So, I was getting overwhelmed by zombies and needed to gain some height. I proceeded to start stacking cades by looking down and crouching then cade really fast. Unfortunately the first cade I placed down started clipping into the ground and freaking out. I'm not sure if its a bug or I am just simply doing it wrong. Any help would be appreciated. 

So, I was getting overwhelmed by zombies and needed to gain some height. I proceeded to start stacking cades by looking down and crouching then cade really fast. Unfortunately the first cade I placed down started clipping into the ground and freaking out. I'm not sure if its a bug or I am just simply doing it wrong. Any help would be appreciated. 

Yes, This happens you will need to place a cade down first and get ontop of it and then continue to stack, i don't think there is any way to fix this glitch, but im pretty sure you can stack without a cade underneath you on some other surfaces!, Hope this helped you.

Jump, crouch, place cades.

Yea, that's the lazy mans stack, to properly stack is like shame said, jump+crouch look down and place a Cade, then continue to spam the shit out of it.