Need help better isolating my fences

[Spaghettioz]

https://steamcommunity.com/sharedfiles/filedetails/?id=2887865716

As you can see, my fences are encased all around by steel, and I get to them through an iron door. They are at least 4 blocks away to my right and left, and the wire will hit the Zs at the ankles.

Now during day 77 raid, i stayed farther back from the approach just because the absolute volume of spit makes it hard to see anything, and the blasts suck.

No cops blew up at the combat area, or soldiers. They either blew up in my Z pit or in the approach to me.

How the heck is the spit blasts killing my fences? Should I used a vault door perhaps?

I recall it probably being spit because while a couple of Skinny Petes were getting shocked in front of me, some cops were on the way up, and suddenly the fences were gone. Pretty sure the Zs had taken a hit in the back. Do concrete and steel and iron not block blasts anymore?

[Spaghettioz]

https://steamcommunity.com/sharedfiles/filedetails/?id=2887868660

[Spaghettioz]

https://steamcommunity.com/sharedfiles/filedetails/?id=2887868822

[BGratz]

have a look at my base(es)
https://steamcommunity.com/app/251570/discussions/10/3362524231624084858/
And you will see that the Birds are killed by rooftop Turrets (so they rarely spit)
And inside... that moment a Zombie (cop) can see me and start to spit he allready is electrocuted and affected by 2 blades

With other words, nothing spits because
1: It cant see me
2: If it can see me it cant anymore spit


Current testbase (For lategame, the demolisher are a problem i try to solve reliable)
https://steamcommunity.com/sharedfiles/filedetails/?id=2882085864
https://steamcommunity.com/sharedfiles/filedetails/?id=2886368541

[Spaghettioz]

Dude thats brutal xD