In order to maintain the display of existing drawings when a project is upgraded, concrete elements from legacy (upgraded) projects (created in versions earlier than Revit 2009) will behave differently than newly created objects.
- Valid concrete elements that are not joined will not automatically join with each other. You can join them with the Join Geometry tool, however. See Joining Geometry.
- Newly created elements will automatically join with upgraded legacy elements.
- Newly created concrete elements will automatically join with one another as expected.