spiral staircase support idea, NC 20x30 1.5 story

[ceabrm]

i'm trying to work in a spiral staircase and have spent time thinking also about support for a vaulted ceiling with no visible ties. aside from using the proper ridge beams supporting the roof straight down to the foundation, what do folks think of using the middle pole of the spiral staircase in the very center of the house as added support for the roof?

what i'm thinking is having an additional concrete pier in the center of the crawlspace, 12" round, 4' feet deep. bolt the center pole of the spiral staircase to the pier, run it thru the subfloor straight to the center of the roof. if not running the pole right up to the ridge board, then using some sort of rafter tie or king pin/scissor truss, and bolt the pole directly to the underneath of the tie.

i realize it's going to take some engineering to determine all the particulars, but does this sound like a doable thing? sound too weird? too expensive? too silly?

[Don_P]

Not crazy at all, the concept is fine.