Patching sub-floor cement board
 

http://www.kradak.com/Uploads/1-IMG_7383.JPG

My master bathroom used to have a vinyl floor and a fake modesty wall separating the shower/toilet zone from the vanity zone. My wife and I aren't as modest as when the house was built in 1965--heck, we don't even sleep in separate beds!

Anyway, I pulled up the flooring and got rid of the fake wall. I pulled up the 2x3 sole plate, leaving a gaping hole down to the wooden sub-floor.

Do you have any suggestions as to what I should do here?

(a) When tiling over, just make sure the tiles are large enough to span the gap--the tile should be strong enough
(b) Fill it up with leveling compound
(c) Fill it up with a concrete patch
(d) Screw in a 2 1/2" wide piece of durock and tape and mortar the gaps
(e) Pull up the whole floor and re-do it all, or
(f) Torch the place and start fresh with the insurance money

Thanks,

Chris

It depends on what the second sheeting is and how flexable the floor is. You may want to remove and replace it, if it is 1/2" particle board. If it is solid I would fill it with wood and cover the whole floor with a concrete underlayment.

Neal,

The second sheet with the cutout shown is 1 1/2" of a 'particle board', but in this case, the particles are aggregate and the board-like material is cement...

Sounds like a substantial floor for vinyl. I think you could do (B), (C) or (D)but waite twenty minutes, someone will correct me.;)

You need to get down to the plywood. Particle board does not stay for tile. How much ply do you have from joists up?

I think this room has had tile before and what he has is some sort of morter bed.

Oh is that what I'm seeing in the picture?
Looked like more P&S over particle board.

Thanks for the assist, guys. I've found an elegant solution: I sent my wife for a masonry course at the local CC and convinced her to do it: she will add a concrete patch to the holes and finish the whole floor with some leveling compound.

All I have to do then is the framing, and electrical, and lighting, and drywall, and plumbing...