I figured that this may have been reported already, though my search found mostly a bug about climbing through things against windows, not barricades specifically. What I'm finding in my game is that no matter how many barricades I put up on windows, my character (and more importantly, Zombies) can climb right through them.
Outside of tearing down windows and building walls in their places, this issue is game-breaking, considering that fortifying in any conventional way is pretty much useless.
Anyone else experiencing this?