On the contrary modern houses often rot because of the water barrier. Condensation gets trapped in the wall and it rots really fast. If you insulate your old house from the inside you wont have this issue. I spent the last 3 years remodelling at 1875 house and we opened all the walls to spray urethane foam. It sealed all the cracks between the wood beams but still leaves the exterior untouched to moisture can leave.
Yeah any house build in the 70’s, 80’s, or early 90’s might had issues with moisture. Water vapor in particular.
Im not sure I’d spend the money (or desire the inconvenience) on a job like that on my old home. I’m not sure I’d make the money back in savings during my time here. But during a gutting, makes sense.
