If I build a smal temporary area in my garage, how can I heat the top of it as my garage door will get in the way if I try to build to the ceiling. My garage was an after market add on and I have 12' from floor to ceiling, I am thinking I can add a "roof to it.
If I'm understanding the situation correctly, you can just build a temporary structure that built up to a height that comes to just below the garage door track. And then just a basic flat roof. Years ago a friend of mine did something like this and actually ended up with a pretty sturdy structure, even though two of the four walls were floating and just rested on the floor (with insulation shoved in the gaps formed by a less than flat floor). If I remember correctly he used two existing exterior walls and then tied to floating 2x4 walls into them to form a large rectangle. He was trying to sell the house so he built it so the garage door could still be opened.
Reflectix can be used to keep heat out. If you're building a temporary structure you'll have a built in air space of sorts and won't have to worry about anything overheating or moisture getting trapped in structural walls.
I can't promise you it will keep your temporary room cool enough in the summer, however.
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Currently keeping a small collection of various Gonyosoma. Both G. janseni and G. oxycephala.