Tub removed, bringing out new questions/issues

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Jadnashua

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IF you are going to use the tub as a shower, industry standards call for tiling and water/vapor management at least to the height of the shower head, and some prefer to go all the way to the ceiling. If you're going to use a membrane in a shower, go at least that high with it. Most of them are not designed to be painted, so you'd stop it and the tile, with none sticking out.

If the tub does not also have a shower head, then it is only important to ensure you get the tub itself sealed to the wall, and then go up the wall at least a few inches (more certainly doesn't hurt). But, without a shower head, we're only taking about maybe some splashing up the wall, and there shouldn't be enough to soak into the wall behind and create a problem through the tile and grout (although, it certainly doesn't hurt).

There's also the option of using something like KerdiBoard or WediBoard instead of cbu on the walls of the surround which are both structural panels and waterproof that are designed to be tiled to. I've used KerdiBoard, I have not had a good chance to deal with Wedi products yet, although I did consider it on my last shower. CBU is not waterproof, but it is not affected by being wet and is a good, compatible surface to tile to. Getting a tub/wall waterproof seam with it is possible, but you need to be careful. ANohter big thing with water on any tub is to ensure it is level in both directions, otherwise, it can flow where you don't want it, or pool, and then soak the materials, depending on what you have there.

There are liquid and sheet membranes, pick one, and follow the manufacturer's instructions to the T, and it should work fine and you'll get a warranty from them. Most of them are at least 10-years, some longer, but if a problem doesn't show up in 10, it probably isn't going to happen.
 

RCraig

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Ok, thanks for the advice, yes, there is a showerhead. The tile goes up to about the level of the showerhead. This bathtub is actually usually used for showers. The whole reason it is in the process of being replaced is because there used to be leakage down into the basement when someone took a shower. I am hoping to to repeat this situation. That was the reason the UTube on Kerdi Membrane was so interesting.

In the UTube video, they showed 2 different possibilities:
1. the board on the wall surrounding the shower lapped over the flange of the tub.
2. the board on the wall surrounding the shower came down to the flange but not over the flange.

Which of these might be preferable?

Also, if one puts the KerdiBoard (or WediBoard, or Hardibacker is what the tiling guy is thinking about) such that it comes down over the flange, wouldn't it flare out at the bottom where the overlap is?

Thanks! Ruth
 

Jadnashua

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If you don't prep the walls properly, yes, if you go over the tub flange, it will flare out and give you problems. You don't need to get it down over the flange, but if you're using say a cbu, you must put a vapor barrier behind it and lap that over the tub flange. If you use cbu and are using a small tile, you do want the cbu to come down most of the way (some tiling flanges are quite wide). To do that, you either notch the studs and recess the tub's flange into it, or put some shims on the wall and that brings it out enough to go over the flange.

If you use something like Kerdiboard or Wediboard, they're easy to notch the back so you don't need shims on the wall or to notch the studs.

Keep in mind, there are two classes of cbu - some called fiber cement boards (like Hardiebacker) that contain some actual fibers (cellulose in this case). They contain mold inhibitors and are still quite stable. THen, you have true cement boards, that do not contain any organic material (FWIW, they usually aren't as strong). In either case, though, you normally do not let the cbu, whatever type, touch the horizontal surface of the tub, you hold it up a bit, then caulk that seam.

Personally, I like some of the profiles that can be used with tile that negate the need for any caulk in them at all...industry standards call for caulking any seam between differing materials or changes of plane (i.e., corners). With engineered joints, you don't need caulk. I think they're neater, and require much less maintenance in the long run. At least several companies make them, but www.schluter.com was one of the originals in the industry, and has a really wide variety.
 

RCraig

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Oh wow, thank you so much for this information. They didn't notch the studs. The studs come right up to the tub. They are going to use Hardiebacker. If I understand correctly, they have to put a vapor barrier ?behind the hardibacker?
Here is my level of lack of understanding - What is behind the hardibacker and the vapor barrier? right now all I have is the studs. The studs come right up to the tub. Does one put up something on the studs (a wall in layman's terms) and then put the Hardie backer on that?

Since the studs aren't notched (because the thought was that was the cause of the previous leak), am I correct in my interpretation that I need "shims"?
Much appreciate your help.

Live Free or Die!
Ruth
 

JohnfrWhipple

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I would use some Ardex 8+9 on your install and go with a topical waterproofing approach.

Or perhaps you can use Hydro Ban from Laticrete.

Maybe some Red Guard???

Perhaps Wall Seal from Noble Company set with EXT?

Just make sure the waterproofing approach you use allows for modified thin-sets. That is the single most important consideration since these thin-sets are preferred by most tile installers and most tile manufactures.....

Do your homework. Go with the masses instead of the advice from just one or two posters. Check with the many different manufactures and confirm that the industry norm is to use quality modified setting materials.

If you decide not to waterproof the tub shower with a topical approach (like the Ardex 8+9 shown above) this step make sure the poly gets sealed to the tub flange with a little silicone.....
 
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RCraig

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I think my problem is that I don't really understand how to manage the interface between the Hardibacker and the tub. Should the Hardibacker come down just to the top of the flange? Or should it come down over the tub flange such that the tub flange is not visible? Very worried about this because the leaking in the past came from the edge at the front where the tile wall meets the tub.
Thanks so much, may I ask what that is on the lower right of the picture you kindly uploaded. It looks like some kind of tape (maybe about 2" wide) near the tub/wall interface.
Ruth
 

Jadnashua

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It depends somewhat on the size tile you are planning to use and how tall the flange is...if more than half of the tile is being supported by the cbu, you can stop the cbu above the flange. Or, you can shim the studs out so that the cbu will be able to go over the flange. Or, you can notch the studs so the flange is now flush with the studs, and run the cbu down there. You should leave a gap between the bottom of the cbu and the horizontal surface of the tub. Depending on the waterproofing method you use determines how it interfaces with the tub. If you're using no surface waterproofing, you'd run your vapor barrier down, over the tub flange and then seal it to the flange. Using a surface membrane, it depends on which one you use, how you seal the tub/wall junction. So, you need to determine that for more specific advice. And, each manufacturer will usually discuss this in their instructions, sometimes they'll also have a video or two showing you the technique. While some (John) now will do anything to get people to not use Schluter products, they have been in use since the 1980's, and I feel, work fine. This is one of their videos doing what you want so you can see the technique. Most of the surface membrane sheets will be similar. Liquid membranes will be different. FWIW, KerdiFix is a really good sealant, will cure underwater (you could use it to seal a leak in a vinyl above ground pool without draining it), and is a critical seal when using their system at the tub.

Just, don't get it on your hand or anywhere else you don't want it, as it will be there for awhile if you let it cure a bit!
 
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JohnfrWhipple

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[video=youtube_share;OODB_RyxJm4]http://youtu.be/OODB_RyxJm4?t=26m40s[/video]

Hilarious Video. I especially like the comments about his opinion of the "S" products 26:40 Start.... OMG That is funny

I like the use of blocking.

Did not like the way the tub was pinned.

Did not like the lack of vapour barrier. Might not be required in Atlanta... ???? not sure.

I like my way better....
 
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RCraig

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"I like the use of blocking.
Did not like the way the tub was pinned.
Did not like the lack of vapour barrier. Might not be required in Atlanta... ???? not sure.
I like my way better.... "


Do you mean the blocking right behind the tub flange? I was wondering whether I should have that done. It would be a bit tricky on the front side of the tub (where I previously had leaks and am paranoid about) - because of faucets in my case.

Would it be possible to get an impression of the key points of your way that I should make sure to pay attention to? As far as vapor barrier, one of the short walls of the enclosure is an exterior wall in my case, so there is a vapor barrier. No vapor barrier on the other 2 walls at the moment. I went to Walmart to look for the kind of board he had - because it has a vapor barrier on the back of the board. Unfortunately, they didn't have that kind of board, only Wonderboard Lite.

R
 

JohnfrWhipple

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"I like the use of blocking.
Did not like the way the tub was pinned.
Did not like the lack of vapour barrier. Might not be required in Atlanta... ???? not sure.
I like my way better....


Do you mean the blocking right behind the tub flange? I was wondering whether I should have that done. It would be a bit tricky on the front side of the tub (where I previously had leaks and am paranoid about) - because of faucets in my case.

Would it be possible to get an impression of the key points of your way that I should make sure to pay attention to? As far as vapor barrier, one of the short walls of the enclosure is an exterior wall in my case, so there is a vapor barrier. No vapor barrier on the other 2 walls at the moment. I went to Walmart to look for the kind of board he had - because it has a vapor barrier on the back of the board. Unfortunately, they didn't have that kind of board, only Wonderboard Lite.

R


He had no vapour barrier on the back of that board from what I saw. The board he was using was Denshield. I think his install is flawed. A quick phone call to his local city hall I'm sure would have informed him that vapour barrier was needed on that long five foot wall and perhaps one of the short ones.


Wonderboard Lite is my favourite backer board today. Great product.

"I like the use of blocking.

Blocking is king in my world. No flex. The area where backer board meets the the tub (up a bit) is prone to flexing.

Did not like the way the tub was pinned.

I prefer window clips wrapped in electrical tape.

Did not like the lack of vapour barrier. Might not be required in Atlanta... ???? not sure.

Local code trumps all. If a vapour barrier is required and not installed throughout the year moisture will be condensing on the back of that board. Not good.

I like my way better.... "

I like my way better because I do not pin the tub with a rigid nail or screw. I have solid backer. My waterproofing wraps up behind the backer board and down over the tub lip. Then the wall waterproofing ties into this. Completely sealing the backer board to the tub - yet giving it a little room for expansion at the same time.
 

RCraig

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He had no vapour barrier on the back of that board from what I saw. The board he was using was Denshield. I think his install is flawed. A quick phone call to his local city hall I'm sure would have informed him that vapour barrier was needed on that long five foot wall and perhaps one of the short ones.


Wonderboard Lite is my favourite backer board today. Great product.

"I like the use of blocking.

Blocking is king in my world. No flex. The area where backer board meets the the tub (up a bit) is prone to flexing.

Did not like the way the tub was pinned.

I prefer window clips wrapped in electrical tape.

Did not like the lack of vapour barrier. Might not be required in Atlanta... ???? not sure.

Local code trumps all. If a vapour barrier is required and not installed throughout the year moisture will be condensing on the back of that board. Not good.

I like my way better.... "

I like my way better because I do not pin the tub with a rigid nail or screw. I have solid backer. My waterproofing wraps up behind the backer board and down over the tub lip. Then the wall waterproofing ties into this. Completely sealing the backer board to the tub - yet giving it a little room for expansion at the same time.

OK, maybe I will request that they use Wonderboard Lite. The thing was, some of the sheets I saw when I went to HomeDepot seemed to be crumbling.

The area where the backer board meets the tub/flexing. I believe this has been the problem that has been plaguing me for a long time, and the reason I had to have the tub removed, the floor replaced, and have been without an upstairs bathroom for about a month. My hypothesis is that flexing with people taking showers eventually led to loss of integrity of the silicon or whatever was in there. Then all the caulking I was doing was just a bandaid.

Curiously enough, the plumbers screwed the new tub to the studs on the long side and the back. Screws actually go through the flange.

I like your idea about the vapor barrier at the back of the board, then, if I understand correctly, being sealed to the flange. Is it adhered to the flange and if so, what do you use? I am also thinking that Canada is a lot different from Georgia in terms of weather, which might be part of it.
 

Dhagin

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... I am also thinking that Canada is a lot different from Georgia in terms of weather, which might be part of it.

This is true, and regional differences necessitate various construction details. :)
 

RCraig

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If you know any amateurs, the video is really very good, although some of the thoughts may relate to specific climates.
 
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