Foam Niches

Discussion in 'Shower & Bathtub Forum & Blog' started by johnfrwhipple, Apr 13, 2013.

  1. johnfrwhipple

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

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    Waterproofing Your Kerdi Board Niche - Using Ardex 8+9 and Kerdi Corners

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  2. johnfrwhipple

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

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    Using SK Mesh from Ardex with your Kerdi System

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  3. johnfrwhipple

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

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    A helping hand for a Kerdi Installation

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  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    I'm sure John's technique works, but why not talk directly to the people that make it, warrantee it, train it, and have over 20-years of using it and testing it over and over again. It's one thing when you may have lots of other contractors on the worksite and you can't control every aspect of who does what to whatever, but it's a different thing with a DIY'er. The Kerdi system works as presented by the manufacturer, has been tested by independent agencies, and has 100's of thousands of installations in the USA and more in Europe. If it was a product that required all of these extra steps John performs to produce a reliable result (implying that it didn't work 'out of the box'), they'd have long since been out of business, but have been around for decades. Any time somebody builds something, there's a chance they either do not know what they're doing, or don't believe the instructions and do something else. As a result, there will be failures, but they are not the result of the system, they are in someone's interpretation of the instructions, or their total disregard for them, or an accident that occurred that they didn't rectify. Some redundancy is reasonable, but testing has shown a properly installed seam in Kerdi only wicks about 1/4" under standing water (only happens during a flood test), having a minimum of 2" overlap provides LOTS of redundancy in application errors for real world finished assemblies!

    John's dislike for Kerdiboard and his 'sample' of a test when he stripped the orange covering off and used it to build a water box is just one example of him not understanding the product. That covering is for topical strength to the board and thinset compatibility...it is, and always has been that the closed cell foam is the waterproofing. In a typical installation, you use Kerdiband or Kerdifix on the edges, which seals the edge, and there should be minimal wicking beneath it, if any. Plus, it is not designed for use as a floor in a shower, and only for walls where it is unlikely to see any water pressure, especially after it is covered with tile. All of the Schluter foam shower trays either come with Kerdi fabric membrane on them (some of those designed for linear drains come that way), or are designed for it to be applied during installation.

    The proper use of the proper materials, and understanding their use is critical. Choosing to make an installation more bulletproof is sort of like adding bulletproof glass on top of the body armor of your vehicle. Homes don't generally have bullets being fired at them, and for most people, one is enough!

    If you do two things: clean the wall (removing dust and adding some moisture so that the thinset isn't affected), mix the thinset properly per the manufacturer's instructions, and get your Kerdi membrane up on the wall before it starts to skin over, then press it in place with something like a taping knife or the smooth side of a trowel, or something similar, there's no reason to wet or clean the Kerdi membrane (unless it was unrolled and got dirty!) prior to installing it. Won't hurt, but isn't necessary.

    FWIW, the codes are written for the 'what-if' situations. A typical person may never experience the combination of unusual situations that combine to create that atypical situation, but the codes have been written and updated as experience shows a deficiency to protect the unwary from those problems. I'm sure that the codes for many things will continue to evolve as experience dictates and new products and techniques are discovered as they have evolved almost every year since they were initiated. The certification for Kerdi hasn't changed over the years, but additions have been made to make things easier and faster for the installer (such as the premade corners - the old ones worked, and still do, but resulted in more buildup).
  5. johnfrwhipple

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

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  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    How many Schluter classes have you been to to see the techniques and learn from the people that make the Schluter shower system (I've been to two, one at CTEF and one in Plattsburg, NY, Schluter's US headquarters)? As tested, the US recommended system of installation works. I'm sure the methods used elsewhere that have different plumbing codes work for them as well. As an example of the fact that things change, in the US, you used to be able to build a shower with a 1.5" drain (still can in Canada), but there were certain situations where it was found that that didn't always work, so the US code changed to a 2" drain requirement. Will a 1.5" one work? Yes, most of the time. Doing more than code minimum is fine if it makes you feel better, and is prudent in some circumstances, but for the most people it's a waste of time, money, and effort. Declaring it as essential, is misrepresenting the product. Not using the product as intended and complaining about it is also misrepresenting the product.

    I don't have an issue with your technique, I'm sure that it is a solid build, but I do take exception to your rant that it is the 'only' way to do it right. 100,000s of successful shower builds over many years says something different...the system works as designed and presented.

    Having spent over 30-years dealing with ensuring things work reliably because people's lives were at stake taught me how to evaluate the risk-benefit of different methods...there rarely is a second chance to destroy that missile coming towards you that might blow up your world, or take down that airplane that threatens your way of life - you just have to ensure you do it right the first time, and the Schluter system that is used in the USA and is warranted by them works reliably. Should you decide to enhance it, is your choice, but it is not required when you follow the instructions and use good workmanship.

    And, by the way, I have a sister living in England, and yes, over the years have visited 5-6 times, so yes, I am quite familiar with not only England, but have lived in Germany for awhile...and Korea, Jordan, and Kuwait. So, I've seen how people do things - the mindsets are different. Keep your snide remarks out of the discussion. Recognizing your way is not the only successful way happens when you have an open mind and are willing to learn.
    Last edited: Oct 3, 2013
  7. johnfrwhipple

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

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    Kerdi Board Review: IT SUCKS BAD

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  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Again with the rant and the snide characterizations...

    The reference to hundred's of thousands was for showers built, not the Kerdiboard. That's showers built in the USA with Kerdi and unmodified thinset. FWIW, others seem to like Kerdiboard, and they're in the process of building a second production line to supply demand. If it was such crap as you say, by now, people would have stopped buying it. I think it's been in the line for something like 5-years now, but would have to check to verify. Since others had a foam-core board and people were asking for it, they spent a few years trying different techniques on constructing it before they settled on the product you can see.

    If you take a Kerdiboard niche, lay it on a flat surface, and fill it with water (I don't care for how long, days, weeks), except for evaporation, it will not leak. So, set into a wall, why would you expect it to where, instead of standing water pressure, the tile got wet sometimes?

    Cadillac and Chevrolet build their cars on the same platform...that doesn't make Chevrolet a piece of crap, only less expensive. IOW, the frills you put on can easily add up, but if the guts are adequate, it can be construed as either a luxury product or a merely adequate one. Put together properly, as designed, warranted, the out-of-the-box Schluter Shower System works whether you believe it or not. Put whatever fancy design features or fixtures on top of it you wish, it's still basically a shower.

    As anyone who takes a class with Schluter, you get yourself there and home, and they pay for the training, room, and board. Nothing special, it's available to anyone who chooses to go that the regional sales manager/tech person approves. At least that's how they do it in the USA. The next time I see any cash or products for free other than what everyone gets at a class from John Bridge or Schluter will be the first time.

    As said previously, 30+ years of having to make cost/benefit decisions on things that people's lives depended on has given me a reasonable ability to look at the facts and make a viable decision on things.

    I've had enough of your comments, and unless I see something egregious, won't take the time to comment further. We all make mistakes, often because we don't understand or take the time to investigate the science behind it. You, obviously, don't understand how to use Kerdiboard, and have no faith in the NA instructions on how to build a shower with Kerdi.
  9. johnfrwhipple

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

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    Jim has left the Building !

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  10. johnfrwhipple

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

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    Kerdi Flood Test Inspection Failed because of Liquid Membrane Over Lap

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  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    What do you think makes stuff like Wedi and Kerdiboard waterproof...it's the foam. Each (and any other one out there) use a proprietary layer on it to provide thinset compatibility. As I said, you do not understand KerdiBoard.

    Schluter has (several, depending on the norms and preferences of the country/region) methods of building a shower...the use of unapproved thinsets or other topical waterproofing materials is not in the instructions. So, why bring up a shower built improperly that failed? Build it per their instructions, and it is waterproof and will be warranted by them if your workmanship is up to par. The TCNA guidelines do not show extra stuff, so technically, it is not an approved method.

    Who are you going to believe, a company that has hundreds of thousands of successful showers built according to their instructions and the certification from an internationally recognized testing agency http://www.icc-es.org/reports/pdf_files//ESR-2467.pdf that says it meets all requirements for a proper, waterproof shower; or, someone who doesn't believe them or understand their product? Here's the UPC approval for the USA and Canada http://pld.iapmo.org/file_info.asp?file_no=0004654 Both of these ONLY apply if installed per the manufacturer's instructions.
    Last edited: Oct 5, 2013
  12. johnfrwhipple

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

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    Kerdi Board Testing - A Review of Schluter's new backer board

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  13. johnfrwhipple

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

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    Kerdi Board vs Drywall: Review of water wick test

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  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Used as directed, the certifying agencies and the factory that makes and warrantees the stuff all agree that it works. Guess it's your inappropriate use verses the masses. You do not understand the stuff, and apparently never will.

    When used in a shower, the edges are either sealed with KerdiFix or banded to Kerdi. When done as instructed and designed, it works. There will be no standing water to create your horror world of improper use of the stuff.

    You can take most any product, install it improperly, or use it in a manner not designed, and have it fail. What, if anything does that prove?

    You do not understand the stuff, and probably never will. When used as designed, and installed properly, it works.
  15. johnfrwhipple

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

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    Kerdi Board Testing. What have we proved? Answers revealed...

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  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    As mentioned in another thread, if you read Schluter's Shower Manual (which the Kerdiboard data sheet references when using it for waterproofing, i.e., in a shower), and you look at the steam shower section, it only lists Kerdi and KerdiDS as suitable for steam showers...the fact it failed in a steam shower is not a fault of the product, it is a fault of the installer using the wrong materials and techniques.

    Earlier, John showed a picture of his installation of a Kerdiboard niche, he had a screw about every 4" or so around the periphery. Schluter's instructions call for screws no closer than 12" apart with one in each corner. If it was then covered up to the opening with Kerdi or Kerdiband, as designed, the whole thing would be waterproof. The instructions say, when using the optional shelf, to install the tile up to the bottom edges, then insert the shelf using thinset or KerdiFix, then finish the tiling. The tile provide additional support to ensure it stays, and they say to add some slope, if you wish, to prevent pooling, or to do it with the tile.

    A good example of not following the manufacturer's instructions.
    Last edited: Oct 20, 2013
  17. johnfrwhipple

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

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    Q: Can Kerdi Board Be Used in a Steam Shower - A: It depends on who you ask

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  18. johnfrwhipple

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

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    Kerdi Board vs Wedi Board - Which is better for a steam shower?

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  19. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    If, as I said, you read the Kerdiboard data sheet, it says for wet areas, like showers, use the Schluter Shower Systems Manual, and in the steam shower section, it only lists Kerdi and KerdiDS...Kerdiboard is mentioned in the normal shower section of that manual, but is NOT shown in the steam shower section.

    Calling Schluter Tech Support will give you permission to do some things not in the manual, like the use of a rapid set mortar if your glass tile manufacturer is adamant about it. But, the manual does not show KerdiBoard in the steam shower section at all.

    The shower you showed, was a commercial shower, so in that situation, should not have used the material. And, without careful attention to routing and placement and sealing of the steam lines and outlets, even a residential steam shower could be at risk. Cost/benefit/risk for most people, like the manual says, probably would not want to use it in a steam room. Both the steam supply line and the outlets could easily be hotter than the material's max spec, depending on how routed and installed. Cost/benefit/risk to me is too high for a steam shower.

    Just like you say you never use studs in a shower curb, but TCNA says it's fine, you have different cost/benefit/risk tolerances.
  20. johnfrwhipple

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

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    Q: How Much Does Kerdi-Board Cost - A: Lots

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