Thank you for reading my post.

I want to know if I should pull-up the entire sub-floor of my guest
bathroom.


My house is a 1982 tri-level (kit?). 50 foot x 25 foot. Most floor &
ceiling joist are 24" OC. The joist run the width of the house.

The guest bathroom (full bath) had a tile floor on a mortar bed, that I
removed.

The sub-floor that's under this tile floor is 1/2" plywood with some
sag on the outer ends and very springy between joists.
Is this normal after removing a mud-tile?

I ran a "stud-finder" along the floor, and
found that the joists are NOT 24" OC and more like 16"OC it a
hit-and-miss pattern... (guest bath is in center of the 3rd floor/
Master bath is on opposite wall of guest bath.) Is this ALSO normal?


~BUT~ my question IS ....
Should I set my circular-saw at just under 1/2 inch, and THEN replace
the entire floor.... or should I just add exterior-grade plywood over
the exisisting sub-floor?

For more information... the "basement" (1st floor) Den, 1/2 bath and
office are 8 foot ceiling, but the basement hallway is 7 foot.
(Bunch of duct-work, plumbing. ect.)


Thanks,
Dave