The FAYZ Wall is the wall that surrounds the FAYZ area.
Little Pete created the FAYZ wall when there was a meltdown at the Nuclear Plant . LP got distorted when he heard the noises that were made during the meltdown warning. He created the wall without knowing the concequences. However, his movement stopped the meltdown altogether.
At first, the wall looks simply like a thin layer of membrane.
It didn't look opaque, but whatever light came through, it was milky, indistinct, and no brighter than their surroundings. The wall was slightly reflective, like looking into a frosted-glass window. It made no sound. It did not vibrate. It seemed almost to swallow sound.--description of the wall, Chapter 6 of GONE
It was described that it went up and up, but faded against the ground of the night sky and as a wall.
Little Pete's gameboy had been destroyed near the end of the book. It became distorted and caused the FAYZ wall to vanish for just a few seconds then it reappears.
Throughout FEAR, a kind of black substance is creeping up the FAYZ wall from the ground that eventually spreads wider as the substance reach for the top of the FAYZ. The wall then turn completely black and the sunlight that they originally had was blocked off. Sam Temple created Sammy Suns in order the provide light.
At the end of FEAR, a nuclear bomb was thrown upon the wall. The impact cause the FAYZ wall to turn invisible. Although people from each side could see the other side, they still cannot get through.
Alex Mayle's Intrusion in LIGHT Edit
Somewhere near the front of LIGHT , two adults Alex and another unnamed man was attempting to tape the insides of the FAYZ. As Alex was leaning on a ladder upon the FAYZ as Gaia and Diana got near them. Gaia was hungry so she tried to 'provoke' Little Pete mentally and caused the wall to engulf Alex .