>>509547560>>509547544>>509547527 (OP)Weldor here
1.2 mm is less than 1/16, it's about 1/32.
It's so fucking thin that most weldors can't even weld it. It's sheet metal like you'd find on a trash home Depot grill.
The house is t structurally made of this, it's certainly a normal house that's been plated with this thing foil just for appearances
The underlying structure is probably significantly damaged from the welding process, and the trapped moisture will cause mold and rot at a speed up level