Bathroom Floor

[Dennis The B]

We're in the process of replacing the floor in a basement bathroom. The old floor was vinyl tile, and it came up fairly easily. Here are the inherited issues:

• The basement floor drops at least 1.5" from the wall to the bathroom door.
• The commode sat on top of a piece of plywood .5" thick, so it would sit level.
• The existing shower stall is made of concrete block and tiled on the inside.
• The existing sink drain goes into the floor (standard).
• The available floor space is 51 sq ft.

I'm going to use a floating vinyl floor, which will end up as "one piece".

The lady working in the tile floor section at Home Depot suggested pouring a "leveler". However with the amount of drop it would take a huge amount of the "leveler" to level the floor, and I would need to install a fairly high threshhold at the bathroom entry.

My initial idea was to use either .25" or .50" of backer board over the existing concrete floor, using thin set to anchor. However, the folks at HD say the thin set will not bond to the concrete. They also advised that the backer board should not be laid on top of concrete. If I did use backer board, it would need to be anchored to the existing concrete.

With such a small space, and little foot traffic, it would seem that a few sheets of backer board laid snugly to the existing walls, would be enough to anchor the floor, and not have any movement.

Have any of you folks run into this type of problem? If so, what was your solution?

 

[delta-419]

The leveler is a good idea but will take extra work and can only be placed in layers of about.5" at a time. I have a small room 12x12 that I use as an office that has about a 2.5+" drop to one corner. The closet door has at least a 2+" gap at one corner. My son and I have studied all our options for a fix as the floor is very unlevel. Our game plan is to level the entire floor and place stone/slate tile over the entire surface. It now has a wall to wall carpet. Good luck on your project.

 

[truckemup97]

Avaire Interlocking Floating Porcelain

This stuff can be used in a flexible or not quite level situation. You might have to level some, but not as much.

Question: Would the thin set adhere to the concrete if you 1) roughed up the surface, and 2) used a concrete bonding agent?

 

[duketbrd88]

Trust me, just use self leveler. That stuff is excellent. I have done tons of ceramic jobs with it.

 

[Rugskipper]

Concrete is porous, and as such, exudes a certain amount of water vapor. Thinset with hardibacker is nearly a sure bet to induce mold underneath in the future.
Avaire is good stuff, I sell it. Pricey, but worth it to the DIYer when installing over wood substrates and skipping the whole underlayment gig.
I'd still use the self-leveling floor compound first. Then you'd have a level floor, and could use regular tile or porcelain without a second thought.

 

[ridewv]

I would lay a 1 1/2" thick board at your doorway, as a form, then use a self leveling cement such as Ardex K-15. It can be poured up to 1.5" at one time (5" if you add pea gravel.) You're going to end up with that step-up but at least your floor will be level.


Ardex K-15:
Portland cement based
High strength - 4100 psi
Installs up to 5" thick
Designed specifically for fast leveling of floors
Use to level and smooth interior concrete, terrazzo, quarry and ceramic tile, cutback adhesive residue (non-water-soluble), wood, and metal
Walk on in 2-3 hours
Install floor covering after 16 hours

 

[Rugskipper]

If you have carpet outside the bathroom door, you can always pull it back and use a shim to ramp the carpet up to the door, thus eliminating the step up.

Carpet Shims to do the flooring transition right!

 

[Strato]

I would dry pack and use marble or ceramic tile and cap the edge at the door with the same tile if there's a drop to the carpet.