Greetings –
In a past life I made my living as a tile setter. This was many moons ago and I recognize that there have been many new marvelous materials introduced since then. So …..
Given that the technique of the day, in that day, for a leak-proof shower pan was a very heavy mil vinyl or plastic sheet (trade name ‘SealsIt’ of there ’bouts comes to mind), what is the prefered method of creating a sound, absolutely waterproof membrane in a walk-in shower?
I mention walk-in since the shower isn’t your standard rectangular space with a curb at the door. There is no curb at the shower proper, it’s located around the corner at the entrance, so-to-speak, of the drying/dressing area. Thus it would be impossible to fold sheet goods the way we used to fold the inside corners of the membrane. There are two outside corners in this arrangement.
I’ve researched several fluid applied membranes and just wanted to get some feedback from anyone that may have used this or that product. Ease of use; fabric reinforcement issues; bridging cababilities/substrate requirements.
With regard to the latter, the bathroom and shower have PEX heating tubes under the finished floor. In the shower, the PEX will be covered with a minimal lift of drypack or grout on which the membrane will be placed. Thus if fluid applied is selected, it will have to adhere to less than optimally cured cementious material (can’t wait forever to finish this bathroom).
How durable are these fluid applied membranes with respect to working on them once installed? We always placed a thin lift of mortar or drypack over the sheet membranes to protect them after testing so’s to be able to avoid damaging them during the tile installation itself.
The entire shower and drying/dressing area will be mud-set ceramic or granite tile so there will be a lot of activity in the area after the membrane is installed.
Thanks for any up-to-date info on the question of shower membranes.
Replies
Quite a post.
There are currently two types of approved shower pan materials, and a few others can be approved or are equivalent, if proper measures of installation are taken.
The two are........... drum roll........... (1) Sheet membranes like PVC and CPE applied UNDER the setting bed; and (2) The old fashioned hot mops. Here in California, we still use hot mops, 'cause they are so cheap, and very serviceable. For my own home, I used PVC.
The other materials can be a product called KERDI, made in Germany by Schulter (pronounced Shloooter) which is applied OVER the setting bed, directly under the tile. The Kerdi system, which is not Code in our area, but can be approved with some arm twisting, is neat. The fabric is glued to a special proprietory drain, and might be just perfect for handcap shower or a curbless shower which you have described.
Other pan materials can include the liquid types like Laticrete 9235 but their weak point is the drain connection, because it connects to a standard two part shower clamping drain, and because it is a liquid latex, there is not much to clamp to. Other materials include lead and copper, which are falling out of style and can not be pitched to the required quarter inch per foot.
You asked specifically about the liquid membranes. They are expensive (about $60 a gallon) and messy to use. They are applied with a roller or brush onto any substrate, including masonry or EGP plywood, then a fiberglass mat is pressed into the mess, and rolled into place, then a second coat of the latex is applied. The stuff is excellent but very, very messy. Wear protective gloves, hats, glasses, etc. You will need to throw away your clothes after the job. The stuff is really sticky.
They are great for normal floors and shower walls. I would never use them for the primary membrane for a shower, because there is simply no good way to interface them with the 2 part drain. In a curbless or handicap shower like you have described, the whole room is turned into the shower.
My advice to you, if you are building this from ground up, is to over size the floor joists by several inches. Then chop away at them so material is taken out to make a slope of a quarter inch per foot toward the drain and account for a mortar bed of an inch and a quarter. This has to be done on the whole floor, e.g., turn the whole room into one giant shower. If you do the framing this way, the elevations at the transition to the adjoining room is perfect for wheelchairs. Apply a plywood subfloor. I like inch and an eigth T&G, which is really really stiff.
But it sounds like the floor is level, so you would have to add a pitch to it on top of the radiant heating. A full sloped mud bed would again be my first choice, but you may have elevation issued with the adjoining room. I can suggest workarounds on this if you would like.
In any event, I'd install a Kerdi Drain which is PVC, but if supported well, it is fine.
AFter you have applied the setting bed (mortar or whatever) apply the Kerdi membrane to the setting bed, glue it to the Kerdi drain, and set the tile with regular thinset on top of the Kerdi membrane.
This is what I spec for handicap showers, Dennis.
Good Luck.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Edited 5/22/2003 12:11:43 PM ET by Boris Yeltsin
Edited 5/22/2003 12:28:28 PM ET by Boris Yeltsin
Boris -
I didn't explain the configuration quite right since it's not, exactly speaking, a 'curbless' shower. There's a drying area outside the shower proper but a curb 'around the corner' so to speak. Therein lies the problem.
I've folded PVC sheet membranes by the acre. Well, not really that much but I'm familiar with that approach. But that works if you have basically a rectangular shower area with all inside corners. It takes a little fussing to get the curb right but in effect, as long as you take care to seal at the drain correctly, it's not that difficult.
In this case, imagine the shower proper, a rectangular area, with a drying/dressing area outside the shower and a curb at the entrance to the drying/dressing area. Thus there are some outside corners that make a sheet membrane difficult (but probably not impossible) to fold correctly for a seamless, waterproof installation.
That's the gist of my interest in a fluid applied membrane.
I have a neighbor that's a certified applicator for so-called high end poly-urea roofing materials. That's the kind of material I'm considering using. $60/gallon is cheap if it works. You only have to have one leak to blow several hundred (thousand) dollars worth of design, tile and labor, even though the labor is my own.
I only want to have to do this once.
Thanks for the reply. I think I'll look into the Laticrete material. So long as there's an option of embeding some sort of fabric reinforcing, I think it might be the answer. On the other hand, if I buy my neighbor lunch, he said he'd be glad to install some of his material.
Test, test, and test again. If it holds water for a week, I guess it's OK to install the finish..... right! (grin)
...........
Dennis in Bellevue WA
[email protected]
This article may be of interest to you. I use it all the time and have never had a leak.
http://quittintime.infopop.cc/ubbthreads/showflat.php?Cat=&Board=howto&Number=515&page=0&view=collapsed&sb=5&o=&fpart=1
Regards
Mark
Quittintime
The problem with standard sheet membranes is this: To be thick enough to pass Code for a shower membrane, they won't hold tile on top, and have to be sandwitched between a slope and the setting bed. Where do you start and end it? And how?
The problem with liquid membranes is there is no interface between the liquid and the 2 part shower drain. None. Zero Zippo. Its not like you can paint that stuff on then clamp it down. There is a tiny piece of dried liquid. This will ultimately crack and leak. If you ignore the 2 part clamping drain, and place the liquid membrane on top of the setting bed, this is even worse, 'cause the liquid just sorta ends at the drain???
That is why I spec out the Kerdi product. Goes on top, and interfaces with their drain.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I never had a problem with the sheet membranes, Boris. If folded correctly in the corners, protected during installation of the finished wall and floor and if installed over a sloped substrate and clamped properly in the drain body, ..... that's a lot of if's, I know, but none the less, I never had one leak in all the years I installed them.
The problem, as stated in the follow-up post, is the outside corner issue and the fact that the membrane has to go "around" a partition. So the paint-on fluid applied with reinforcing fabric of one kind or another, the kind you're suggesting, is what I'll end up using.
This neighbor I mentioned earlier is an approved applicator for a high-end poly-urea coating used in industrial applications. Sewer tank linings, fish farm tanks .... etc. The samples he has shows it to be about 1/8" thick as a final complete installation. It's applied as a fluid material with a heavy weight fleece reinforcing. You could tow cars with sample he showed me!
The Laticrete system described on their web page would probably be sufficient - it's similar to the material you use; liquid application with mesh/fabric reinforcement.
...........
Dennis in Bellevue WA
[email protected]
Maybe I'm missing something here. Most manufacturers of the sheet shower pan material also make prefabbed outside corners that glue in place. (for example http://www.oatey.com/apps/catalog/showskus.asp?ctg=12&subctg=0&prodgrpid=84) Why not use the sheet stuff you're familiar with?
The problem, as stated, was that the bath was essentially curbless, and therefore if one used a traditional pan membrane, there would be no curbs to fold up to. The membrane would have to continue beyond the footprint of the shower, which is difficult to do with the slope and all.
One trick I have seen is to define the shower boundaries by spray (fairly unscientific) start the slope (and the membrane) about 4 feet past that point, and just end the membrane at that point. Once the setting bed is floated, apply a liquid membrane to the top but overlap the sheet membrane by about a foot.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
As I read it, the curb exists -- it is around a corner. However the real problem seems to be the outside corners in this complex shower pan that is inside the curb. Those outside corners can't be done with simple folds of the sheet goods. They can, however, be done with those pre-fabbed corner patches.
Jamie -
I'm familiar with folding a sheet material shower pan in an enclosed, typical rectangular shower installation. I'm not familiar with pre-molded outside corners, solvent adhesives for their installation, etc., etc.
I'm being extremely paranoid about all this, I recognize that. But as you're probably more aware of then you'd like to be, it has to be done right the first time. I can only afford to do this once! (grin).
As I noted to Boris, my neighbor is a roofing/ special coatings contractor and for the price of a lunch at our mountain greenery home, he'll mop in a high-end poly-urea commercial coating that's close to 1/8" thick by the time we're done.
Yes, you're right - there's a curb for the shower mainly to make the transition from the bath floor to the shower/drying/dressing area. By the time I grade the wet area to drain to the shower drain I'll be an inch or so above the lav area. So while a curb would not be necessary from a 'wet' point of view, it's needed to make the transition between floor levels. As well as containment in the envent of the shower drain getting clogged.
In a perfect application such as this, as in new construction, I would have addressed the depression for the shower/wet area in the floor structure. This is an extensive remodel and that wasn't possible.
Did you check out the link Boris provided for the system and material he suggested using? It is, indeed, a proper approach to the problem, especially in the case where they re-framed the floor joists to provide the added depth for the mud base and tile.
Maybe on the next house.... (hehehhe) [if my wife new I said that she'd be searching for a good divorce lawyer!]
...........
Dennis in Bellevue WA
[email protected]
I may not be getting this this but, why not treat the whole area as a wet area and install the membrane in the whole room? Any curb that you need can be molded in when you float the floor. I've done a few free-form pans that had no doors and I haven't had a problem yet by treating the whole room this way. Just pay special attention to the seams when gluing the liner material to itself.
Just a follow-up
I had my neighbor who's a commercial coatings applicator install a KemperAll waterproof membrane throughout the entire shower area. This system is similar in technique to the fiberglass system that was suggeted in one of the replies here in this thread.
With a test plug in the drain and even without the drain body clamped to the membrane, it held close to 40 gallons of water for 7 days (time elapsed between my getting back to working on it) without losing a drop.
I think I'd safe so far as the membrane is concerned!
Thanks to everyone who took the time to offer suggestions.
...........
Dennis in Bellevue WA
[email protected]
Dennis, here is the manufacturer's site. There is a video too which will give you a pretty good idea of what's up with this stuff.
http://www.schluter.com/english/products/2002/sectionf/kerdi/801-index.html
Does anybody use that BUTTUGLY plastic corner bead they make?
Joe H
Yes, I have used it. It is nice in a commercial application. It is also nice as a floor cove. The stuff is plastic, albeit hard plastic, and nicely dyed to match most tile colors. It is supposedly UV rated so it won't yellow. It looks cheap (like those plastic quasi tile sheets), so in a commercial context it would look fine.
I just used it in a residential floor wall transition where the floor tile and stock cove didn't have the same thickness and I either had to use it or carve some sort of channel in the mud bed for the over thick cove. What a pain in the A S S. I think if I had to do it over, I would just use the oversize coves and do some sort of workaround.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
This is a very Scandinavian design idea. Over there, the whole bathroom is tiled, there's a floor drain someplace, and the shower is in one corner with no curb.
-- J.S.