How thick can floor leveling compound be?

We have a farmhouse that was built in 1882. One of the (tree) rough cut beams in the basement has pushed up into the bathroom. It doesn't seem to be causing damage, it just makes the floor unlevel. The previous homeowners had carpeted the floor, and we can't stand carpet in a bathroom.

We have decided on marble/stone tile, and would like to know how thick we can apply leveling compound? ARDEX site says that it can be applied up to 5" with the addition of proper aggregate. What would the aggregate be? How noticeable would a 2" (at least) application of leveling compound and then the addition of backer board be? I realize it is going to raise the floor quite a bit, especially after the tiles go in, so, what would be a good room divider, in the threashold?

Thank you very much for your help. We are *very* new to home improvements, so detailed explanations are appreciated.

Stephanie

 

I recently read a forum post where the poster removed the subfloor and reduced the bowed timber beneath by chiseling it to the appropriate height. That is an option. If you choose to use Ardex, then you need to know what aggregates the manufacturer of Ardex recommends. 2" sounds quite extreme as far as the thickness of leveling compound. The largest transitional piece of which I am aware are those for hardwood flooring and they are 3/4" thick. Should you choose to use a floor leveler of 2", then you add 1/4" backerboard and 1/4" tile. You are looking at 2 1/2". That's quite a step up. This will involve an adjustment of baseboards, door frames and doors, as well has coming up with a custom transitional piece and living with the step up to the bathroom. Let us know what you decide to do.

 

Excellent idea about the chiseling. I think we will try that. That project was put on the "back burner" for a few weeks, we are replacing our barn roof for right now. Will let you know how it all turns out. Thank you for the reply.