Issue description
You have trimmed a wall to a roof plane. However, the wall is not cropped to the bottom of the roof, instead, it penetrates through the roof structure and its building materials appear on the top side of the roof.
Solution
Check the Building Material Intersection Priorities. One of the materials in your wall composite, could have a higher intersection priority than the building materials in the roof's structure.
- Navigate to Options > Element Attributes > Building Materials.
- Verify the intersection priorities of all building materials assigned to the layers of the individual components (e.g., walls and roofs).
Key rule:
The intersection priorities of the building materials assigned to the wall must be lower than those assigned to the roof. Otherwise, the wall materials will take precedence and penetrate through the lower-priority roof materials.
Tip: In the Building Materials dialog, click on the black arrow to automatically highlight and display at the top, all building materials currently being used by the selected elements (Ensure the relevant elements are selected before opening the Building Materials window).