water level drop

Discussion in 'Shower & Bathtub Forum & Blog' started by johnfrwhipple, Dec 25, 2011.

  1. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    A properly built shower has NO standing water...a flood test is an absolute worst case test that a real shower should never see once completed. If it didn't leak with that, there's essentially NO water pressure to push any moisture into the seams during typical use...IOW, don't worry about it! Any water in the shower will flow down the wall and along the slope to the drain. Any (very small) amount that MIGHT get below the tile, will do the same thing. There shouldn't be ANY accumulation of moisture beneath the tile of the pan with the membrane and the slope to the drain...it MIGHT get a little damp if used continuously, but no standing water enough to wick anywhere. This is the one big advantage of a surface membrane, however achieved: the water stops at that point and doesn't saturate the substrate. Now, in a conventional shower, that substrate should handle being wet, but IMHO, it's better to never give it the chance!
     
  2. boardable

    boardable New Member

    Joined:
    Sep 27, 2012
    Location:
    San Jose, Ca
    Very true. I do agree. I am going to use bostik epoxy grout. Any good ?
     
  3. boardable

    boardable New Member

    Joined:
    Sep 27, 2012
    Location:
    San Jose, Ca
    I agree flood test is a mandatory thing. Membrane will always stay wet. Even if a little water gets there. How do you guys feel about urethane and epoxy grouts ?
     
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    While costly, and if you like the look, epoxy based grouts should be a lifetime install without regular maintenance. You can get some special effects with them (glow in black light, for example or glitter), if that's something that may go with the install design. Some are harder to install on the vertical than others (because it can slump a little), and cleanup is critical (but regular grout needs good cleanup, too) as it's harder to clean again afterwards if you miss some. Epoxy grouts have improved over the years to become easier to install and their colors will be brighter than any cement based grout.
     
  5. boardable

    boardable New Member

    Joined:
    Sep 27, 2012
    Location:
    San Jose, Ca
    I installed a euro thane or epoxy. Can't remember which it was in my parents shower. It was cleaner but yes the film was annoying took me a good 4 hours with caulking in the corners. Not sure. But with epoxy or eurothane grouts is it still necessary to caulk the corners ? Or is the grout just fine ?
     
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    Industry standards call for caulk at the changes of plane (corners, floor/wall joints, etc.). Urethane remains somewhat flexible, so you could likely use it everywhere...epoxy does not. You likely used epoxy as, in a wear surface, it's harder and stronger. Epoxy would remain easier to clean as it is a very smooth surface. Abrasion can rough up urethane.
     
  7. wilkinte

    wilkinte New Member

    Joined:
    Jan 9, 2014
    Location:
    Utah
    Hi John, I have a related question. And by the way you can view my thread at home/garden forum too, under same username.

    I flood tested my shower earlier in the week and didn't lose anything over 24 hours. As a DIYer that made me feel good. Installed the kerdi over the schluter tray.

    But, 8 hours after I drained the water, the kerdi on the floor is still damp. I would have thought it bone dry by now. Most of the thinset seams are damp looking too (dark grey). Am I over thinking this?
     
  8. wilkinte

    wilkinte New Member

    Joined:
    Jan 9, 2014
    Location:
    Utah
    John, thanks so much. My lurking here has been very enlightening and your personal response is appreciated.

    All dry now! And I used the Kerdi tray thinsetted on a level floor. The dampness in the kerdi on the floor is what bothered me. But given that I had no measurable drop in water over the 24 hours of flood test I feel good that there is no breech in the kerdi/thinse IMG-20140103-00054.jpg P1020790.jpg

    These pics are pre curb and flood test, bottom one is now, and you can see a haze over the kerdi, all dry.
    Salt Lake City-20140109-00057.jpg
    Thanks again!
     
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    A flood test is the one and only likely time you'll have standing water in a shower for anywhere near that timeframe. Yes, there may be a small amount underneath the tile if it is used lots, but the head, or pressure there is significantly lower than when you have 2-3" or more of water sitting directly on the membrane and the fact you have a layer of thinset embedded into the fleece holding the tile in place. The cement in the thinset will continue to cure for a very long time...the crystals cross-link, making not only the bond stronger, but its ability to block water better, too. A flood test can be performed at the minimum of 24-hours after install with Kerdi. Some get away with it overnight, but things do need to cure a bit. Thinset is specified after a 28-day cure, and for example, the cement deep in the Hoover dam is still warm from continued curing, many years after it was poured.
     
  10. wilkinte

    wilkinte New Member

    Joined:
    Jan 9, 2014
    Location:
    Utah
    Jim:

    This is OT, but I used to work with Sanders in the 90s, guessing that's where you were. Good times back then. I was a gov customer at the time on an EW effort and I always appreciated the pros in New England. Glad to see you got to retire, so many of us defense workers had to move on to something else.

    And John thanks for the kudos, I'll give you chances to see my stupidity when I start tiling. I just did marks around the wall. Over the 24 hours didn't see much evap (basement job).

    Tom Wilkins
     
  11. wilkinte

    wilkinte New Member

    Joined:
    Jan 9, 2014
    Location:
    Utah
    and didn't see the great tipped coin innovation until I drained it!
    Hail kerdi! or is that Heil kerdi (joking, obv)
     
  12. loudgonzo

    loudgonzo New Member

    Joined:
    Jan 7, 2014
    Location:
    Wylie, Tx
    John, thanks for your insight and 'right approach' when it comes to kerdi. We will be starting our shower build soon and we are using the kerdi kit, including the tray and curb. Are you using the 8+9 instead of thinset for the seams and would this also glue the floor membrane to the pre fabricated styrofoam floor?

    thanks
    leo
     
  13. loudgonzo

    loudgonzo New Member

    Joined:
    Jan 7, 2014
    Location:
    Wylie, Tx
    Ok, I will use some piece of extra curb and rig up something up.

    To understand your process, you are applying the 8+9 on the seams and edges only? If that's the case, then I take it you do not overlap the kerdi, and use the kerdi band to cover the seam with 8+9, as well as the edges and corners? And if that it correct, then how much time do you give after setting kerdi up to do the band, edges and corners, does the thinset have to be completely dry?

    We are in no hurry to do this job, and have no problem with waiting the appropriate time for material to set in, dry and cure.

    leo
     
  14. loudgonzo

    loudgonzo New Member

    Joined:
    Jan 7, 2014
    Location:
    Wylie, Tx
    We have not started to shop for tile or faucets yet. I'm not sure what you mean by sample board with grout before laying out plumbing fixtures, do you mean to tile and grout a few pieces to some scrap board? The purpose of this would be to get a feel for the actual process?

    I miss your second approach, are you saying to overlap the pieces of kerdi 2", and then also use the kerdi band over the seam? Wouldn't this bulge out along the seam? And is it 3 days for the kerdi thinset to cure before adding band with 89?

    leo
     
  15. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    Or, just do it the way Schluter of North America instructs, and hundreds of thousands of successful showers have been built. It seems a bit strange that adding Ardex 8+9 over an already properly installed Kerdi seam would be thinner. Done like a drywall seam, and spreading extra further away may make it LOOK smoother, but it's now just a bigger hump.

    Schluter has been selling and people installing Kerdi showers in North America for nearly several decades now...when you follow the instructions, they work, they do not leak. As with many things, you do need at least some understanding of what you are doing, and reasonable workmanship, but a little practice goes a long ways. And, if it's important to you, you don't need to wait those extra days OR spend the extra money for the extra material. Does it work, yes, is it necessary, only you can decide, but the manufacturer doesn't seem to think so, and will offer you a warranty done to their instructions.
     
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    FWIW, a properly built Kerdi seam with unmodified thinset, while it may wick a bit after the first day during a flood test, still does not leak water out of the pan AND, as is true with all cement based products, they continue to cure for many days, with them being specified at 28-days. In the process, the seam gets stronger as the cement grows its crystalline structure and become even more waterproof which will limit wicking and still never leak. This was shown in one thread here where you raised big red flags...in that instance, at least one of the seams wasn't to spec (not enough overlap), but even then, it did not leak any measurable water as the level stayed the same and no water was seen anywhere else in the structure. The same test, done later after things cured a bit and the one seam was redone to Schluter's minimum 2" overlap, then neither leaked nor wicked. How waterproof does a shower have to be? And to Kerdi verses Kerdi DS, unless vapor pressure is an issue (like in a commercial steam shower), how is thicker better, just like how is 1/2" glass more waterproof as a shower door than 1/4"? At least with the Kerdi, it has tile on top of it to protect it. The 1/2" glass is stronger, but it is NOT more waterproof, which is also true of the varieties of Kerdi (vapor pressure isn't a big issue except in a steam shower). They're both pretty tough. If you can't control the use of the space until it is covered with tile...fine, DS may offer a little more protection, but it is NOT more waterproof.

    The worst situation is during the flood test. There is NEVER standing water on those seams ever again once they are tiled if the slope is built properly. As a result, even if it does wick a bit during the flood test, if it doesn't leak out, once things are actually finished and in use, it will not leak. Schluter has a vested interest in showers built with their materials to not have problems....after something like 20-years in the USA and Canada with Kerdi products, and hundreds or thousands of showers built this way, if they did not work, they'd be out of business.

    I do not know the building codes outside of the USA (Canada's are similar but have their differences), but I firmly believe, if the Schluter Kerdi Shower Systems Handbook didn't produce a product that worked, they'd either have changed it or be out of business by now. That things are done in a different manner elsewhere is of little concern when I've seen it work, and dozens and dozens of other pros I know have had no problems, and hundreds and hundreds of DIY'er people on www.johnbridge.com have done the same with their one-off showers. It would seem that the learning curve to get a reliable result isn't all that hard with a little study and some helpful backup (rather than claims that it won't work). Certainly, a DIY'er will make some mistakes, but there's enough overlap with a seam where it still doesn't actually leak out. More just for the sake of more is wasteful.
     
  17. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    Both thinset, grout, and tile are somewhat porous, but once Kerdi is covered with thinset and tile, how much water pressure is there on it? Considering that probably 99.99% is covered by mortar, and no more than the tile thickness, how much head does the water have pressing down on the membrane? A VERY small fraction of what it had when it was flood tested. It's not like if you had a steady spray on the grouted tile, you could get a stream of water going through...we're talking barely enough to wick down there, if it ever does in between drying and shower users. There's a big difference between having a inch or so of deck mud underneath the tile and a waterproof membrane on top of it. If it did not leak during the flood test, it is NOT going to leak once covered with thinset and tile and, it has all the time it needs to cure. There's intentionally a lot more 'room' for moisture in a conventional pan of deckmud, and needs a drain with weep holes. As a result, there's more water pressure because there's room for moisture and it's 8-10x thicker (thus head, or water pressure). Thinset is MUCH denser, and MUCH thinner...apples and oranges.

    I don't care how much water gets dumped on it and runs down the drain...it's like the saying...water under the bridge. On a wall, any that might get to the membrane flows on its own or, since it can't penetrate the membrane, the drying on top will draw it outwards. On the pan, unless your slope is improper, it flows (slowly) or evaporates, but there's literally no head or pressure - the tile and thinset are shielding it from the spray, and anything that may (and not much will) gets below, still is shielded by the materials above it.

    FWIW, not everyone reads, let alone understands the instructions on how to do things. For that reason, without knowing the specific circumstances, any product, misused can have problems. Your example doesn't mean much.
     
    Last edited: Jan 16, 2014
  18. eurob

    eurob master tile and stone installer

    Joined:
    Feb 16, 2013
    Occupation:
    master tile and stone installer
    Location:
    Montreal
    I think you are mistaken the width of the curb - large as you call it - with practical when cleaning the shower floor or even use it as a step. Other than aesthetically a narrow vs. large curb doesn't serve any purpose.

    No curb or curb less is a different story .
     
  19. eurob

    eurob master tile and stone installer

    Joined:
    Feb 16, 2013
    Occupation:
    master tile and stone installer
    Location:
    Montreal
    Besides the possibility of cutting the curb , massiveness could be resolved . And there is no water pressure , head pressure -- other than the one added by singular thinking -- or any other pressure you see with using it.

    Oh , I got it...... A chance you didn't see the Eiffel curbes I am building... LOL
     
    Last edited: Jan 17, 2014
  20. loudgonzo

    loudgonzo New Member

    Joined:
    Jan 7, 2014
    Location:
    Wylie, Tx
     
Similar Threads: water level
Forum Title Date
Shower & Bathtub Forum & Blog New tub level, but doesnt drain water all the way Nov 14, 2016
Shower & Bathtub Forum & Blog 2nd floor shower drain water level? Mar 28, 2010
Shower & Bathtub Forum & Blog Cold, hot water lines to new bathroom Wednesday at 5:54 PM
Shower & Bathtub Forum & Blog Cutting into block wall for shower water supply Tuesday at 6:47 AM
Shower & Bathtub Forum & Blog Faucet wall tubes and wall tube escutcheon is not water tight Feb 9, 2017

Share This Page