DougK - 7/10/2018 23:00 The DIY show contractor Mike Holmes has had several shows about this very common issue. He hears lots of complaints about cold floors and drafts in rooms above garages. His cure is almost always to take down the garage ceiling and spray foam the floor above. Sometimes they have to update the HVAC system because it wasn't designed properly. Especially if the rooms above are bedrooms, I think you need to bite the bullet and pull down the ceiling and get a foam contractor in there to insulate it right. Here is a short clip of an episode he did on this issue. https://www.youtube.com/watch?v=cMQYEjJyHVc