Creating Roof Trusses
| Reference Number: KB-00981 Last Updated: 11-26-2014 08:04 AM
The information in this article applies to:
How do I create a roof truss?
Drawing roof trusses in Chief Architect is as simple as drawing and replicating a line - as long as certain conditions are met. Roof trusses in the program are defined by the position of one or more roof planes above and one or more ceilings below, so both must be in place before a truss is drawn.
- The roof and ceiling planes can be automatically generated or manually drawn.
- The ceiling can be composed of the default flat ceiling generated in each room by default, of manually-drawn planes created using the Ceiling Plane tool, or of a combination of the two.
- There must be space between the roof and ceiling in which a truss can generate. Trusses cannot be generated along the line where the roof and ceiling come together, usually on a bearing wall.
To create roof trusses
- Open the plan in which you would like to create roof trusses, or select File> New Plan to open a new plan.
- In this example, a simple 20' x 30' plan with an 8 in 12 pitch gable roof is used.
- Use the Build Roof dialog or the Roof Plane tool to build a roof over the structure.
For additional information on building an automatic Gable roof visit the "Generating Automatic Hip and Gable Roofs" article linked in the Related Articles section.
- Make sure that the desired ceiling structure is created.
- For roof trusses with a horizontal bottom chord, you can use the default flat ceiling created for each room.
- To create scissor trusses, you will need to uncheck Ceiling over this room on the Structure panel of the Room Specification dialog and then draw Ceiling Planes .
- In this example one half of the structure has the default flat ceiling, and the other half has a sloped ceiling with a pitch of 4 in 12.
- Select Build> Framing> Roof Truss from the menu, then click and drag a line at the location where you would like roof trusses.
- Select 3D> Create Perspective View> Perspective Framing Overview to see the results so far.
To replicate trusses across a structure
- Select File> Close to close the framing overview and return to floor plan view.
- Make sure that Display Temporary Dimensions is enabled.
- Click the Select Objects button, then click on the truss to select it.
- If you select a roof plane, ceiling plane, or other object instead of the truss, click the Select Next Object edit button or press the Tab Key on your keyboard until the truss is selected.
- When the truss is selected, a dimension will tell you how far it is from a perpendicular wall. Click on the dimension, type 0" in the text field, and press Enter. The truss will move so that it is positioned over the wall.
- With the truss still selected, click the Multiple Copy edit button.
- By default, the Multiple Copy interval for trusses is 24" (600 mm). To change this interval, click the Multiple Copy Interval edit button and specify the desired Primary Offset value for trusses in the Multiple Copy dialog.
- Click and drag the truss's Move edit handle towards the other end of the structure. As you drag, new trusses will be created at regular intervals. Release the mouse button to complete the command.
- Select 3D> Create Perspective View> Perspective Framing Overview to see the results.