[Stefan-A]

Got the hinge from a local hardware store. They sell them as "piano-" or "furniture hinges". It was pretty cheap.

The roof on my terrarium is basically a wooden frame with a metal mesh (also from a local hardware store), that fits inside the terrarium walls and is held down just by friction and the weight of the spotlight and the aquarium light fixture. It's heavy enough for garters, but a bigger snake might be able to move it. So when I need to get a big branch or something similar in or out of the terrarium, it's easy to do it from above. If I wanted to secure it, it would be easy to just grab a drill and make holes for pins.