Bouncy floor - repair from top?
I have a 1930's cottage with a 2nd story addition that was done in 1990. The 2nd floor has always been bouncy. We had some water damage and found what I think is the problem.
The floor joists are 2x6 on 16" centers. The span is about 13 feet in one place and more than 15' on the other side of the room.
I can't afford to pop the roof right now, but I am wondering if we can sister the joists from the 2nd floor down instead of the bottom up? (most of the notes on this board seem to be about repairing/reinforcing from the basement or under the house). The floor decking is particle board that is going to be ripped up anway (due to the water damage). If we do sister the joists, do you think another 2x6 or should we sister with a 2x8?
My simple water leak got expensive all of a sudden!