Hi!

I'm working on retiling my bathroom, and I need to pour self leveling concrete to level the floor. I realize that the floor only needs to be flat, but I also would like it to be level. I have expansion foam to go around the perimeter of the room, but there are some areas that I need to dam, and I'm not sure the best way to go about it.

The major area of concern is the toilet area. I removed the flange and soil pipe, and need to prevent the SLC from flowing into the basement. I don't want to install the soil pipe and flange until the tile is in place, that way I can be sure the flange rests directly on the finished floor. I am flirting with the idea of taping some aluminum flashing to the hole in the floor from the basement just wider than the pipe, but I don't know if the cement will bond to it. :confused: The way the hole looks now, there are the floor joist, 3/4" plywood, then 1/2" Hardibacker, the holes were cut before I knew I had to remove the flange so they are much larger than needed, and pretty inconsistent with each other. :o

The other areas of concern are the pipes for the heater and the doorway.
For the pipes- I'm thinking of using spray in foam insulation "Great Stuff"
For the door- I'm thinking of using a 2x4
I also am going to chaulk around the perimeter between the hardibacker and walls, so the SLC can't seep to other rooms or basement. There will also be the self adhesive foam weather stripping on the wall covering the chaulk, so I think this will be a non-issue.

Any suggestions are greatly appreciated! :)

Have you considered installing a mud bed instead of SLC?

Why do you want the floor so level? Does it slope that much?

Duct tape...

If you coat the aluminum flashing with oil, nothing is going to stick to it. Otherwise, what you outlined sounds much like I would do it. Why not a level floor?