I have a new workshop and I'm running 6/3 out to it. My run will need to go from my existing panel through the attic, down an external column (with normal housing siding) and then into an underground conduit.
I understand for the conduit portion of the run I should use THHN but do I need to change to romex for the attic part? Seems I should be able to just continue with the THHN, correct? I know THHN is unprotected but its not like its going through normal walls and it will basically be "inaccessible".