kerdi over plaster question

[steronz]

Be gentle, I'm new at this.

I'm going to convert a closet into a shower. My house is from '28, and the bathroom is almost all original. The plaster in the closet looks to be in good shape. After some initial research here, I'm liking the idea of doing the whole thing in Kerdi. I'll have to knock some giant holes in at least 1 wall to run the water pipes up. I'm guessing I could patch the holes with cement board and cover the whole mess with Kerdi, but I'm way out of my element on this one. I'm worried about having lumpy walls, or an insufficient water barrier, or any other problems. This shower will sit right over my newly remodeled kitchen, so the last thing I want to do is have this thing leak, for several reasons.

The other option is to gut the whole closet down to the studs and start with fresh drywall or cement board.

Also, could I install a Kerdi shower tray directly over the hardwood floor in that closet, or should I take it down to the subfloor?

Anyone have any thoughts?

[Houston Remodeler]

Greg,

Welcome to the forum,

Optimal would be to take the room down to the studs. That will give you the best substrate control, the flattest walls and the plumb-est walls. You'll be adding a vent pipe for that shower somewhere right?

Tell us a little more about the flooring in that area of the house. Run the joist measurements through the 'deflecto-lator' linked in the blue bar above. You'll find if the floor can support tile or needs to be beefed up. What is the plywood? how thick?

Got pics of the area? We like pics. Some closer, some further away.

[steronz]

Thanks for the reply Paul. I've attached some pics of the bathroom and the closet in question. I plugged the joist measurements into the calculator and it said I was good to go. The house is a bit creaky but they certainly didn't skimp on the lumber.

I had planned on ripping down the ceiling, replacing it with drywall, and installing a light/fan combo that I can vent to the roof. Above the closet is unfinished attic, and we had our electrician put in a circuit for this that's sitting up there waiting for me.

The floor is just 3/8" hard wood over the original floor boards. Based on what you're saying, my first step is probably going to be ripping out all the plaster and pulling up the hardwood floor. I can post more pictures then. I have a friend with drywall/framing experience who said he'd help me with the next step.

[Houston Remodeler]

Greg,

That tub is great. I am sure you can find someone who wants it on CraigsList, or through a local historical reclaiming center.

You might also be able to get rid of that bump out behind the toilet. Ask a local plumber if the code has changed allowing you to make the vent pipe thinner than the 4" cast iron stack that's probably hidden in that cavity.