Metal mesh holes? Coating wood?

[Butcher]

Hello! I'm new to this forum!
Im not sure how things work around here so i made this post to get more used! i have two questions that i have a hard time answering.
Do i need to coat the wood of a shelf or a cage bottom so it doesnt soak in urine?
and two, how small should the gap be on a metal mesh so a ww dwarf hamster doesnt escape? (centometers or milimeters please!)

[LunaTheHamster1]

Hi and welcome, yes you can use something like Plastikote to protect wood from urine.

I use 6mm mesh for robos/dwarfs