Manually Framing a Dropped Ceiling
| Reference Number: KB-01050 Last Updated: 10-01-2013 08:39 AM
The information in this article applies to:
How do I create a dropped ceiling?
A dropped ceiling is a secondary ceiling, hung below the main, structural ceiling. They may also be referred to as a drop ceiling, false ceiling, or suspended ceiling.
To create a dropped ceiling
- Open the plan file in which you need to create a dropped ceiling.
- In this example, a simple rectangular structure with two rooms is used.
- Click the Select Objects button, then click in an empty space inside of the room that you want to assign a dropped ceiling to select it.
- If you select an object inside of the room, click the Select Next Object edit button or press the Tab key on your keyboard until the room becomes highlighted.
- With the room selected, click the Open Object edit button.
- On the Structure tab of the Room Specification dialog, click the Ceiling Finish button.
- In the Ceiling Finish Definition dialog:
- Select Layer 1 of the ceiling finish definition, then click the Insert button to add a new layer above the selected layer.
- Specify the desired Thickness of the new layer, which will form the dropped ceiling framing. In this example, 3 1/2" is used.
- Click either the Library or Plan Material dialog and specify the new layer's material as a Framing material. In this example, "Framing Fir Stud 16" OC" is used.
- Specify the Structure Type, which is the type of framing you want to use to frame the dropped ceiling. In this example, "Lumber" is used.
- Repeat these steps if you require additional layers, such as an air gap, above the framing.
- When you are finished, click OK to close the Ceiling Finish Definition dialog and return to the Room Specification dialog.
- Notice that the preview diagram represents the Finished Ceiling (F) height.
- The results can also be seen in a Backclipped Cross Section view.
To manually frame a dropped ceiling
If part or all of the platform above the dropped ceiling is a ceiling platform, a dropped ceiling's framing can be created automatically when Ceiling Framing for the floor is generated using the Build Framing dialog.
If, however, the entire platform above the dropped ceiling is a floor platform, the framing must be drawn manually.
- Select the room with the lowered ceiling and click the Open Object edit button. On the Structure tab of the Room Specification dialog:
- Make a note of the Absolute Ceiling height.
- Click the Ceiling Finish button and make a note of the Thickness of the layer or layers located above the framing layer.
- Click Cancel to close both dialog boxes.
- Subtract the thickness of the ceiling finish layers above the framing layer from the Absolute Ceiling height. The resulting value is the top height of your lowered ceiling framing members.
- In this example, this height is 89 1/4".
- Select Build> Framing> General Framing from the menu, then click and drag to draw a framing member across the room with the lowered ceiling.
- Click on the joist to select it, then click the Open Object edit button. On the General tab of the Framing Specification dialog:
- Specify the desired Thickness and framing Type. In this example, 1 1/2" thick Lumber is used.
- Specify the desired Depth, then click the radio button beside Depth to lock this value. In this example, 3 1/2" is used.
- With the Depth locked, specify the desired Top Height. Use the value you determined in steps #1 and 2, above: 89 1/4" in this example.
- Press the Tab key on your keyboard to update the dialog, then confirm that your changes are all correct.
- On the Line Style tab of the Framing Specification dialog:
- Click the Layer drop-down list and select "Framing, Ceiling" from the list.
- Click OK to close the dialog and apply your changes.
- With the framing member still selected, click the Object Layer Properties edit button. In the Object Layer Properties dialog:
- Click to place a check in the Display column for the "Framing, Ceiling" layer and click OK.
- If you unselect the framing member before turning this layer on, or in version X3, select Tools> Display Settings> Display Options from the menu and turn on the "Framing, Ceiling" layer in the Layer Display Options dialog.
- Move the framing member into position along the inside surface of a wall's Main Layer using whatever method you prefer. For example:
- Using its Move edit handle,
- Using a dimension,
- Using the Transform/Replicate Object edit tool.
- Once the framing member is positioned against a wall, select it and click the Multiple Copy edit button, then click and drag to produce copies at regular intervals.
- You can specify the intervals by first clicking the Multiple Copy Interval edit button.
- You can add ledger boards for the lowered ceiling joists using the same steps:
- Draw a General Framing object;
- Edit its Depth, Height, and other attributes as needed;
- Move it into position against a wall.
Hint: You can also make a copy of an existing joist and rotate it to create a ledger.
- To trim the dropped ceiling joists so that they butt against the ledger instead of extending into it, use the Trim Objects edit tool:
- Zoom in on the ledger so you can see it clearly.
- Click on the ledger to select it;
- Click the Trim Objects edit tool;
- Click and drag to draw a temporary fence inside of the ledger and through the joists that you wish to trim.
- When you release the mouse button, all joists touched by the temporary fence will trim to the edge of the ledger.
- You can now see the lowered ceiling framing in a Backclipped Cross Section if you turn on the display of the "Framing, Ceiling" layer in that view.