Installing cement board behind my shower

Discussion in 'Shower & bathtub Forum & Blog' started by KatrinaK, Nov 14, 2011.

  1. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    John Bridge sends people here for plumbing questions, and I send them there for tiling questions...I don't get paid, just like there are more plumbers that deal here, more tilers congregate there. They push people to follow the TCNA guidelines, which is the bible on how to do things tiled. WHile here, you may get one or two opinions on a tiled situation, there you may get 10, and in an hour verses a day or more. So, it behooves everyone to filter out the junk, but there are enough reviews so that if there's an error, it gets fixed pretty quickly.

    And, in the examples you quoted, the problems were discovered during a flood test, and my explanation was why it occured - nobody was saying don't flood test. One reason Schluter specifies a minimum of a 2" overlap is to account for some errors...a properly done seam shouldn't wick more than 1/4-1/2", and if you have at least 2", it is still safe even if it wicks some as the result of marginal installation practices which may occur with a first-timer. There is generally little standing water, especially for 24-hours, so as long as it doesn't wick beyond the seam, it's still perfectly safe.

    In one class, they had Kerdied a cardboard box...this one had been in use for about 6-months and was getting kind of floppy, but it was filled with ice and drinks everyday, and by the end was mostly water....the cardboard was fine except from the flexing was no longer stiff. But, the Kerdi was still intact and bonded. The stuff works...other stuff works. Just like I drive a BMW, you may prefer an Audi...they're both good.
  2. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,173
    Location:
    North Vancouver, BC
    post(s) deleted by John Whipple
    Last edited: Mar 17, 2014
  3. mtcummins

    mtcummins In the Trades

    Messages:
    380
    Location:
    Pittsburgh PA
    Remind me next time I ask, to always find one of JW's showers to go swimming in.

    As far as non-swimming showers, I'll stick with Kerdi properly lapped (done as roofing is done, horizontally with overlap, not with band), and never once be concerned that it will leak... unless of course I decide to plug up the drain and try to go swimming in my 4" deep shower-pool. Even then, I don't have any concern that it will leak, but its a moot point, as this is not a real world situation.

    John knows his stuff and has his opinion. There are many other professionals who have a different opinion. Pretty much all of these waterproofing methods are valid when installed properly, so just install them properly.

    You'll probably note here that I'm the one who said to install kerdi on drywall (per manufacturers instructions), and that I just use VersaBond (knowing full well that this will void the warranty). If you're not comfortable with doing that, don't. Simple as that. I'm comfortable with the performance given using this method, and with voiding the warranty.

    John, a little more tact would be appreciated. You can feel free to express your opinions, but you don't have to be an ass about it. I'm offended on Jim's behalf the way you've responded to him. I respect your knowledge and input on showers, as you clearly know a lot about it. I'd respect your comments a lot more if they were a bit more polite. You don't have to back off on your beliefs at all to state them firmly and with respect to others. Thanks.
  4. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,173
    Location:
    North Vancouver, BC
    post(s) deleted by John Whipple
    Last edited: Mar 17, 2014
  5. mtcummins

    mtcummins In the Trades

    Messages:
    380
    Location:
    Pittsburgh PA
    Ha, this extreme idea of safety reminds me of the discussion on putting GFCIs on refrigerators. Why is it that specific trade people think that every little minute detail of their trade is a life or death issue? Is this just protectionism? Fear of the DIYers taking their work away? Can we really not be reasonable in our discussions about what is truly important vs what isn't? I have a news flash, if this is how you view your work... not everything you do is all that important in the grand scheme of things. I doubt many plumbers in here would have an actual problem with a tiler setting a kerdi drain, if they're experienced with PVC/ABS connections. Maybe some will say otherwise, as it is prudent to protect their businesses. But really, its not rocket science to make one connection, and its a connection that under 99% of circumstances could be made with a shoestring (no cement) and not leak. With the exception of course being when you plug up the drain and go bobbing for apples in your shower stall. That said, if you just asked why concrete has anything to do with plumbing... put the kerdi drain down and go call a plumber... right now.

    I get that you're doing things by your prescribed code. I also get that there are probably less than 100 bathroom remodels in Pittsburgh that cost $20,000. Prolly hard to believe in Vancouver, but here you can buy a decent house for about double your high end bathroom remodel number. And that's in a decent neighborhood. Most people quite simply do not spend this kind of money on remodels here.

    That said, if you can find someone willing to waterproof anything, you're doing well. Try to sell them on this, and you better have thick skin. Most of the stuff I take out isn't waterproofed at all, if I'm lucky its tile on cmu, often its tile on gyp board that's rotted all to hell, moldy, etc. I waterproof b/c I think its important to do so, even when I could get away with just doing cmu and tile in a tub surround. I don't flood test b/c I don't think its necessary with membranes, as if you know how to install them and are careful around them, you know if its going to leak or not. I would flood test a liquid system, if I chose to use one.

    I won't share my company info, but I'm not looking for any work, so no worries to any of you out there looking to build indoor goldfish ponds. I won't risk your whole family's lives by building a shower in your home. I have a set of regular clients I work for on occasion, and I do work for my own property. I'll be the one who has to fix all my showers that are in imminent danger of leaking any second now.

    The shower stalls I install for most of my clients are not tiled. They're not that type of clients. Those showers tend to be Vikrell units of 1-4 pieces, and don't require most of this work, just good straight stud walls, sturdy level floors, and proper assembly of parts. I sometimes, though not too often, build a shower in one of my own properties, and the kerdi system works great for this. Most of these installs are still tubs with a tile surround though, so there's no pan to flood test.

    I'm not sure how respect and proper shower construction are mutually exclusive. If you want to make a dent in people's perceptions (that are definitely more often than not led astray by HD types, I agree), you won't do half as good a job with a sledgehammer over people's heads (they tend to resent that a bit, it turns out, and the information just leaks right on out of their smashed in skulls (perhaps they needed flood tests on their brain-leak waterpoofing before sledgehammering?)) as you will with polite instruction. Its that hole attracting bees with honey thing...
  6. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,173
    Location:
    North Vancouver, BC
    post(s) deleted by John Whipple
    Last edited: Mar 17, 2014
  7. mtcummins

    mtcummins In the Trades

    Messages:
    380
    Location:
    Pittsburgh PA
    Wow, some lucky company saw a sucker coming to get you to pay that for kerdi products. I pay nowhere near that. I'd be a kerdi hater at that pricing too. And I don't do mud beds with kerdi, they're unnecessary. So all of your pricing info is way off the reality I live in.

    But, thats pretty much beside the point... if you actually read my post, I said I don't install these for clients. I install these for my own projects/properties, and I spend the extra money to waterproof it right b/c I feel its the right thing to do. I actually spent more than your number on my most recent kerdi shower (in my master bath), which was larger and had niches, a bench, etc, so it took a good bit of product to seal it up right.

    "I bet most clients are never informed and are blind to the fact that their new shower is leaking from day one." Wow, this is a bold statement based on nothing. Once again, a moot point b/c I don't put these in clients homes, or at least haven't to date. But assuming I did, you're still making an awful lot of assumptions to make a ridiculous claim like this.

    Build your showers your way. I'm sure they're done well and that's fine. I have no interest in "converting" you to kerdi, or telling anyone else out there that likes hydroban or noble or whatever they like that kerdi is better than what they use. For those people who want to do their own shower installs (which is what this forum is mostly about), Kerdi is a great product and does its job well. If you're halfway decent with thinset, you can make an extremely well made shower w/o some of the hassles that those of you who are pros at this do (such as creating a mud bed). If you don't like it, don't use it. But don't come on here telling people that its junk when you don't even explain how to properly build a shower using kerdi's system... you've just used kerdi in place of your waterproofing methods and ignored the rest of the system. Then you make claims about improper installations and such and such.

    For those of you looking at Kerdi, don't let JW scare you away with this crap. I agree with him on some things, do your homework, research the different options. Choose one of his methods if you're comfortable with that. Install them to manufacturers specs for your peace of mind, and know that whether you choose Kerdi or Noble, or most of the liquid systems, you'll have a great shower if you install them correctly. Do the flood test if it makes you happy - I'm not opposed to it, just find it unnecessary if you know how to properly install a membrane shower system.

    I'm done with this conversation, its clear that its going nowhere. Say what you will, I've said my piece and I'm not responding anymore.
  8. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,173
    Location:
    North Vancouver, BC
    post(s) deleted by John Whipple
    Last edited: Mar 17, 2014
  9. pitterpat

    pitterpat HandyWOMAN

    Messages:
    46
    Location:
    Indianapolis
    I think that John you need to go to a Schluter training session to understand their products, especially Kerdi. And go to the CTEF to see the water chest made with a cardboard box with Kerdi lining which has been going strong for about 6 years as an ice chest. Thickness of the Kerdi has nothing to do with it's waterproofing capabilities.
  10. J Whipple has good points. He makes it clear when he hammers his point home.

    Over the last year I have seen John Whipple's posts honing in on several weaknesses in both Kerdi AND in the JB forum's systemic bias preventing the alternatives to Kerdi from being considered as reasonable. John Whipple is articulate.

    All they do at the JB forum is to raise doubt about the alternatives to Kerdi. I find Jim Jadnashua to be a repeater for the same talk; no matter how much he may be all nice and well-intentioned, he is doing harm by defending Kerdi in multiple posts and not building one Redgard shower. not looking at the fact that there are millions of showers built with good product. The internet has places where people say the orange one is "so" good, and jadnashua is a repeater.

    I saw a box made of Hardiboard. It was sealed with a glass top. It held water. The people demonstrating Hardiboard used this box to sell the idea that the Hardiboard could be used for shower walls. That was about 10 years ago. Since then I've learned not to be impressed by the water box trick. About 7 years ago in fact at the JB site, senior people wrote that the water box trick (for Hardiboard) was a sham trick. It doesn't prove watertightness, apparently, because the wicking and pressure are different when built in, not a box you carry around from one demonstration class to another.

    The Hardi people never said one had to seal Hardiboard. So they implied their product was good enough for shower walls, without any membrane. Back in those days one could staple a sheet of poly to it, on the outside side. But staples = leaks. But between you and me, we all know that walls are not critical areas; floors are. But why build a box and show that water didn't evaporate through Hardibacker? Why? What they accomplished, after the initial GOOD impression, was to make me doubt them since they were implying it was waterproof. Schluter is similar: they engage in indirect marketing by hiring the JB forum to spread misinformation and fear about all their competitors' products. Bad boys. Jim Jadnashua, give this some thought. John Whipple has made good points.


    Hope this helps.
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    I have used Redgard, I think a sheet membrane is more reliable - it's easier to get full coverage without lumps or drips or pinholes. I used it this week because it was the best for the job at hand, but I didn't particularly like it. Lots of people get instruction and build showers other than with Kerdi at the John Bridge site...they have info in their library on how to do it and will guide you, if you ask. One person's experience is one peron's opinion, just like mine and John W's. Each has their own opinion based on experience and training. A shower made with Kerdi is by no means the only way to build one...lots of other methods work and work well. They each have their advantages and disadvantages, but all can perform well. It depends on your expectations. ANY sheet membrane IMHO, is better than a traditional liner system as there's so much less to get wet. Reducing moisture will reduce the chances of mold. Mold requires three things: the spores (everywhere), moisture (you can control), and food (easy to leave behind unless you have perfect maintenance and cleanliness - unlikely). The surface applied membrane methods (and Kerdi is only one of them) limit how much can get wet, which means it dries out quicker, which limits the likelyness of mold. BTW, I have been trained on Kerdi.

    The big thing with cbu is that they are all stable when wetted...and, they expand and contract similarly to tile, so they make a good substrate in a tiled environment, whether it gets wet or not. Some are more impervious than others, and some wick water more than others, but their primary purpose is to hold the tile well, and that's a function of their stability and expansion and contraction properties that match tile's.

    I think in all of the discussions that I've tried to bring out facts and dispell misconceptions. I suggest Kerdi, but also have suggested Wedi and other systems in order to get people to think other than a traditional shower. This is all part of being an informed consumer, but it's natural to recommend products you have used and are comfortable with. John has more experience and prefers different products, but doesn't understand Kerdi and therefore seems to downplay it's effectiveness. With ANY product, if you don't install it properly, you'll have problems. There's a lot of resiliency and flexibility with the Kerdi system as well as others. Choose your preference on your comfort level, local availability, support, and needs, but don't say the product doesn't work when you don't have a clue. Craftsmanship is key in whatever method you use...do it well, do it once, be happy.
  12. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,173
    Location:
    North Vancouver, BC
    post(s) deleted by John Whipple
    Last edited: Mar 17, 2014
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    I wasn't building a shower where I used Redgard, I was repairing some subflooring where I used it for its antifracture capabilities over a seam I had to make and to provide a little protection around the tub ends. Other stuff may have been better, but it was specified for that application and it was free, the tile dealer gave us enough to do the job. I was helping my sister. I would have preferred tearing the whole thing out, but that was not in the budget. The tub was installed sloped to the room slightly, and there was damage on each end that was repaired. It was a patch that should last long enough to get them to the point where they can afford to remodel and do the whole thing right.
Similar Threads: Installing cement
Forum Title Date
Shower & bathtub Forum & Blog Installing Cementboard New Tub Nov 14, 2012
Shower & bathtub Forum & Blog Installing Glass Tile over Dimensional Lumber Sep 10, 2014
Shower & bathtub Forum & Blog Installing a handheld shower with Ell (Newbie) Jul 31, 2014
Shower & bathtub Forum & Blog Installing NobleSeal CIS over Green-Stone Ethical Concrete Jul 8, 2014
Shower & bathtub Forum & Blog Installing a Kohler Acrylic Windward® tub, K-1113 60" x 42" Jun 15, 2014

Share This Page