Proplem when I Import file from Revit.

Hello everybody. I’m a newbie. I have some trouble with my file Revit. When I import my file from revit to UE4, my roof is broken down into parts. And It’s inside Details of Actor. Can I expode or destroy it and merge my roof to 1 stactic mesh. (I draw my Roof with Curtain Panel Pattern in Revit).
Ps: Sorry about my English. It’s super weak :D. And I don’t know where to find my problems in Doc Unreal . Thank you everyone :smiley: