I am trying to figure out what is inside of my exterior plaster wall that the brick is attached to. The house was built in 1946, has no insulation in the walls, and (oddly enough to me), has drywall with plaster on top of the drywall. I was actually expecting wood lathing of some kind. I'm assuming the sheathing is some kind of gypsum or fiberboard sheathing but wasn't sure if that was even around in 1946.
The first shot shows the sheathing through the hole in the plaster. The second shot has the sheathing on the left (with water damage). When you push on it with your finger, it is a little "squishy" and not firm like regular drywall.
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