Thanks guys. This kind of feed back is just what I was looking for!
bmike I did look at the warmboard. That looks really slick!
Tim, I'm thinking of using Arma Foil.
http://www.energyefficientsolutions.com/rbproducts.aspAs I take in all these ideas, I am curious to know if I were to:
~ Nail down the T&G pine ceiling boards
~ Cover pine with a layer of the Arma Foil
~ Nail down the beveled plywood sub-floor
~ Lay 8in strips of foil over the grooves
~ Push plex tubing into grooves, trapping foil
~ Install hardwood flooring
Am I getting closer?
I also wanted to describe the building layout. The barn is a 28ft x 40ft three bay timer-frame. The first floor will be fully open except for a couple of small rooms (bath, storage) with a couple of heating zones, and will be used minimally. I can access the first floor from the basement. The center bay has a cathedral ceiling with a possible wood burning stove. The west end bay will have an open loft with a heated floor with it’s own heating zone. The east end bay loft (14ft x 28ft) will be used the most as a farm office/study. It will have a partition wall separating it from the center bay. The height of the first floor ceiling below the loft is just under 8ft. It is this bay that I am trying to design the heated floor system for.
Rooster