more roofing questions

[nhdog]

i'm getting ready to close in the roof on my new sugar house and in the ''uvm sugar house design'' they say ''some have put the smoke stack thru the cupola and the stack heat helps draw the steam up''. has anyone done this or have an opinion as to pro or con ?

[minehart gap]

I have done that. I had the top of my 12" steam pipe level with the bottom of the openings on the cupola. Steam pipe had so much draw that I sometimes would have the damper fully closed so the steam would stay long enough to heat the preheater. Not only did the heat draw the steam up the stack, it also created a draft in the cupola that would draw the steam that escaped from the front pan. The method did work when it was windy but not as well.