A while ago my dad decided to refloor his bathroom. He pulled up all the old tiles and left the subfloor. The subfloor which seems to be made out of particle board and 1xX boards was rather stinky (not toilet stinky but cutback? adhesive subfloor stinky) so I get the bright idea to help him by covering it with some cementious underlayment (used Armstrong S-184 i think) because he'd been inhaling that floor for over two weeks while deciding what tiles to get or whatever reason. Anyway, I did a lousy job and now the floor is bumpy. I been knocking off high spots with a chisel, but I despair of getting it flat. Any ideas on how to proceed? (Bumps are noticable when tiled over).
I thought about using self leveling underlayment. Home Depot now has a new Henry product, but it looks like my subfloor doesn't meet the spec (particle board seemed to swell up as high spots) and Lowes had some Lactirete product, but apparently they don't carry the primer for it.
Another idea some random guy told me was to put down luan over the floor, not sure this is a good idea to have in a bathroom ... won't the layer act as a moisture trap, and not sure it'll do much for the bumps.
The last idea is to rip up the subfloor and replace the boards with approved subflooring (and forget about the underlayment) which I guess will be expensive. I have no problems with taking the toilets out (it'll be the 4th time <sigh>), but I worry about matching the subfloor height with the bath tub (which I will not take out) level, plus I really don't want to replace the subfloor.
The bathroom area is about 75 tiles so I guess <75 sq. ft worth of flooring. Any ideas or suggestions?