This summer I plan on building an outdoor enclosure for my Russian tortoise and had a question. What kind of wood should I use to build the frame of it? I know some kinds are toxic, would redwood be okay?
Redwood is fine, but sort of expensive.
Treated wood is now fine, it used to have arsenic, but no longer does. A lot of people use it.
Also exterior plywood, cut into, say, 16" lengths (you get 3 pieces out of one 4'x8' sheet).
Cement blocks. If you use 2 levels, be sure to stagger them.
I usually use regular pine plywood and 2x4s for my stuff. I paint it if I want it to last for a while. I also use a lot of slumpstone block and build frames with welded wire for covers. Like this: