Urgent Problems Converting Tub To Walk In Shower

I'm working with someone who has taken on every aspect of re-modeling my son's bathroom. We were nearly finished but have to undo a few things and start again. I need advice to make sure this time we cover all our bases.

The floor under the tub that was removed is the concrete foundation of my house. After taking out the tub, he extended the drain, cutting into the concrete about 3 inches and tiled directly over the concrete with no pan installed, pitching the tiles so that the water would ideally flow to the drain area.

It appears from pictures of the process that the extension of the drain wasn't positioned correctly. It slants upward to connect to the original bathtub drain hole. I've been told he needs to cut deeper into the concrete and make sure the extension is slanted downward 1/8 of an inch.

We're removing the tiles tomorrow to fix the drain and lay the shower liner which we’ll make into a pan. I don't want to remove the bottom row of 16x16 slate tiles on the shower wall so I think we will have to dig the entire floor 3 or 4 inches to be able to lay the liner and create the lip of the pan around the 3 shower walls. I've been told to create a 12" lip along the wall, but I really don't want to waste those tiles and figured 3 -4" would be good enough.

Some people have said to just lay the tile with no liner. Most people say you have to use a liner or else the foundation gets soft from water leaking through the tile and/or water can seep into the bedrooms. I was thinking we could avoid using the pan and digging up the concrete if we could get a hold of some sort of concrete sealer or marine cement to put on top of the existing cement but the plumbing supply store I went to today didn’t know anything about it.

Also, when we raised the water controls from bathtub height to shower height and installed the new handle, the hot and cold water is reversed. I saw on one post that may be due to the cartridge being in backward. I'm not sure if that's the case here or if it was like that when it was a tub.

Please advise asap... we're starting the un-do/re-do first thing in the morning.

Thanks!!!

If there's no pan liner... there's no membrane in the wall, either, is there?

So don't bother trying to save the bottom tiles. You have to rip out & redo the walls, anyways.

National code requires a waterproof layer on a sloped bed for a shower. Whoever tells you otherwise is a hack. Tile is not to be considered waterproof. the membrane should be applied so that it extends at least 3" (and most pros go further) above the top of the curb. You are supposed to block the drain and do a leak test (often overnight) to verify it is intact and no water is lost.

You may have other problems, especially if this is getting inspected (sounds like it isn't)...a tub usually has a 1.5" drain, a shower requires a 2" drain.

If you want to learn how to do it right, check out www.johnbridge.com.

too late to help you much now. Lots to learn -- and it will take the time it takes.

Lots to ask, lots to answer.

David

thanks for replies

thanks for the replies everybody... we're going to dig the concrete down 4" and run the pan up the wall to meet the bottom row of slate tiles that are installed. That ought to work right? what can I tell you, this is definitely a learning experience. at least we're taking the steps backward to make it as right as possible.

I bought floor mud to put on top of the liner to re-build the floor to put the tiles on top (using thinset to set the tiles) are we supposed to put anything under the liner to bond it to the dug-up floor or will the mud on top suffice?

Any tips appreciated...

Sorry for not asking before we began but these were things it never occured to me to ask

The best way to do a traditional shower pan with cbu on the walls is to do the preslope, then the liner with the studs notched to allow for the thickness of the folds in the corners, then install the cbu with some thinset mushed behind it and screws only down to the top of the liner, then put the top layer of mud down that ultimately, the tile will be set onto. You can't nail into the liner to hold it, except at the very top (above the height of the curb by say 3" or so), or you've just created a leak point. You can't nail the cbu down low because again, it puts holes in your liner. So, the top layer of mud holds the cbu tight against the walls, trapping the liner in place.

WIthout putting the liner up the wall above and over the curb, you are going to get moisture into the walls and the curb. It will fail. How long will depend on how often you use it. to do it right, you need to remove about the bottom 12" of the wall-tile to put in a proper liner, then rebuild. You need the liner to go over the curb, then some lath, then some fat mud then the tile.

There's a very good article and a wealth of info that all meets the national codes on shower construction at www.johnbridge.com.

Thanks... I will check out that site! I appreciate your information! Robin