My house was built in 1951 in Madison, WI. When we originally bought the house we thought the walls were lath and plaster. The walls are bumpy, cool to the touch, and very thick.
When we did our basement remodeling we discovered that there was no lath and that they appeared to just be giant, thick, dense boards. Not quite a full inch thick, but definitely thicker than modern drywall and not smooth and papery on both sides. It's mounted on 16" on center studs in the walls.
One exterior wall has a rather giant crack that needs to be repaired, and I'm planning on widening a closet door opening in a couple weeks.
So 3 questions:
1. What is this 1950s era plastery-board stuff?
2. Do I patch it like it was plaster? We installed curtain hangers and it took out huge chunks of "plaster" and nails tend to do in with more difficulty than in drywall.
3. Once I've re-framed a new door opening, clearly drywall will be much thinner than what currently exists, what material(s) should I use for having consistency in transition along the wall?
Thanks in advance for any advice!