How to Create Dashed Ceiling Patterns in Revit for Demolished Elements: A Complete Guide

When working with phased construction projects in Revit, interior designers and architects often encounter a frustrating issue: demolished ceiling elements don't display correctly on reflected ceiling plans. While the ceiling perimeter appears dashed as expected, the interior hatch patterns remain solid, creating misleading documentation.

This tutorial is part of our comprehensive Revit for Interior Designers course - get access to complete project files and advanced techniques.
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The Problem: Inconsistent Demolished Ceiling Display in Revit

Understanding the Phasing Issue
When working with a 2x2 acoustical tile ceiling that's been assigned to the "existing" phase and marked for demolition in the "new construction" phase, you'll notice a common problem:

• The ceiling perimeter correctly displays as dashed lines
• The interior hatch patterns (representing the tiles) remain solid
• This creates confusion in construction documentation
• The reflected ceiling plan becomes misleading for contractors

Why Revit Ceilings Don't Display Demolished Patterns Correctly
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The issue occurs because Revit's phasing system only affects the element's boundary graphics, not the material's surface patterns. The acoustical tile material uses a solid hatch pattern that doesn't automatically convert to dashed when the element is demolished.
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At Revit for Interior Designers, we've encountered this problem frequently in our training classes, and the solution requires creating custom materials and hatch patterns.

The Complete Solution: Creating Custom Dashed Ceiling Materials

Step 1: Create a Custom PAT File for Dashed Patterns
Since Revit doesn't include built-in dashed ceiling patterns, you'll need to create a custom hatch pattern using a PAT file. This is a crucial step that many Revit users overlook.

Creating the PAT File:

1. Open Notepad (or any text editor)
2. Type the following code exactly as shown:

 
;%TYPE=MODEL
*24x24DEMO,24x24 Demolished Grid 0,0,0,24,24
90,0,0,24,24
 
;%TYPE=MODEL
*48x48DEMO,48x48 Demolished Grid 0,0,0,48,48
90,0,0,48,48
 
Important Notes:

• The semicolon (;) and percent sign (%) are crucial
• The numbers (24, 48) represent the ceiling tile dimensions
• You can create additional sizes by copying the pattern and changing the numbers
• Each pattern needs a unique name (24x24DEMO, 48x48DEMO)

Step 2: Save and Load Your Custom PAT File

1. Save the file with a .PAT extension (e.g., "ceiling-grid-demolished.pat")

Step 3: Duplicate Your Existing Ceiling Type

1. Select your existing acoustical tile ceiling in the reflected ceiling plan
2. Click "Edit Type" in the Properties panel
3. Duplicate the ceiling type and rename it with a clear identifier  (Example: "2x2 Acoustical Tile - Demo")
4. This creates a separate ceiling type specifically for demolished elements

Step 4: Create a New Dashed Material

1. Use Edit Type under the new ceiling's properties
2. Navigate to the "Structure" section
3. Click on the material (typically "Acoustical Ceiling Tile 24x24")
4. Open the Materials dialog by clicking the small button
5. Right-click and duplicate the existing acoustical ceiling material
6. Rename the new material with a clear identifier  (Example: "Acoustical Ceiling Tile 24x24 - Demo")

 Step 5: Save and Load Your Custom PAT File

1. Go to your custom material's Graphics tab and Surface Pattern settings
2. Click on existing Pattern
3. Click "New Fill Pattern" and select "Custom"
4. Browse to your saved PAT file and select it
5. Choose the appropriate pattern size (24x24 or 48x48)
6. Click OK to load the pattern into your material

Step 6: Apply the Dashed Material to Your Ceiling

1. With your custom material selected, you'll see the dashed pattern in the preview
2. Click OK to apply the material to your ceiling type
3. Apply the new ceiling type to your demolished ceiling elements
4. The ceiling will now display with proper dashed interior patterns

 
Understanding Revit Phasing for Interior Designers
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Phase Settings That Affect Ceiling Display

• Select ceiling to be demolished and adjust Properties
  • Phase Created = Existing
  • Demolished = New Construction
• Under the current View Properties
  • Phase Filter:  Set to "Show All"
  • Phase:  Set to "New Construction" to view the demolished elements 

 
Best Practices for Phased Ceiling Plans

1. Create separate ceiling types for each phase to maintain clarity
2. Use consistent naming conventions for demolished elements
3. Maintain a library of custom PAT files for different ceiling sizes

 
Advanced Tips for Revit Ceiling Customization

Creating Multiple Ceiling Sizes

To accommodate different ceiling grid sizes in your project:

1. Modify the PAT file to include additional patterns
2. Copy the existing code block and change the dimensions
3. Ensure each pattern has a unique name
4. Load all patterns into your project as needed  

Managing Custom Materials Across Projects     

• Save custom materials to your project template
• Export materials to share with team members
• Use Transfer Project Standards to move materials between projects

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Common Troubleshooting Issues

Pattern Not Displaying Correctly 

• Verify the PAT file syntax is exact
• Check that the material is properly assigned to the ceiling type
• Ensure the phase settings are configured correctly
• Confirm the view's phase filter is set to "Show All"

Pattern Scale Issues

• Adjust the pattern scale in the material definition
• Modify the numbers in the PAT file for different tile sizes
• Test the pattern at different zoom levels

Why This Solution Works

This method addresses the core issue by creating materials that inherently display as dashed, rather than relying on Revit's phasing system to modify solid patterns. The custom PAT file generates true dashed hatch patterns that accurately represent demolished ceiling elements.

Conclusion

Creating proper dashed ceiling patterns for demolished elements in Revit requires a combination of custom materials, ceiling types, and hatch patterns. While this process may seem complex initially, it ensures your construction documents accurately communicate design intent.

I would like to acknowledge Doug Bowers and his article on this topic.
 
Want to master more advanced Revit techniques for interior design? These methods are part of comprehensive training programs that cover everything from basic modeling to complex design scenarios.