Our house (we bought it in '97, it was built in '61) came with floor joists at 24" offsets. The hardwood flooring is really squeaky! A few years in, the kitchen floor tiles started popping out. After a few more years of taping the tiles down (really!), we finally stopped dithering about our renovation and redid the kitchen floor. We cross-braced the joists every 18" or so and installed thick and sturdy sub-flooring.

We did that in 2004. The tiled floor has just begun squeaking; I'm worried...

We did similar bracing in our front hall where we installed tile during our extensive renovation in '13. <sigh>

-jk