[Conde54]

I have started to remodel my bathroom. I want to put in a tile floor. What i have now is plank boards for sub floor. then plywood then cheap 12x12 stick down tiles. Its built up about 3/4 of an inch higher than the hallway. I want to get it down as low as possible so i was curious what anyones advice was. I think the old plank sub floor will be too wavy for tile. I know i need a cement backer board so i was wondering if i should rip it up to the floor Joists and then what? 3/8 OSB and cement board? 1/2 inch plywood and cement board? just cement board? or will the cement board over the planks be fine? Thanks for reading

 

[joecaption]

What size, spacing, and free span are the joist?

3/8 and 1/2 would be worthless. Need 3/4" I would used Advantec T & G subflooring with constrution adhesive on top of the joist and ring shanked nails or better yet ceramic coated decking screws.
Then 3/8 or 1/2" subfloor rated plywood making sure to not have the seams line up with the seams below, and do not nail it to the floor joist.
Then set 1/4 tile board in a bed of thinset and use roofing nails or tile board screws. Then you ready to tape the seams and tile.

 

[oh'mike]

3/4" bc plywood will be fine,if the floor structure is strong enough for tile---then 1/4" Cement backer board or 1/8" Ditra will be what's
needed to ensure that the tile will bond.

Let us know your joist size--spacing--and unsupported length (foundation to beam or other foundation) and someone will run a deflection chart for you----