We are sistering a few 2x10 joists that support our 2nd floor bathroom to help support a cast iron clawfoot tub. We have pulled out the kitchen ceiling below (badly stained anyway) and we see that we can set the ends of the sisters up onto the top plate with the old joists on both ends of the room (spans 13').
The problem is that old and new 2x10s are not exactly the same width, right? So is it more important that the bottom edge rests even on the top plate with the old joist, or that that top edges are level against the floor up above.
Also, in a couple of places there is a bit of notching near the top that has to happen to help accommodate the tub drain. Should we get these new joists attached before or after the plumber replaces all the old pipe?
Thanks in advance!