Ask Me Help Desk - WaterPROOF shower walls.

I have demolished and prepared the floor under my shower and bathtub. In short I am looking for the BEST method and materials for vapor barrier and WATERPROOF wallboard to install undeneath the tile finish. I am using a premium shower pan with a lip around three sides to accommodate the sidewall materials. I am looking for the absolute best installation without floating the walls and hot mopping the pan. This is an upstairs master bath, and I want to avoid any leaks in the future. Thanks in advance.

Your pan description sounds like a "Tile-ready" pan?? If so, their would be no hotmopping as the pan get's tile bonded to it with the included laticrete epoxy. If you got some other products, post back with the name.

For your walls, Kerdi or Nobleseal TS will waterproof and vapor proof the substrate prior to tile. Either membrane would be installed overlapping the side of the tile ready pan and sealed to the side of the pan with Kerdifix for Kerdi walls or Noblebond for TS walls. Kerdi over regular sheetrock or TS over cement board.

If you want to waterproof your floor as well, Nobleseal TS can be thinsetted to the floor and flashed up the walls a little bit, or you could use Schluter's DItra and for the seams of the Ditra, seal them with Kerdiband, which is a component of the Kerdi waterproofing system. Either of those membrane systems would be used in place of and provide better performance than a cement board on the floor.

You could install the cement board of your choice as well and then use any of the trowel on/roll on membranes. Since you are in California (as guessed by the comments about floating out walls and hot mopping), then Redgard should be readily available as Custom building products is a California company.

Noble Sheet Membranes & Shower Installation Products for Tile & Stone

Schluter Schluter Systems - Homepage - Schluter-Systems

If you can return the shower pan, do so and use the entire shower system from either Schluter or Noble company

Both systems 100% waterproof and vapor proof and on their own for the complete system, from drain to top of the walls, are usually less than the excessive cost of just the tile ready pan.

If you have any exterior walls with this shower, you cannot have any sort of vapor barrier over the wall framing and you must use unfaced insulation behind either of these vapor proof membranes.

I guess I should have been clearer. The pan is acually a pre fab shower floor. It is a top of the line American Standard.

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I guess I should have been clearer. The pan is acually a pre fab shower floor.

I wondered that, but the tile ready pan has a sidewall to start the tile walls. Once you said hot mop, I figured tile pan because that is a method of creating a waterproof pan layer on site built custom pans to receive tile and stone.

The same guidelines apply for the shower walls for waterproofing, even with your preformed pan. Kerdi or Nobleseal TS are your best options for water and vapor proofing the walls. Stop the cement board about 1/8" above the flange, seal the membrane to the flange as instructed in the previous post.

For your drop in tub, it is best to use a waterproofing membrane over the tub deck and flash it up the walls a couple inches. Your walls can be whatever you want to use as that area is not considered a wet area but it will provide an extra layer of protection against future caulk failure and standing water on the tub deck that gets splashed out. The waterproofing membrane gives about 40 sf/gallon and can be rolled on or trowel applied.

Thanks so much for the detailed answer. This is a great site. Thanks again.

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Originally Posted by Bljack

If you have any exterior walls with this shower, you cannot have any sort of vapor barrier over the wall framing and you must use unfaced insulation behind either of these vapor proof membranes.

At the risk of hijacking this thread...

I am building a bathroom that has a shower immediately adjacent to a drop in tub, so the tub deck will regaularly get wet. The shower has one interior wall and one exterior wall. The drop in tub has a 2" 'lip' to the deck and a 6" 'shelf' on all 4 sides two of which butt up to walls, one interior one exterior. I intend to tile with 18" slate everywhere.

My current plan is:

For the shower:

1) build the shower pan using Noble CPE + pre-slope, reinforcing corners etc
2) staple 15lb roofing felt over the studs down to and overlapping the CPE
3) screw hardibacker board down to the shower pan
4) tile

Is this OK? What do I do with the outside wall bearing in mind the comment above? Is there a better way to go with the waterproofing? Do I need worry about the penetrations of the felt into the wall studs?

For the tub:

1) Frame out the box for the drop in
2) Felt the walls like the shower and bring the felt over the deck and down the side facing the shower (as per the walls)
3) screw hardibacker to the deck and walls
4) seal hardibacker deck with redguard
5) tile
6) drop in bath on top of tile with sealant between lip and tile

Is this OK? My hope is that water on the deck will not be able to penetrate through to the felt underneath, otherwise it can only run into the void under the bath.

I have recently moved here from Europe where bathrooms are all constructed with cement block for the walls and drop in baths use siporex (lightweight aerated concrete) for the structure so you have no issues with rot!

Thanks for your feedback, ideas and help. Right now I am looking at this job with significant worry!

Cheers,
Steve

3)

I am taking out the bathtub in my house and building a walk in shower. This is a very small bathroom with a small doorway. I can't get a one piece shower through the door and cutting a hole in the wall is not an option(/asbest siding on the house) and nobody will touch that! I need to find 3
Waterproof shower walls. I know they are out there, but where in Oklahoma?!

Lowe's and HD sell shower wall kits.

Does Durarock need to be "taped and or sealed" for waterproofing prior to tile being applied to shower walls? This is my 2nd shower redo by "professionals" in 10 years. During both demos the wall studs were rotten 3-5' from the floor. During this demo I learned the metal shower drain had never been sealed to the PVC sewer pipe.