Curbless shower

[Saltworks]

I have been reading this forum for a while, and I have read the entries in the liberry on curbless showers and I have read John's book. I have a question on a handicap accessible shower I am currently building.

The bath is tiled with 1 inch mosaic tiles over a mortar bed. I have removed the existing tub/shower combo and have expanded the bath area into an adjacent closet, making an area about 5 feet by 5 feet where I will place the new shower. At the back of this space I am lowering the floor joists by 2 inches in an area that measures 3 feet deep by 5 feet wide. This area will get a mortar bed and Kerdi shower (thanks, John, for writing your book, and thanks to all in this forum for making this project seem doable).

Here is my question: I will be left with an area between the recessed shower bed and the existing tile that measures 2 feet deep by 5 feet wide. I believe I have two options. One - remove the old tile and mortar bed and retile the entire bath with Ditra. Two (and this may seem odd) - leave the existing tile and mortar bed in place, and transition between the old tile and the new shower. I thought that perhaps I could slope from the exisiting tile (it's between 1 inch and 1.25 inches above the subfloor) to the recessed shower to decrease the chance of water escaping from the shower pan. I wouldn't attempt to match the old tile - I would just select a new tile for the shower that would clearly define the new shower area. I don't know if this sounds feasible and I am looking for opinions. I know that the new tile would have a "cold" joint against the old mortar bed and I don't know if that would be a problem.

Thanks in advance for any advice.

Bill

[Airborne]

If you don't want to replace the remaining tile, my approach would be to build up the area between "old" tile and new shower with a "preslope" of sorts and install the Kerdi as you described, starting at the old tile.

As for the "cold joint" I'd caulk the joint to allow for movement between the old and new assembly.

[Saltworks]

Art

What would you suggest I use for a preslope? The slope would taper from about 3/4 inch to a feather edge at the beginning of the recessed shower pan. I know that's too thin for mortar. Would modified thin set work?

Bill

[muskymike]

Hi Bill, welcome. You don't want to use thinset there for the slope, you want to use deck mud. Check out the Liberry and go to shower construction for the mud recipe. Also I think that area that you said it 2 x 5 should either be removed or you can go over it with the ditra if the tile is sound. You want to have the whole floor waterproofed if it's going to be handicap accessible.

[Saltworks]

Mike

I will be using deck mud for the shower pan slope, but the slope on the 2 foot by 5 foot section of floor in front of the recessed shower portion is not tiled and will slope from about 1 inch (the height of the existing tile) to almost a feather edge (where it meets the recessed mortar bed for the shower). I was under the impression that a mortar bed had to be at least an inch thick over plywood, so I was looking for options other than deck mud. If deck mud will work, I will use it, but I want to be sure it can be laid that thin.

Bill

[cx]

Welcome, Bill.

If I understand the situation, I don't think you can do what you are describing. I think you would need to slope the subflooring such that you could have an absloute minimum of a 3/4 inch mud bed on that entire sloped area. I personally don't think less that one-inch is enough, but I think the industry standard would be 3/4 in your application. I just don't see a way for you to taper the mud/thinset down to zero on a wood subfloor and hope to have a successful installation.

Maybe a good picher - we like pichers - or a drawing would help if I'm not understanding the situation.

My opinion; worth price charged.

[Airborne]

Hmmm....guess I mis-imagined the situation.

[Saltworks]

CX

I was afraid I couldn't do what I was thinking of doing. I was wondering if there was a product that would allow a transition from 3/4 inch to nothing with Ditra and tile over it. Sounds like a tear off is the only solution.

Bill

[John Bridge]

Welcome aboard, Bill, and thanks for buying the book.

What I'm wondering is why you didn't depress the floor in the entire 5x5 area. What's wrong with doing that and simply meeting the existing tile and mortar bed at that point?

Maybe we need you to post a picture or two.

[Saltworks]

Actually, John, that's an excellent idea. I have sistered the joists for their entire length so that may be possible. I was only thinking of the actual shower area, not the approach, when I started. I will see if the building inspector will approve the larger area of joist height reduction. I will try to get some photos to post.

Thanks

Bill