Creating a Vaulted Ceiling and Scissor Trusses


Reference Number: KB-00068
Last Modified: January 6, 2020

The information in this article applies to:

Premier

Home Designer Professional



QUESTION

How do I create a vaulted ceiling and scissor trusses? 


Cross Section view of a scissor truss

ANSWER

In Chief Architect, roof trusses are generated in the space between the roof planes above and ceiling planes below. When a vaulted ceiling has a different pitch than the roof planes above, scissor trusses are produced.


To build the roof

  1. Launch Chief Architect and use Open Plan to open the Chief Architect plan in which you would like to create scissor trusses.

    In this example, a simple 20' x 30' rectangular plan is used.


    Floor Plan view of 20' by 30' building 


  2. Using the Select Objects tool, select the walls to make gable ends, then click the Open Object edit button.

    In this example, the left and right walls were selected.


  3. On the Roof panel of the Wall Specification dialog, select the Full Gable Wall option and click OK.

    Roof panel of Wall Specification dialog showing Full Gable Wall selected


  4. Select Build> Roof> Build Roof  and on the Roof panel of the Build Roof dialog that displays:

    • Check Build Roof Planes.

    • Set the desired Pitch (in 12).

      For this example 10 in 12 pitch is used.

    • Check Trusses (No Birdsmouth).

    • Click OK to build the roof.

      Floor Plan view of building with Roof Planes


To build the ceiling

  1. Using the Select Objects  tool, click in the room that will have a vaulted ceiling to select it, then click the Open Object  edit button.


  2. On the Structure panel of the Room Specification dialog, uncheck Flat Ceiling Over This Room, then click OK.


  3. To make it easier to draw ceiling planes, select Tools> Layer Settings> Display Options  and in the Layer Display Options dialog for the active layer set:

    Layer Display Options dialog with Roof Planes layer deselected for Display

    • Scroll down to the Roof Planes layer and remove the check in the Disp column or from the Display checkbox.

    • Click OK to close the dialog and turn off the display of the roof planes in the plan.


  4. Select Build> Roof> Ceiling Plane  from the menu.

    • Click and drag a baseline along the outside of a wall defining the room that will have a vaulted ceiling.

    • For best results, the baseline should be along the outside edge of the framing layer of that wall.

    • When the baseline is complete, click once in the room to set the ceiling planes ridge.  

      First Ceiling Plane being created


  5. Click on the ceiling plane to select it, then use the edit handles that display to stretch it across the room to the inside surfaces of the gable walls.

    • In this example, two ceiling planes will form a ridge in the center of the room, so make sure the ridge edge of this plane does not extend past the middle of the room. 

      Ceiling Plane resized to go from gable wall to gable wall


  6. With the ceiling plane still selected, click the Open Object  edit button and on the General panel of the Ceiling Plane Specification dialog:

    Ceiling Plane Specification dialog showing 109 1/8" Height Outside Wall and 6" Pitch

    • Make sure that the Height Inside Wall  is locked.

    • Specify the desired Pitch for your vaulted ceiling.

      For this example 6 in 12 is used.

    • Now lock the Pitch and set the Height Outside Wall to match the Top of Plate value.

    • Click OK to close the dialog and apply the change. 


  7. Repeat steps 4 through 6 to create a second ceiling plane opposite the first one.

    Second ceiling plane created and resized


  8. Click on the ridge edge of one of the ceiling planes, 

    Ridge edge of first ceiling plane selected


  9. Click the Join Roof Planes  edit button then click the ridge edge of the other ceiling plane. 

    After clicking on the Join Roof Planes button, select the ridge edge of the second ceiling plane


  10. The two ceiling planes will calculate pitch and distance and will join where the two planes would intersect. 

    Floor Plan view showing building and two joined ceiling planes

    If you wish, you can turn the display of roof planes back on in the Layer Display Options dialog.



To create scissor trusses

With both the ceiling and roof planes in place, you can now create roof trusses.

  1. Select Build> Framing> Roof Truss  from the menu.


  2. Click and drag to draw a roof truss perpendicular to the ridge line of the roof and ceiling planes.

    First Truss created


  3. Click on the truss to select it and move it so that the exterior edge of the truss is aligned with the exterior edge of the framing layer of the wall.

    Truss moved to outside edge of gable wall

    Note: By default, trusses will snap to align over an outer wall, or to the corner of a roof plane. This can be prevented to allow for manual control of the truss by checking "No Special Snapping" on the General panel of the truss's specification dialog.

  4. With the truss still selected, click the Multiple Copy edit button, then click the Multiple Copy Interval  button to open the Multiple Copy dialog. Verify that Offset Between Copies When Dragging is selected and that the Primary Offset specified for All Trusses equals the desired O.C. truss spacing, then click OK.
    In Home Designer Pro, use the Transform/Replicate Object edit tool instead.

    In this example, a primary offset of 24" is used.

    Multiple Copy dialog showing 24" as the Primary Offset value for trusses


  5. Click and drag the truss's Move  edit handle to create copies at regular 24" intervals.

    Floor plan view showing the truss copies being created with the Multiple Copy tool


    The trusses over the walls on the ends will be a full size truss. If you wish to have end trusses instead, group select the end trusses and then open the "Roof Truss Specification" dialog. On the General panel, put a check in "End Truss" and "Force Truss Rebuild," then click OK. 


  6. Select 3D> Create Perspective View> Perspective Framing Overview  to see the results.

    3D framing overview displaying roof trusses