Ohhh, yeah it is possible that it is tiling connected to one of the walls. You can check out this post I made earlier today where I pointed out a tutorial video that goes over tiling.

http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=617241#Post617241

I'm thinking you may have to undo it from the existing walls and re-do it, or something to that effect. Haven't tried it myself though.

DOS2 Mods: Happily Emmie After and The Noisy Crypt

Steam Workshop
Nexus Mods