Different kinds of backer board for shower

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RCraig

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I have heard all kinds of ideas and opinions about the various kinds of backer board for a shower surround.

Yesterday I saw "Wedi" board (not sure I have the right spelling). It is a foam board, and is rubberized on each side. I like the idea - very light and hopefully water-tight.

Any opinions?

Thanks again,

Still without an upstairs bathroom but there is hope in sight.
 

Jadnashua

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First, a typical cbu (cement board) is not waterproof, but it is not damaged by being wet. It was developed as a fast way to emulate a mudded wall (still superior and still used). There are a couple of different classes of that board - all cement and fiber-cement boards, that have slightly different installation requirements.

There are at least a couple of tileable foam panels out there, and Wedi has probably been around the longest. The coating on either side is waterproof, and thinset friendly. The other one I know of is KerdiBoard. Either of those can be used in place of cbu on the walls of a shower (and Wedi has shower pan panels that tie in as well). Schluter, who makes KerdiBoard, can tie the boards with their pans as well - some of them come already waterproofed, some require you to add the sheeting yourself (all of them, eventually will come covered). The methods of waterproofing seams differs between companies, and must be followed for a successful result.

Both of those two manufacturers have been in business for a long time, and their products work if you install them properly.
 

JohnfrWhipple

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My thoughts.

Foam boards suck.

Durock is the crappiest of all cement boards.

Hardy Board is crap.

WonderBoard Lite. I like it. It is the only backer board I currently recommend. In Vancouver Super Panel is a good choice, but leave your panties at home since it's heavier than Wonder Board lite.

I have never used Wedi Board so I can not really give an opinion. My opinion of foam based board was formed after "Garage Testing" "Blue Collar Style" Kerdi Board. Kind of scary that the board uses some kind of cardboard or pressed paper to give it strength....

I'd tell you about the testing I did with three niches made from a foam based backer board. But I'm careful now a days with what I say about certain products. Lets just say 2 pf the 3 niches failed my private NON APPROVED GARAGE STYLE BLUE COLLAR TESTING - I was so silly. I filled them with water and left them more than 2 days. And when I did this I did not know what incredible pressure 3.5" of water has.... LOL What's funny men is that the one that did not leak finally evaporated about ten days ago. You men remember when I started that. The other two did not make a week..... But lets be clear. A waterproof niche does not get filled with water. And the testing should include grout and tile. Of course.

Do not fill any niche with water to check if it is waterproof - that's crazy! LOL
 

Jadnashua

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Wediboard has been on the market, at least in Europe, for 25-years...so, people have been using it...if it truly was junk as some think, I think they'd be out of business by now. Schluter wanted their board to provide superior properties, an expanded use profile, and for the market to become more amenable to its use, so they took their time before they introduced KerdiBoard. As with anything, you have to use it as designed, and an understanding of how it works is important to make any viable evaluation.

Both of those boards are part of a shower system, and each has their specific requirements on how it must go together, and they each have their restrictions on how it can be used that should be understood. Both WediBoard and KerdiBoard can be used outside of a shower where you need a panel to tile onto.
 

ShowerDude

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Gotta say Johns point is valid. I took his advice and have also gone back to wonderboard lite. i do believe durock nextgen has gone downhill from a consistency standpoint

Foam? I will only use Wedi. .... But i am hoping to try hydroban board soon..

wedi board is super stiff rigid and fiber cement coated on both sides...you cannot compare other foam boards to it. i have used the orange foam. Absolutely a weak wimpy material IMO.

But again im a cement pan cement board wall kinda guy.

John just for reference get your hands on a sheet of 1/2" wedi board.. i think youll be impressed at the quality/ structural

properties...

depending on your situation a wedi backer with wedi sealant is going to install quicker and will save time as well , its just damn expensive!

Show us your progress photos....
 

JohnfrWhipple

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Counter - I tried years back. Had some good chats but when I tried to get training from Wedi it was like pulling teeth. I can only try so hard. If it is that hard to get training then I can only image the problem when you need help for a serious matter.

I know guys like it - I just hate foam backer boards. Well - I hate Kerdi Board.

Durock's board is so dry. I bet it is adding to lighten of tile, grout and a dare say efflorescence. But what do I know. I tried to test a waterproof niche with water.... Silly me.
 

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Durock & Efflorescence that is a good question , a very valid question, most mfg' now claim " does not contribute to efflorescence " in sales jargon and i must say its grabbed my attention... Just today i had to explain efflorescence to a client... Its a tough one to explain to the end client.


Doubly hard to explain to a GC. That wants to grout to soon, and keep sponging haze off!!!

Hurrying dry times = Long odds gambling!!!
 

JohnfrWhipple

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Counter Balance.

Try setting some tile on Durock. Half with no waterproofing over it and half with. Then Grout it. Then sit the sample in water.... I wonder what happens... ?

I have been meaning to mock this up, but no time.... Maybe if I stop blasting Jim I could find the time..
 

RCraig

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Show us your progress photos....

Unfortunately, no progress at the moment. Major problem is that the tiler needs strapping to be put on the studs, which he wants a carpenter to do. The reason for the strapping is so that the backer board on the front side of the tub can come down over the flange. The tiler feels that Wedi coming down over the flange will be very resistant to leakage in the future.

Thanks for all the thoughts about backer board. By the way, I read a lot about flood testing (for resistance to water). Should one flood test a shower surround, which is what my project is? I mostly read about it in references to showers that have a pan.

THanks, Ruth
 

JohnfrWhipple

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Ruth - You only need to flood test the tun and tub overflow. Typically for a period of 12-24 hours.

The weak link is where the tub meets the backer board. This detail is the one you need to worry about.
 

RCraig

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Ok, thanks for your prompt reply. Might I ask how one goes about testing this? Run the shower for a while, pour water on the interface between the tub and the backer board? Not sure what is meant by a flood test, sorry.
Ruth
 

Jadnashua

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In a shower, you plug the drain and fill the pan with water, then wait to see if the level drops (other than from evaporation) or evidence for leaks. You do this before you add the tile, right on top of the liner. Generally, it's pretty easy to verify that it is water-tight.

On a tub/shower, you cannot literally flood it. There, assuming you have a proper tiling flange on the tub, the tub is installed level, the potential weak points in the tub itself are the drain and the overflow. You can fill the tub with water and try to go above the overflow and see if you get anything behind it, or underneath it.

On the tub/wall area, it's more of a good workmanship, quality materials situation. If you deal with that, with the tiling flange, and proper materials and workmanship, water will not get behind the walls. It depends on the materials you choose, the best way to handle that area. If you are going to use Wedi, have you looked at their website to see how they recommend doing it? That would be the first place I'd look.

To see how you'd do it with KerdiBoard, start at page 32 of this http://www.schluter.com/media/shower-handbook.pdf?v=201406040601 . Wedi probably has a similar document describing how they want their material installed.
 

RCraig

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In a shower, you plug the drain and fill the pan with water, then wait to see if the level drops (other than from evaporation) or evidence for leaks. You do this before you add the tile, right on top of the liner. Generally, it's pretty easy to verify that it is water-tight.

On a tub/shower, you cannot literally flood it. There, assuming you have a proper tiling flange on the tub, the tub is installed level, the potential weak points in the tub itself are the drain and the overflow. You can fill the tub with water and try to go above the overflow and see if you get anything behind it, or underneath it.

On the tub/wall area, it's more of a good workmanship, quality materials situation. If you deal with that, with the tiling flange, and proper materials and workmanship, water will not get behind the walls. It depends on the materials you choose, the best way to handle that area. If you are going to use Wedi, have you looked at their website to see how they recommend doing it? That would be the first place I'd look.

To see how you'd do it with KerdiBoard, start at page 32 of this http://www.schluter.com/media/shower-handbook.pdf?v=201406040601 . Wedi probably has a similar document describing how they want their material installed.

Ok, thanks. The water is not hooked up to the new tub at the moment, waiting for the carpenter and then the tiler to do their things. However, it seems as if I could fill the tub from another source and see whether the water level decreased after 12-24 hours, and whether any leaking was seen. Does that sound like a good idea to you?
Ruth
 

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Ruth.... have you considered hiring a pro tile guy to help you?

If he cant fur the wall out proper , that comcerns me of skillset?


You can seal your backer at tub flange with 100%silicone.( if waterpoofing walls or using a foam board)

If you do use wedi or the orange board you can use their sealant.

Jim??? You made it a day or 2 and right back to the orange links!

Well, you tried and i know it must be hard, after all you are a graduate student Orange Alma/mater.

Im thinking either you should drive over to Ruths and do a site visit and save the day.....Or is she already at your place? Wife? Friend? Fictitious poster like me??
 
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Jadnashua

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The stoppers on many tubs leak a bit, but it just goes down the drain, not out into the space. Some tubs require the drain to be installed with silicon, some want only plumber's putty, some do not want putty (depending on the type you use, it may stain the tub from the oils...there are 'stainless' plumber's putties, but I don't know how well they work). On the bottom of the tub where the drain goes, some of them are really rough, and you can't get a good seal with just a gasket, you need to use something like silicon. So, it's hard to say without seeing your tub itself or the drain and the instructions for it. But, yes, you could fill the tub, close the drain, and look underneath periodically to see if anything is leaking other than down the drain. You could create a wave and get water above the overflow and see if it leaks there. Same issue...sometimes the area around that hole is not smooth, and just a gasket won't work well.

As to the Wedi, depending on the thickness of the tub's tiling flange, you may just be able to notch the back of the WediBoard so it can sit flush over that flange, rather than shimming the wall out. Shimming the wall out means another step to make the tub-rest of the bathroom look good if that wall is now thicker plus the thickness of the tile. Having seen how they put their showers together, my guess is that they'd suggest putting some of their special sealant along the vertical part of the tiling flange, and a bead right at the corner of the horizontal/vertical of the flange, and embedding the board into that, but that's a guess, you really should check out their website to see how they recommend it be done. Their sealant is not silicon, and while that may work, if you're using their board, the installer will need some of that sealant anyway if it is installed properly, so I'd just use that at the tub/wall seam as well. The stuff is not inexpensive, but is designed as a permanent waterproofing seam for use with WediBoard.
 

RCraig

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The stoppers on many tubs leak a bit, but it just goes down the drain, not out into the space. Some tubs require the drain to be installed with silicon, some want only plumber's putty, some do not want putty (depending on the type you use, it may stain the tub from the oils...there are 'stainless' plumber's putties, but I don't know how well they work). On the bottom of the tub where the drain goes, some of them are really rough, and you can't get a good seal with just a gasket, you need to use something like silicon. So, it's hard to say without seeing your tub itself or the drain and the instructions for it. But, yes, you could fill the tub, close the drain, and look underneath periodically to see if anything is leaking other than down the drain. You could create a wave and get water above the overflow and see if it leaks there. Same issue...sometimes the area around that hole is not smooth, and just a gasket won't work well.

As to the Wedi, depending on the thickness of the tub's tiling flange, you may just be able to notch the back of the WediBoard so it can sit flush over that flange, rather than shimming the wall out. Shimming the wall out means another step to make the tub-rest of the bathroom look good if that wall is now thicker plus the thickness of the tile. Having seen how they put their showers together, my guess is that they'd suggest putting some of their special sealant along the vertical part of the tiling flange, and a bead right at the corner of the horizontal/vertical of the flange, and embedding the board into that, but that's a guess, you really should check out their website to see how they recommend it be done. Their sealant is not silicon, and while that may work, if you're using their board, the installer will need some of that sealant anyway if it is installed properly, so I'd just use that at the tub/wall seam as well. The stuff is not inexpensive, but is designed as a permanent waterproofing seam for use with WediBoard.

Ok, thanks so much. I am learning. I will ask the plumber about flood testing as you suggest.
About shimming out the front wall of the tub - this may actually help matters out in terms of making the rest of the bathroom work out. The reason is that the wall at the front of the tub had to be moved back about 1.5 inches. The reason for this was to fit the new tub in. So, the carpenter is talking about 1/2 inch strapping. The tub flange is at least 1/4" deep. The foam board, although 1/2", does not seem a whole lot thicker than the flange. So the shimming out might be good in that respect as well.

For the people from other states, New Hampshire is actually a pretty large state and I live kind of out in the boonies.

Many thanks again, Ruth
 
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