[jyl]

Originally Posted by Zeke

First of all, I am going to correct myself. Fir T&G floors are self sustaining and therefore are not normally installed over diagonal sheathing. So it very well may be that the next layer of what I called shiplap is over sanded 3/8ths hardwood flooring. Whatever it is, it's done.

Now to the problem at hand, tile. It is nigh impossible to install anything that will look right and perform well over the tile. Adding another layer of any ply or backer is only going to exacerbate the height problem.

I still recommend taking some flooring out, but rather than to the joists, only to the diagonal subfloor. If I am correct about the next layer of floor, the strip flooring, I bet it is barely attached and only held down by the nailing of the ply layer above it.

That should come out in large sections using long, heavy duty pry bars. At that point a new Trekkor style 3/4 sheet secured very well offers a substrate ready for multiple styles of flooring. If tile, then a backerboard is recommended. 1/4 or 1/2, it doesn't make much difference set in thinset. It's just a base for ceramic or porcelain tile. For wood, engineered, or sheet goods, the 3/4 ply should be enough as long as it's prepared well as in nail holes filled, seams reinforced with strip mesh and filled. IOW, a monolithic surface.

A hack would clean your tile, maybe even grind it some, and lay/glue 1/4" sheets on it to start yet another floor. Given the detailed work you did on the exterior, I doubt you will settle for that nonsense.

BTW, HF sells a toe kick saw that cuts flush at the cabinets. It would be best to remove any ceramic tile near the cabinet bases. That leaves more or less a floating floor that once started at a door opening, will lift up, as I have been saying, in large sections. Much neater and faster than beating the tile.

Thank you, Zeke.

Yeah, not paying anyone to hack my house. I'll do my own hacking, thank you :-)

I'm going to pull all the cabinets and remove the old floor underneath. The new base cabinets are free standing pieces on legs w/ hidden self-levelers, so the floor under the cabinets will be visible.