By John Flanagan
EXPLODE DWG FILE INSIDE REVIT?
Exploding a CAD file inside Revit is not a good idea. The problem is that Revit will change all layers into a Linestyle. That means if you have a large CAD file with many layers, you will have loads of dumb, useless linestyles.
Exploding CAD: A lot of useless Line Styles are created.
Rules to follow when using CAD files in Revit: purge all CAD files, use Link CAD instead of Import CAD. If you really need to explode a CAD file, do it inside of a family or in a dummy project.