1)Once USE has entered the building, is there a limit to how far it can run inside a wall without being in conduit? Code references appreciated.

2) How near to flowing water (as in a creek) can USE be run without further protection?

3) And speaking of creeks, I'm thinking of sleeving the USE in PVC where it runs over the culvert (because we might not get a full 18" below grade). So what does one use to seal the ends of a PVC sleeve in a situation like this? Is duct seal sufficient? And should I also use duct seal where the USE enters PVC to climb the exterior wall of the building it will be entering?

Thanks for your tolerance of my many questions. Only seven years in the trade, so it'll be "a while" before I've seen it all. [Linked Image]