Help in regards to Apex Destruction.

Hi all, I’m stumped and would like some assistance.
In my class we’re creating a game called “Stompy” about a giant romping around destroying buildings and what not.

We’re aiming for something more along the lines of this destruction demo, currently I am unsure of how to go about it. With the “Impact damage” setting on, the entire wall will crumble in one hit, but if I fiddle with the support settings, the wall wont crumble after it’s been hit once.

Also, while I’m here I’d like to disable the debris collision after they’ve broken off, but I’m unable to figure that out.

I’m certain it’s a simple and easy fix that I stupidly missed, but I’d appreciate any and all help thanks.