I purchased a house built in 1960 and like other people have mentioned the terrible bounce, I got the same exact situation.
I'm thinking of installing blocking to strengthen the floor.
The 7 joists are spaced 14½
However, since they're all buckled at the lower part of the joist, ranging from 14⅛ – 14⅞
I wanted to know if it's safe to wedge between 14½ blocks forcing them to move back that extra space.
(see below picture)
I also so wanted to know if this load sharing would cause to much weight on other parts of floor beams.
Best Answer
I would sister several of the joists, then add solid blocking in each span. The blocking might not be critical, but the ceiling is now open so why not? Solid blocking does not need strapping across the bottom.
Look closely where the joists meet the load-bearing wall at each end. A 2x6 ledger might give extra assurance. Look at the rest of the floor structure for any splits, sags, movement, etc.