While the Truss tool does not create log trusses, you can download a Catalog of Components that include a selection of log trusses ready to be placed in your plans.
This article walks you through preparing the structure, placing trusses, purlins, and adding a roof over the top of log trusses.
Roof trusses are generated in the space between the roof planes and the ceiling planes below. When a vaulted ceiling is created scissor trusses are used.
Certain conditions must be met before an attic truss can be built. These include: the structure should be sufficiently wide to allow for a loft and attic spaces, the loft area must be on a living floor and have Attic rooms on both sides separated by Knee Walls, a flat ceiling in the loft area and a floor below, steep enough roof pitch to provide appropriate ceiling height for the loft area. In addition, the roof should bear on the walls of the floor below the loft area and form continuous planes from ridge to baselines. Once all of these conditions are met, a roof truss is ready to be designated as an attic truss.
To create an energy heel, in the Build Roof dialog check Trusses (no Birdsmouth), uncheck Automatic Birdsmouth Cut, specify the desired energy heel height as a positive Raise Off Plate value, automatically generate or manually draw the roof planes, then draw and position the first truss. Open this truss’s specification dialog, check Energy Heel and Force Truss Rebuild, then click OK and use the Multiple Copy edit tool to replicate the truss as needed.
Create exposed trusses by making a ceiling to define where you want the trusses' bottom chords, drawing the trusses, and then removing the ceiling.
Roof trusses are defined by the position of one or more roof planes above and one or more ceilings planes below, so both must be in place before a truss is drawn.