Last year I moved into a house that was built in 1920...2 story colonial. Plaster walls. Hardwood floors. 9 ft ceilings. It's a beautiful house.
I literally have a few tons of books. Most of them are currently shelved in floor-to-ceiling bookcases in one of the upstairs bedrooms. The bookcases are along 3 of the walls. The 4th wall spans the downstairs ceiling, and I didn't want to run the risk of cracking the ceiling plaster downstairs, so that wall doesn't have bookcases.
I've recently noticed thin but long cracks in the plaster running perpendicular to the ceiling on the walls that have the bookcases. Most of the cracks are a few inches from the ceiling. One of the walls backs onto the stairway that goes to the attic. There's also a new crack in the plaster on the stairway wall...this one is lower down, and running perpendicular to the floor.
I think it's safe to assume that the cracks are from the weight of the books. Luckily, there aren't any cracks showing on the downstairs ceiling.
What I was wondering was would it be better to use wall-mounted shelves instead? They would be anchored on the studs that run under the plaster. Would the studs bear the weight better than the floor? That would take the weight off the floors, but would it still cause cracks in the wall?