Houzz Logo Print
johnfrwhipple

What is the difference in shower waterproofing liners?

By Any Design Ltd.
8年前
最終更新:8年前

Last night I received an email from California asking me the difference in shower liners. Specifically the difference between NobleSeal CIS and a rubber membrane or hot mop. This lady is in California and is starting the steps of doing over her curbless shower because the first one failed.

Understanding the difference between the two systems is key to avoiding failures like she had. So, what is the difference between different type of shower liners? Lets look at that and why I think NobelSeal CIS should be used for most curb-less showers.

Waterproofing showers is a challenging job with so many options. You can make custom metal pans, Use a hot mop, Use a rubber liner, a pvc liner, you can use liquid waterproofing, cementious waterproofing or one of the dozen choices in topical sheet membranes.

My favourite topical sheet membrane of late is Laticrete's Hydro Ban Sheet Membrane (put not for the shower floor). I have been using lots of it to build my steam room projects but it is not my first choice for the shower floors in my barrier free showers since it is not designed to be used with a traditional clamping style drain. To tie into a clamping drain you need a liner that is between 30 and 40 mils thick. Your bank card or Visa card is 30 mils thick. A mil is a thousandth of an inch so it is 30/1000" or 40/1000". Now if you use one of Laticrete's drains you can use their membrane but my preference for barrier free shower builds is the ACO linear shower drain.

This particular job in California was one that an ACO linear drain was used with the ACO clamping drain.


Capillary Breaks for Barrier Free Shower Designs · 詳細


An approved shower liner was used and a recess in the subfloor was made to alllow for the barrier free design. The problem was the shower liner used on the job was one designed for a regular shower - one that has a curb or shower dam. California hot mops and rubber or PVC liners do not in my opinion allow for a curbless shower build. The big reason why or main difference I see is the amount of concrete that needs to be added over top of them prior to installing the tile.

Lets say you use a black rubber membrane or Hot Mop. You need to install something like a 4-1 mix at the very least 1 1/4" over top. ideally more in the 1 1/2" - 2" level. If you want a premium mortar bed then Laticrete's 3701 is ideal and what I use, but this requires a 2" height and 2"x2" galvanized mesh reinforcing. Now if you prepare your floors for tile you can bond Noble Company's NobleSeal CIS or TS right to the floor. Then tile right on top. No 1 1/4" - 2" built up over top. This is the key to understanding the differences in the membranes.

Something like NobleSeal CIS, Kerdi, Hydro Ban Sheet Membrane, DalSeal TS and on and on is the way the product is made. The sheets all have a fury mesh or fleece attached to them that allows thin-set to stick to it. This means you can bond your membrane the floor and then tile straight away. I also find I can bond a stainless tile edging like Schluter's to this membrane and in affect make a little capillary break in the shower floor.

So what can go wrong if you decide that the process I follow is excessive and that regular shower liner is fine. Have a look at these pictures. I am reposting them (with permission) in hopes of helping other people understand this key design step.

コメント (10)

  • PRO
    Mint tile Minneapolis
    8年前
    最終更新:8年前

    I Feel for this poor lady, someone has sold her on their ability to build a difficult curbless shower.

    They clearly do not know what they are doing and likely this homeowner wouldnt know what to be looking for and how would they.......now there is a staggering amount of money being lost here....

    John, can you share how and where this lady found and hired these hacks and how much $$ will be displaced in the end?

  • PRO
    By Any Design Ltd.
    質問の投稿者
    8年前

    Hey Erik (Tundra). I believe the crew came highly recommended and this lady did her research and checked references. It is an unfortunate scenario. I see this style of install all the time lately and it is so wrong that the work can be done. Checked by city inspectors and passed.


    I do not think we will see any change to local codes any time soon and I'm sure more failed installs like this are going to be a common post on forums like this.


    The TTMAC and TCNA have no clear specifications for barrier free showers like they do in Australia. Maybe in ten years things will be different. Who knows.


    I'm going to assist in the rebuild and do my best to help her find installers in California familiar with topical membrane (bonded) installs. I have quit a few client now in California that have found installers and I have suggested they find them via the local sales channels. Typically I recommend they track down the stores that sell products like Kerdi, NobleSeal TS, DalSeal TS and Laticrete Hydro Ban sheet membrane. Then call those same company and ask for the local sales rep. Once they get a list from each source typically there is only one or two people that are doing or working with these materials.


    My client in New York has chatted with me on about three design calls now and we have discussed many options, Then when these options are pitched to the builder they have trouble finding the products. Or the store selling them recommend other simpler methods which may or may not work.


    I'm not sure what a good answer is to this problem. As a client I think this lady did everything right. How can an average person outside the bathroom building business gain experience that takes years to achieve?

  • PRO
    Mint tile Minneapolis
    8年前


    J.W. said: " How can an
    average person outside the bathroom building business gain experience
    that takes years to achieve?"

    HGTV and the like are trying to bridge that gap in a nutshell !!!

    Perhaps this client was wrongly appointed to this crew/installer. Highly recommended tile crew "does not mean" a track record of successful curbless or linear drain shower builds. Dare I say some fault may fall on a poor inspection? At least she now has you as a guiding light ..

  • texasgal47
    8年前

    John W., thank you for this post. You read my mind as I was wondering how to go about locating someone who is experienced in a specific install issue. I'm seriously considering a large window install in a shower. One of the consultants on the GW Windows forum reports no problem taking care of his end of it. However, I had no idea how to locate a competent tile installer who will provide a waterproof membrane. I'm in a large city and will use your recommendation for locating the right person if I proceed with this project.

  • PRO
    By Any Design Ltd.
    質問の投稿者
    8年前
    最終更新:8年前

    I had a nice chat with my client in California the other day trying to further describe the difference between a rubber membrane and a membrane like NobleSeal CIS. The largest difference is that NobleSeal CIS can be installed with thin-set over a tin ready substrate and then tile installed directly over it without the use of a mortar bed over a traditional rubber liner.

    The shower above is being ripped out and from studying the pictures I can see that the drain connection at the primary drain did not leak and only the water weeped out the edges and over the flap. With a little more proving we found that there was no pre-slope and not enough drop.

    So much for an experienced installer.

    And remember everyone - this shower was inspected and signed off on by the local California inspector. The shower did pass a flood test.



    The shower was supposed to be designed with a 1.5" drop down in the framing. Clearly this was not the case and from this demolition photo you can see how the water escaped by travelling out the left and by climbing up the edge of the wood. This staining showing how water can travel in so many locations and directions.


    What's worse is that the back wall there is also a pocket door and that by itself is not a tile ready substrate. We will need to investigate further looking for structure damage. I hope we find none.



    This photo shows that there was no pre-slope used under the liner. You can see some care was taken to get the lower flange of the ACO clamping drain tight or flush with the subfloor. But the photo shows as well this connection did not leak or we would see evidence of staining on the subfloor. Sadly the wall tile is going to need to come out next to replace the waterproofing liner.


    With such little drop in the framing I think the entire shower and perhaps the drain choice might need to be revisited. What a gong show.



  • PRO
    By Any Design Ltd.
    質問の投稿者
    8年前
    最終更新:8年前

    In this shower build of mine you can see the shower under flood test. The water level brought right up to the edge of the dry side. You can see how I used some Ardex 8+9 (brown stuff) to keep the water from wicking out of the shower while the flood test was set. This drop after pre-slope was around 1.5". A little light of the 2" Laticrete likes to see but the mortar bed was later bonded to the NobleSeal CIS which was bonded to the pre-slope. Nothing in this build is floating.

    later the capillary break was added on the dryside with another back up at the entry and I used my Ditra Drain weep system under the Laticrete 3701.

    Same shower designs. Same drains. Same primary drains. The differences - the height of the drop for the rough work and the type of waterproofing membrane used.



    Like the failed California shower this job also passed local inspections. Had a dry layed rubber membrane and no though to containing the water.


    I did not like it. I pulled art the seams and found the work sub par. So I ripped it out. And did it over. But I did this at the start of the job. before any other work was done. Not after the job was finished and payed for!


  • PRO
    Mint tile Minneapolis
    8年前
    最終更新:8年前

    Another "Thinbed Bonded" example shown here with A modified proline quickdrain install under flood test.

    The blue membrane on the shower floor is Bonded to the mortar bed beneath with a quality modified thinset and is the actual Tileable surface.

    ( I.E. The blue membrane is what the shower floor tile will be set into with more Modified thinset.....)

    I must say, I have learned a LOT from John on improving my methods and material choices while installing these linear drains and curbless shower builds....

    On a side note it is sickening as A tile shower builder to see this poor homeowner go thru this . If this was my install and I had to tear it out and re-purchase all materials and re-build id be immediately out of business when done. And yes I would do it in a heartbeat no matter the cost. ( built twice, materials purchased twice, demo done twice, landfill twice etc.)

    Im guessing after the redux this project will price in the 15-20K for the shower alone.

    The biggest dissapointment is likely the homeowner will eat this cost defecit and likely these novice shower builders are at someone else's home as I type.

    No accountability.

  • PRO
    Srw Contracting Inc
    8年前
    Is there a need for a capillary break when the entire floor is waterproofed? In a curb less entry I always flashed up wall 4" outside the shower with the noble or Kerdi band

    Doesn't sound like the original post pictures was all From capillary water movement
  • PRO
    By Any Design Ltd.
    質問の投稿者
    8年前

    I think most of the leak was from water travelling sideways. Lets call it lateral movement. Poor seaming. No outside dam corners. No pre-slope.


    The design: Use the old school liner and drop the plywood an inch clearly does not net a well performing shower.

PR