Framing in the addition has a few interesting puzzles to figure out. These puzzles come in two flavors. The first is the problem of marrying new construction to old construction. The second is the problems created by unique space design. I don’t really know much about the history of wood framing. This house has doesn’t use the normal top and bottom plate construction. Instead studs are overlapped between the first and second floor and ceiling joists sit on a rim board that is notched into the stud framing. The interior partition walls are very simply framed with additional wood stuck in to add lathe for the plaster. Additionally, the framing in the addition doesn’t exactly mate to the framing in the main house. As a result, there’s a slope created by the threshold between the two house sections. This is probably due to a combination of settling and poor initial construction. The obvious presentation of these kinds of things is that the hall and bathroom in the 2nd floor have crocked floors. But the less obvious an stranger problems come in uneven joists.
This leads me to the first puzzle. Where the addition meets the main house on the 1st floor, the ceiling joists are uneven by as much as 1.5″. Mostly that’s because of these framing problems, but in addition to that, the lumber in the ceiling is differently sized from board to board. That’s a big gap. Usually you would just nail your top place into the perpendicular joists everywhere they cross. But this isn’t exactly possible if there’s an extra gap between the two. When I took down the original bathroom wall (which was obviously part of a remodel), the carpenter’s solution was to just apply this standard. The result was a bowed top plate and a fractured stud. Not the end of the world, but not exactly the best for structural soundness. My solution was to add additional wood, effectively creating a small run a triple top plate. I have no idea if this is the correct way to deal with the problem or not.
Where two walls meet perpendicularly, you need to have a stud so the end of one wall can be nailed into a vertical board in the other. Depending on how the drywall is going to be run around this corner, you might add up to three studs sandwiched together in order to have this nailing surface and provide surface for the drywaller to attach to. An alternative is to create what’s called a “california corner”. This method uses one stud for nailing purposes and a second stud twisted 90 degrees to make for the overlap. When remodeling, you often have to add new studs to existing walls in order to create this nailing surface. For our project this meant adding lots of wood to the exterior walls. Our house is packed with blown in insulation, so any time we open exterior walls, it’s a big mess. When the new stud fell close to an existing stud, I was often able to nail the two directly together. This solution is easiest and lets me get around the fact that there isn’t a top plate to nail into. I did have to notch all of my boards so they could slide up into the walls, past this rim board. Where they didn’t fall near existing boards, I had to come up with some creative solutions. For example, in one example, I added multiple 6″ horizontal boards to brace the new stud. My guess is that when dealing with old construction, there’s rarely a clear and concise way to go about it. I might be doing it wrong, but it’ll be more an issue of differing opinions on the best way to go about it.