Prior to buying a bunk bed like twin over twin twin over full, check for its sturdiness. This can be done by placing your hand on top bed and shaking the whole unit to check if there is any movement. Also make sure you buy child friendly bunks.

Dont buy bunks with no railings on the top. And make sure they have good solid stairs.

Twin over full also don’t get bunks with corner posts that stick up above the railing, kids can catch things on them and fall, or hang off them, which is not good for your childs safety.