Hi Jorma, I tested the issue with Tekla Structures version 19.0 SR2. It seems that you can get the surface treatments exported to IFC by selecting first the desired surface treatments (and objects) in Tekla Structures and then selecting "Create selected" button in the IFC export dialog. I noticed that if the "Create all" option is used the surface treatment objects are not for a some reason exported to IFC model. The issue has been forwarded to Tekla Structures development. Thanks, Heikki