Water Where It Shouldn't Be

Discussion in 'Shower & Bathtub Forum & Blog' started by daavewaard, Jul 17, 2014.

  1. daavewaard

    daavewaard Member

    Messages:
    45
    Location:
    California
    I have read recently that home builders installing exterior siding are often adding a drain plane behind the siding so that when water gets behind the siding it has both a way to dry out and exit.

    Consider that water situation compared to the common shower and the shower pan. Please help me understand that when I install that gray heavyweight rubberish barrier (available at Home Depot) under the shower pan or tile bed, and I carefully fold it and extend it's sides up the wall quite a bit, it is meant to catch any water that might get past the shower pan or through the grout, yet there is nowhere for the water to drain from there. Am I correct in assuming that while the rubber barrier protects the house framing, it creates a nice place for water to accumulate and perhaps nuture ever more bad elements? Am I correct in assuming that when the rubber barrier is full of water it will then overflow onto that valuable framing?

    Is there any new method being used for showers, or is there anything better on the horizon? Thanks!!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,183
    Location:
    New England
    The liner in a conventional clamping drain shower by code (not always enforced, unfortunately!) is supposed to be on a presloped mudbed. THen, the liner is sealed to a clamping drain, and the drain (if it is installed properly, again, doesn't always happen), will have weep holes to allow any of that accumulated water to drain out. So, there IS a path for the moisture to drain, but it won't work if the liner is not sloped, or has birdbaths, or the drain's weepholes get plugged - all common mistakes.

    While not new, there are 3-4 companies that make surface applied membranes (the tile is installed directly on top of the waterproof membrane) with a special drain. Using one of these systems, you do not have the cement based walls or pan that can absorb moisture, so the entire shower dries out much faster. Schluter, Laticrete, Noble, and others make membranes that are designed to be installed that way. My preference is Schluter, but any of them, properly installed, will work great. The company that has the biggest library of videos showing the technique is at www.Schluter.com lots of YouTube videos showing how one goes together. Noble has one that I've found on their website (it's old, and they have a bunch of new things like drains, etc. not shown in that video), but it does show the differences, but not the details of theirs verses Schluter's. Laticrete's system is very similar to Schluter's, but is new this year. Both Noble and Schluter have been selling their stuff since the 1980's, so there's a much longer track record. One of the posters here has a grudge against Schluter, so take that into consideration when he responds. ANy of them can make a superior shower verses a conventional construction, but any of them, done right, should be problem free until you decide to tear it out to remodel again. Unfortunately, one big industry association says that 70-80% of the tiled showers are NOT installed properly, so they get a bad reputation. It's not hard, but it is very detail oriented...all of the details must be done right to work.
  3. daavewaard

    daavewaard Member

    Messages:
    45
    Location:
    California
    Thanks for the reply. Very helpful information. I was not aware of the weep hole feature in those drains. It is clear that the slope toward the weep holes is critical.

    I will definitely look at the sites/products you recommended.
  4. johnfrwhipple

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

    Messages:
    4,550
    Location:
    North Vancouver, BC
    I like my use of drain mat to replace candle wick....

    That's new.

    JW Style
  5. daavewaard

    daavewaard Member

    Messages:
    45
    Location:
    California
    May I call you Mr. Style? I apologize for not following this part of your post: "I like my use of drain mat to replace candle wick...." Perhaps you might include a link. Thanks.
    Last edited: Jul 17, 2014
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,183
    Location:
    New England
    If you choose to go with a conventional clamping drain, the traditional method of keeping them clear is to use pea gravel, chunks of tile, etc. There are some engineered solutions to keep the weep holes clear - Noble makes some as do some other companies in the form of a wicking mat. As I said, I think that a surface membrane built shower is a vast improvement over one using a conventional clamping drain (which does work, if you build it properly); primarily because, properly done, a surface membrane prevents ANY moisture from getting into the structure and beneath it's layer. The drains used with a surface membrane, at least most of them, do not have nor need weep holes, since there's just the thinset and tile on top of the membrane so there's no volume that can accumulate moisture (if the slope is proper). Prior to any moisture accumulating, since there's very little that can get there, it tends to dry out towards the top. That doesn't happen with an inch of porous deck mud beneath the tile when building a conventional shower with a liner. A conventional shower, using either mudded walls or the more typical cbu, is not waterproof, but is not harmed by moisture. The liner keeps moisture from percolating down beneath things, and rotting out the floor and walls from the pan. The vertical surfaces tend to shed the vast majority of water, and a vapor barrier behind it prevents any from getting into the walls. If the pan is not built properly, moisture can wick up the walls, though, and make a mess, as the pan can allow moisture to pool (this is why the preslope is so important).

    Keep in mind that neither tile nor grout is considered a waterproofing layer...it is a decorative, wear surface. A properly built shower should not be damaged by moisture even prior to installing the tile.
  7. johnfrwhipple

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

    Messages:
    4,550
    Location:
    North Vancouver, BC
    You need to talk with an old plumber to understand what Candle Wick is.

    Then look at some of the drain mats and imagine you cut strips down - say 1" wide and then ran those to the drain.
  8. johnfrwhipple

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

    Messages:
    4,550
    Location:
    North Vancouver, BC
    I did an image search for you today looking for pictures showing the candle wick and there appears to be none online.

    Terry or HJ might have some hidden deep in their vaults of info....
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,183
    Location:
    New England
    Candle wick (i.e., cotton string for the most part) can be used to create a channel to the weepholes. There are at least several companies that make various engineered versions of them. Here is one, not saying it is by any means the best, and certainly isn't the only one.

    Attached Files:

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