Assuming the joists are in good condition the solution to both sagging and bounciness problems is to reinforce the floor.
How to reinforce a floor from underneath.
If your subfloor is accessible from underneath the process of reinforcing it is a quick one.
There are a variety of ways to stiffen a floor.
Either way they are put in to lend support to weakening walls and.
Depending on cost and practicality they could mean beefing up the floor joists or adding new support underneath with new or reinforced posts of support beams.
By building a wall under joists you divide the span.
You may need to reinforce your floor joists if you have saggy floors in your house.
If the subfloor isn t strong enough this can cause a constant squeaking in the affected weak section or sagging of the subfloor panels and joists.
Floor joists will help to bring up walls that seem to be falling in.
Floor joists can be found under the house for example in the crawl space.
How to reinforce floors with a crawl space foundation.
Reinforcing the subfloor with blocking adds strength to the surface simply by stiffening the floor joists.
If the wall will have a doorway place a double 2 6 header above the door s rough opening.
The floor above will be stiffest if you place the wall in the middle of the joists.
If you build a wall to support joists be sure to place a stud directly and tightly under each joist.
If the crystal goblets in the china cabinet chime musically when someone walks across the room or if the floor just feels bouncy the.
The method or methods tom chooses depend as much on practicality as on effectiveness.