Ok found it, I installed the thomthom's CleanUp toolset and using the "merge faces" did the trick (5119 faces merged). Saved me a lot of work thanks for the suggestion!

Regards,
Boein

Hi all,

After importing a dxf file (coming from an exported floorplan drawing) in sketchup2015, my model had a lot of X's. It looks like every endpoint of a surface/shape was joined by a line during the import. So I had to remove a lot, and a mean really a lot of those lines. Removing them was sometimes dangerous, deleting the wrong line could delete a part of a surface. So I used the smooth edges tool, clicking on the line and using the smooth edges, removed the line and the surface divided by the 'cross' became again a plain surface. But I didn't know I was not actually deleting the line, just hiding it. Using the show hidden geometry option makes them reappear, and I guess those lines have an impact on processing although they are useless. If using the "show hidden geometry" can show these lines again, I guess it must be possible to create a ruby script to only delete those lines? Anyone knows how?

Regards,
Boein