Yes, the small amount of panels I installed on the smaller of the two doors have already affected the weight of the door enough that I'll have to either adjust the springs or get heavier ones. I was surprised on how they did. I wonder if the empty doors were so light and the springs might have been adjusted at the very lightest position and if there is a "window" of adjustment that I might be able to adjust within. If not, I guess I'll need new springs. Either way I need to insulate the doors.
I do have an a heavy duty electric heater that I had been using earlier this year to do some work in the shop. At that time I just set up a couple of cardboard walls to try to contain the heat and it seemed to work fairly decent when the temps were in the upper 40s. I might use that to supplement the heat from the main area or try to place a box fan on outside the mezzanine to push some heated air under it. Yes, that is the area where I plan to put my work bench, drilling table, drill press and other power tools.
