I suppose it depends on if your just going to use it for royals or if in the future you plan on keeping something bigger or stronger in it in the future. Thinking about our viv and monty, he never applies force 0to the sides of the viv. Occasionally uses one side to climb up to the wire on his light but nothing that would put strain and mean a thicker wood is needed.
1.0.0 Royal Python - Monty 1.0.0 Yemen Chameleon - George 0.2.0 Dwarf Rabbit - Poppy & Lola 1.0.0 Budgie - Charlie 1.0.0 Siamese fighter - Lil Blue 0.0.2 Newts - Chris & Louie
Cheers. That's what I thought - I'll definitelly use 12mm as it will be easier to build, will better keep the warm and it doesn't cost a lot more. Thanks for help.