece.
On the general panel of the roof truss specification dialog.
Room in attic trusses or more commonly attic trusses allow for living spaces within a truss.
Check the box beside force truss rebuild.
Attic trusses are popular over garages or anywhere people want to increase living or storage space without adding another floor to their structure.
The bottom chord is increased and loaded for live loads similar to floor systems in residential spaces.
In this case 11 7 8 will be used.
Check the box beside attic truss.
Change the bottom chord depth to match your floor structure depth for floor 2.
The roof system is basically a hinge now.
The horizontal beam of the triangle of a bottom chord is used in this simple triangle truss construction.
About the bottom chord.