replace bouncy tile?

[Joseph L.]

Hey guys , just closed on a property and need some advice.

The house is all tiled but was built in the 40's and the floor is real "bouncy" in different parts with some tile cracking also.  I believe it is because they laid the tile on the original plank subfloor and didnt install a layer of plywood sub floor.

If this is the case what have you guys done to fix the problem?  there is access to the crawl space but not sure if just sistering the joist or anything underneath will be enough.  Is our best bet just to rip out everything and install plywood subfloor throughout the house and then install new flooring? What are general cost to do this per sqft?

thanks for any help,

Joe