Hello all I am in the middle of a diy home reno and considering some form of radiant flooring I am currently working on the main floor and have much of the ceiling ripped down (plaster and lathe) before I replace with drywall I am investigating under subfloor tubing that would eventually be tied in to my exsiting hot water rad system as my eventual goal would be to have radiant heat through out the house, but do to budget constraints and the need to work in one area at a time i would like to install the tubing well the ceiling is exposed. Any feedback would be appreciated. Some variables to consider are the house is a 2 storey home, approxiamately 80+ years old rads currently in every room (old rads) Does this plan make sense?? Is under sub-floor radiant heating work well, the exsiting floor upstairs is hardwood in pretty good shape. I will reply to any questions to determine how to proceed. I would like to do as much of the labour myself as possible but am open to the hiring a engineer/architect/consultant does any one know one in the toronto area who specializes in this in the toronto area.