Tundra, to the best of my knowledge, Hydroban liquid membrane has never been approved as a stand-alone membrane in steam showers. Its perm rating is too high. Good for waterproofing but not vapor-proofing. The last time I read the Hydroban pdf was maybe a year ago, then the fine print said something like "...approved for use in a steam shower when used in conjunction with a vapor barrier...".

Yes the poly being a safety net , I am pretty sure they designed it to NOT allow water between hydro and poly soaking the CBU I would have thought you knew that Mongoct??

keep twisting things around as you see fit whoever you are ????

cataan, I'm not a fan of two membranes in a shower pan, even when one is vapor permeable. Sometimes it's the better solution in repair and remediation, but in new construction? It's simply unnecessary.

If you go with the PVC membrane, then do as Bill recommended. Make sure the membrane itself is sloped. Over the subfloor, usually a slip sheet and a layer of expanded diamond mesh. Then a preslope of mud pitched to the drain. Then PVC membrane on top of sloped mud. Then another layer of mud on top of the PVC membrane as your tiling bed.

However, it's much simpler to just do a sloped bed of mud over the subfloor with a HB drain set in the mud bed, and then cover the sloped mud with Hydroban, etc.

Thanks Mongo - for the hydroban version are you saying don't use any cleavage membrane to prevent the plywood subfloor from taking water out of the mortar?

cataan, whenever I do a mud slope or mud preslope on a wood subfloor, I install a slip sheet and diamond mesh. So for the HB version I still recommend them between the subfloor and mud.

Sorry about that.

Just a simple, 0.3 mil plastic sheet? Something that isn't waterproof but will prevent short term drying of the mortar by the plywood?

Any plastic will do. I usually use either 6-mil poly sheeting, or #15 felt. It's intended to keep the mud from bonding to the wood subfloor ("slip sheet"). As you noted, it also would prevent wicking of moisture and poly would be better at that than tar paper, but deck mud is pretty lean on moisture to begin with. But either is fine.

Set your slip sheet material on the subfloor. Over that lay expanded diamond mesh or lathe. Staple as needed (through the mesh and the slip sheet, into the sub floor) to keep the mesh from curling up. Pack the mud on top of the lathe.

If you're going the Hydroban route (sheet membrane or liquid membrane), have the drain (Laticrete or Kerdi-style fleeced drain) on hand. You'll set the drain as a part of building your mud slope.

Best, Mongo

Back BEFORE they first came out with Hydroban, Laticrete invited a bunch of local contractors to their Main office in Bethany, Connecticut, to brainstorm re what they would want from a new waterproofing. At the time, my sister was a project manager working for Coastal Tile in North haven, and being that we basically grew up with the Rothbergs (my grandfather was the first to ever make a retail purchase from Laticrete in 1956 and my father was a good friend to Henry Sr,-- the gentleman who invented latex additives) we're still pretty close, and she was one of the contractors invited. She called me that afternoon, and asked if I had any input. I told her to ask them for a trowel on waterproofing that had a low enough perm rating to use for steam showers. At the time, it was either Kerdi or Hydroment's Ultraset, as far as I was concerned. When they came out with the Hydroban, I contacted Art Mintie (the head of their tech department), and I was told that a separate vapor barrier was still needed. Now, if they've changed the spec since then, I don't know. But if I were you, I'd call their tech department on Monday and verify your information. 800 333 9235

cataan-- sorry about that! Sometimes it's tough to tell in here. LMAO

Tundra wrote:

"Yes the poly being a safety net , I am
pretty sure they designed it to NOT allow water between hydro and poly
soaking the CBU I would have thought you knew that Mongoct??

keep twisting things around as you see fit whoever you are ????"

Unfortunately, I don't understand your comment. Or what I supposedly "twisted around".

Seriously, I'm not trying to give you or anyone a hard time. I thought my post was pretty straight-forward.

I got the impression you only used Hydroban liquid membrane as the only barrier in your steam shower. If you used HB in conjunction with a true vapor barrier somewhere else in the assembly, then that meets the requirement.

The first time I used Hydroban was over a decade ago I'd guess. Even back then it wasn't rated as a vapor barrier.

Sorry if my post caused any confusion.

Bill wrote: "Hydroban liquid is NOT rated for steam. Only the sheet membrane..."

Bill, you brought up an important point for me. I have to remember that I can't just write "Hydroban" anymore. It'll now have to be "Hydroban Liquid" or "Hydroban Sheet".

Old Dog.

New Trick.

Ruff.

Yes Mongoct and Bill you finally got it right.

You do need a poly vapor barrier with the hydro liquid in a steam shower build So yes you both are correct.

i believe now with all the new membranes theres smarter ways to build but lets not mislead anyone reading OK!

Just to be clearer This steam shower build i posted above was spec and approved by both Laticrete and Noble and includes a poly barrier. My field rep and at HQ.

Since I i no longer use Hydroban I now build full spec Noble steam showers with sealed slip joints to the Noble spec.

thanks for youre creative spin on words both of you .!!!!

Tundra,

My comment arose because you wrote:

"Um Bill I have 2 Hydroban steam showers currently functioning well
after years of use? Hydroban liquid steam showers approved by Laticrete?

They may have "now" changed spec to Membrane But yes its used In
vapour steam environs and they still warrantee the older installs ? am I
wrong please do correct me as I respect your word........???"

There was no mention that you used a poly vapor barrier along with the Hydroban liquid.

I took your post literally. As you wrote it. No spin.

The concern would be if a DIYer or perhaps even a contractor read your post and inferred that "you can use Hydroban liquid membrane in a steam shower" and went ahead and did just that. And only that. With no true vapor barrier added in addition to the Hydroban liquid, which is required. It's very much along the same lines of my earlier post to cataan I wrote:

"If you go with the PVC membrane, then do as Bill recommended. Make
sure the membrane itself is sloped. Over the subfloor, usually a slip
sheet and a layer of expanded diamond mesh. Then a preslope of mud
pitched to the drain. Then PVC membrane on top of sloped mud. Then
another layer of mud on top of the PVC membrane as your tiling bed.

However, it's much simpler to just do a sloped bed of mud over the
subfloor with a HB drain set in the mud bed, and then cover the
sloped mud with Hydroban, etc."

I created a point of confusion for cataan because I didn't include the recommendation for the slip sheet and expanded diamond mesh in the second paragraph.

There's no spin. Just trying to achieve clarity. That's all.

OK Thank you Mongoct.

Mogoct said:

"There was no mention that you used a poly vapor barrier along with the Hydroban liquid.

I took your post literally. As you wrote it. No spin."

Maybe You mean to say you wrongly assumed a point i didn't touch on .... and further confused folks reading......... maybe it wasn't intentional and im out of line....

I stated Approved by Laticrete as they did MARKET LIQUID hydroban for steam showers ( residential use ) but just like using it as a shower pan liner its a risky build and i would not reccomend it to A first time DIY like cataan or at least caution him and nudge him in a better direction now with the Fleece membrane s.........no detailed mention of how i built my steamer was spoken of or implied.

Finally,

I saw it as you and Bill misleading readers that It cant or never was approved for steam showers which I believe are indeed a vapour environment, which is simply misleading and WRONG........

We are getting way off topic now and poor cataan just wants a quality shower and like many homeowners is getting lost in a sea of bad info and clearly trying to find someone to guide him and maybe that someone is you and or bill..

I was trying to help him and even help him using Products I no longer use in my showers yet I respect Laticrete even with all the issues ive had with my local laticrete people. Im still helping promote their materials.

Thanks for your clarification ill take it as genuine.... Mongoct

One big internet hug to Bill who is here with his business name at stake and who's opinion and years of tile expertise I can respect.

I think all of you provide great words of wisdom and all have good intentions too. It's easy when typing to miss a word or forget to include something, or to assume something that is obvious to some but not to others. None of that means someone is being deceptive or trying to mislead - miscommunication is inherent in communication. So high fives to everyone on this board because I appreciate learning from your experience in the field. What I do find interesting is that there is really a lot of technology in the housing remodeling field, but so many contractors do not keep up with it. Generally, but of course not always, technology makes things better and easier, so I don't know why more of this isn't mainstream among those who work in the field (e.g. newer waterproofing materials like kerdi and hydroban; newer support materials like ditra, etc.)

Mongoct said : '' The concern would be if a DIYer or perhaps even a contractor read your
post and inferred that "you can use Hydroban liquid membrane in a steam
shower" and went ahead and did just that. And only that."

May I remind you that it is the responsibility of the user -- -- DIYer or Contractor or ........ -- -- to check the specifications , technical details ,etc. of the product usage for the specific application .

A few examples of the specs :

Laticrete quote :

'' Obtain approval by local building code authority before using product in shower pan applications. ''

" Specifications are subject to change without notification. Technical data shown in LATICRETE product data sheets and technical data sheets are typical but reflect laboratory test procedures conducted in laboratory conditions. Actual field performance and test results will depend on installation methods and site conditions. Field test results will vary due to critical job site factor. ''

Among other things .........

Well said Eurocerob and Cataan....

Eurocerob, no reminders are necessary, but your point is certainly appreciated.

It's just that there are so many screwed up installations out there because not all people, be they DIYers, contractors with the best of
intentions, or hack fly-by-nighters, read instructions.

If this was a peer-to-peer forum, I'd certainly agree. But it's not the pro hangout at JB, it's not JLC, it's GardenWeb.

Often times on these forums we're dealing with homeowners who had the unfortunate circumstance of hiring someone resembling the lowest common denominator. So when dealing with a question from a homeowner or a DIYer who may not understand the "lingo" that is included in a manufacturer's installation instruction PDF, I tend to get a little wordy and I try to talk more in specifics than in generalities when talking them through a process.

Heck, at times even the AHJ has it wrong.

My apologies guys and girls. My intention is not to rub anyone the wrong way. I'm not trying to throw anyone here under any bus. Seriously.

I did not mislead anyone. I stated Hydroban liquid does not have the perm rating to be considered a vapor barrier. If you use a poly vapor barrier behind it, that kind of solves that problem, doesn't it. The point I was making with cataan was that it would NOT trap moisture into the shower pan if there was a liner underneath and liquid Hydroban on top, and therefore no moisture sandwich. however with the Hydroban sheet membrane, it DOES have the perm rating, and therefore WOULD cause the moisture sandwich.

Thanks bill for clarifying

IM gonna have to further disagree that its not smart to have a 2 liner pan system and that it very well could breed mildew if water gets in betweeen and yes even with weep holes and perm rating.

being that the liquid itself is used to stop water from getting to the shower pan, or the backer board as its sole purpose

but hey thats just my one common sense viewpoint...

no disrespect, disagree maybe!

It's not the best situation, for sure.

If you use hydroban SHEET membrane on top, should you still use the plastic sheet for a cleavage layer between the plywood floor and bottom of the mortar base to prevent the plywood from sucking the moisture out of the mortar bed? It's kind of a catch-22: you don't want the plywood to interfere with proper formation and drying of the mortar bed, but you don't want to end up with a mold sandwich. I prefer turkey with provolone, grilled banana peppers, dijon mustard on one side, pesto on the other side, with lettuce and tomato. Mmm...

Either plastic of tar paper.

Felt paper was used for decades to protect the plywood or wood planks from getting in contact with the mud floor . It should not be a problem to use it under the mortar base if you decide to use the Hydroban sheet membrane .

Hey guys quick question - if I go with the dual membrane (pvc liner on pre-slope + hydroban on top bed) and standard drain (not laticrete drain), is there anything special that needs to be done in using the hydroban around/on the drain?

You can seal it to the side of the drain, if you like.

"Anything Special." Well you should make sure that you don't seal the Hydroban to the adjustable strainer. Since the pvc liner is the primary waterproofing the Hydro ban is just the back up. But if you seal the hydro ban to the strainer the strainer now becomes a dam so watch out you don't do that.

A standard drain is a three piece clamping drain in my example. I hope that is the question your asking....

Thanks guys - so it's simple just make sure the top of the drain/strainer is free of any hydroban liquid? I had read posts saying something about it being complicated to use a standard drain rather than a Kerdi or Laticrete drain.

That is if you want to tie Hydro Ban into a clamping drain. A pvc liner is almost always used with a clamping drain. I would use a sealant under the pvc and above the bottom portion of the clamping drain.

NobleSealant 150 and Noble's Chloray liner is excellent quality. This would be a good start for the basic waterproofing. Remember you need to have pre-slope first. Then the liner. Then a flood test. Then all the water should drain away.

I use some Ditra Drain and Noble's Weep Hole protector to provide water movement under the mortar bed. Ardex has a new decking solution that will replace the Ditra Drain in my upcoming jobs. Anything can wok really. Strata Mat, Hemp Cord, Fishing Line, Candle Wick. Something to provide better water management under the mortar bed.

If you set the mortar bed with Laticrete 3701 you should wait 3-7 days before applying the Hydro Ban. If you use standard 4-1 I would wait a good 4 weeks.

The double layer approach is very common from Mapei - they talk about it often in their training classes but I have not heard so much chatter about this from Laticrete.

Premium 40 mil waterproof liner

Check out the Noble Company videos on this product. make sure you get a couple dam corners and a weep hole protector....

So, how are you guys attaching the poly sheet to the studs ?

Adhesive ?

Staples? Are they stainless steel staples?

Are you taping all of the joints with tape? What kind ?

How are you detailing the penetrations for the valve and outlets.

Is that plastic melting around the steam outlet when it gets fired up ?

This is for a regular shower! Since I am going with a traditional pre-slope/slope build + Hydroban, is there any reason I should or should not use Laticrete 3701 for the bed and Platinum for the thinset?

"...is there any reason I should or should not use Laticrete 3701 for the bed..."

I don't see a need for a sloped bed of 3701. It'll be less expensive, and in some ways more appropriate, to simply use deck mud (5:1 sand:portland).

I recommend you take the money you save from using deck mud and putting it towards a Laticrete or Kerdi drain. That way you get a "topical membrane drain" to go along with your topical membrane.

You can use a clamping drain with a topical membrane. But why do it? Trust me, I'm not profligate by any means. But I'd save money by using deck mud instead of 3701 and spend the savings on a Laticrete/Kerdi drain.

Do understand, this is simply my opinion. If you feel strongly about choosing another path, by all means, feel free to do your own thing.

EDIT: Disregard the above. I thought this had been changed to a "Hydroban only" shower.

Hey Mongo - this is a question of ignorance, not disagreement: why is the laticrete drain better than a standard clamping drain? Given the two-membrane method I am using, is it installed just as it would be using the laticrete 3701 single slope method?

Frankenstein's monster. Pick one methodology from one manufacturer and stick with it. This is a train wreck.

"Given the two-membrane method I am using,"

Cataan, my apologies. I thought you had gotten away from the two-membrane system and that you were just doing a single-membrane, HB shower. Disregard my previous post. I'll add an edit to my previous post to prevent confusion for anyone else reading.

If you're still using a PVC liner for your membrane, then sure, use a clamping drain for that membrane. Any time you use a liner like that, you are correct, you want the liner to be sloped. So preslope, then liner on the preslope so the liner itself is sloped, then tiling mud on top of the liner.

I will say that with this being new construction, I think the two membranes are unnecessary. I'd recommend picking one or the other. There's really no synergy to be found here.

I don't do install multiple membranes like you are proposing. I could see it when repairing or partially repairing a liner shower. But for new construction?

Hydroban is vapor-permeable. So as Bill (I think it was Bill) wrote earlier, you CAN do what you are proposing. And with one vapor barrier, technically you're safe. But as a "best practice"? It's not something I'd recommend. Again, that's simply my opinion.

Since this is not something I advise, I'll bow out and leave the advice to the others.

Best of luck with your shower.

"This is for a regular shower! Since I am going with a traditional pre-slope/slope build + Hydroban, is there any reason I should or should not use Laticrete 3701 for the bed and Platinum for the thinset?"

These are my favourite shower building products.

You missed out the 16 gauge 2"x2" galvanized mesh from the equation. This should be left outside and checked for no rust issues. In the US it seems so many people struggle finding this product.

Remember leave the base dry out a good 3-7 days before adding Hydro Ban. AND DO NOT seal the Hydro Ban to the adjustable strainer.

What are you planning for weep hole protection? Have you ordered a Noble Company Positive Weep Hole Protector?

Have you see the work I'm doing with drainage mat and weep hole protection? It is the opposite of your plan. I am not trying to block water getting the the mortar bed I'm giving it a road way under it to the drain. This is my newest goto shower building practice for the last couple years. I like the showers so far and like more the theory behind my design.

In your case I might add a drain mat around the strainer and keep the Hydro Ban back from this about an inch or so. I might add as well some mesh to prevent the drainage channels from blocking. This way you have a faster drop for moisture to exit the shower once it weeps to the drain location.

You can see some of my work here:

Laticrete 3701 Fortified Mortar Bed Install

The weep hole protector is not in at the moment but the drainage matting is in place around the perimeter of the shower and to the drain. Later the weep hole protector gets installed. Then the ACO linear drain.

Slurry coat is Laticrete 254 Platinum

Mortar bed is Laticrete 3701 ready mix

Back in the day plumbers pulled candle wick or hemp cord to the corners. Then that degraded over time leaving roadways for water. My way I think is better and ensures there is always an easy gravity trail for water without the mortar bed in the way.

I do not think our setting materials allow moisture migration like they did years ago. Too much crap in them now.... My thoughts.

Im with Mongo on bowing out, and Touch'e to Sophie bringing the real heat!!!

John did NASA approve that install !!!!! wowzers what a pan.

Wow, you guys are craftsmen. To a noob like me you just think put down mortar, slope it, waterproof it with some stuff, set tile. There is SO MUCH to constructing a shower; it's a form of engineering to be honest.

" To a noob like me you just think put down mortar, slope it, waterproof it with some stuff, set tile."

I just have to comment. Funny thing is, that's exactly what you could be doing.

Deck mud sloped bed with a laticrete/kerdi drain.

Then Hydroban.

Then Tile.

Then grout.

Then Done.

It really isn't that complicated. lol

"Not complicated" doesn't necessarily mean "easy". It really just means "do the steps one at a time, and do them well. No shortcuts. If you bugger it up, start over."

Do not accept mediocrity.

"If you bugger it up, start over." Yup. Repeat that mantra till you get it. Then read this thread again. And have the courage to start over.

I am just concerned that not having the back-up liner (e.g. chloraloy) is risky because of the chance that there is an issue with the hydroban liquid at some point. Seems "safer" to have the chloraloy liner at the weep hole level followed by hydroban on top of another layer of mortar. But, of course, this is more work which means more chance of messing something up.

cataan, I get it. The thing is, with shower pans, more is not always better.

You can get an "excellent shower" with liquid Hydroban. But adding more layers does not necessarily mean you now have a "more better wicked excellent shower".

Hydroban liquid is a terrific product. I've used it. I trust it. But I'm also a guy who reads instructions. I follow instructions. But I can also shift gears and modify my practices if need be based on the conditions at hand. And if you need it? Tech support for these materials? It's only a phone call away.

If you have a good smooth deck mud slope to apply it on, if you follow the installation instructions, you'll get a fine installation. Heck, you can even add additional coats of HBL if you want to have added insurance. A $5 mil-thickness gauge will give confidence that you're not over- or under-applying the liquid.

But I'm not here to sell you on HBL.

My larger question to you would be if you don't have confidence in Hydroban liquid, then why even use it in your shower in the first place?

In a simple "A" versus "B" comparison? I do recommend topical membranes over Chloraloy-type membranes. But there's nothing wrong with a properly installed Chloraloy-type shower pan. Topical membranes are terrific at managing/eliminating moisture penetration into the shower structure. The "old days" of walls made of poly sheeting behind cement board and pans made from CPVC membranes buried under an inch of mud? They were fine. They're still fine. But if you can use a topical membrane throughout your shower, it can be a better option.

The "old way" is still fine though. And appropriate.

There's more than HBL out there. If you don't have confidence in HBL, the use a sheet membrane, but only if you omit the Chloraloy due to the two vapor barrier issue. You can use Hydroban sheet membrane (or some other equivalent). Laticrete, Nobel, Schluter, etc, they all make great membranes. I don't recall if you were using HBL on the walls, but if you are, then I'd stick with Laticrete throughout.

Is there any reason in particular that you're leery of HBL? The only bad installations I've seen are folks using it over a poorly detailed, pockmarked mud bed, or where it's been applied hastily and it's been overworked, and air bubbles resulted. There was that installation about a year ago where someone tried to use about a half-gallon to cover about 150 sqft. That type of stuff.

There are a lot of good videos out there on the interweb. Some bad ones too. But problematic installations are usually caused by the installer. Ignorance? Apathy? Ineptitude?

But I'll go back to what I've said in my previous posts. The above is simply my opinion.

If you really want a double membrane, then by all means do it. And if you go that route, Hydroban liquid is the least risky choice for the topical membrane portion of your build because HBL is vapor permeable.

I just wrote a long reply. Trust me, I'm not trying to beat you over the head, especially since what I wrote was my opinion. lol I just want you to be informed, or to at least see a different perspective. In the end, it's YOU that needs to be happy.

Good luck!

Hey Mongo - I think it's not so much whether I trusted HBL, it's fear of bad luck! I had thought about sheet only over 3701 and called Laticrete. Interestingly, the Laticrete tech guy suggested using liquid rather than sheet since it is easier to install. He pointed out that the sheet has to be flat yet also conform to the slope, and if I've never used a sheet before it might be difficult to do, thus ending up with air pockets. If it really isn't that big a deal I'd be happy to use the sheet and skip the pre-slope.

Yeah, I get it. With the horror stories I read on the forums and the bad showers I've seen with my own eyes? It can be scary out there. lol.

I've never had an issue with sheet membrane conforming to a sloped mud pan. Never had an issue with wrinkles, etc.

I don't post many project photos, I think I've only posted one set from a sheet membrane shower and that was a Kerdi shower "how to" that I built probably a decade ago. If you want to see pics, do a search for "Kerdi Shwer Part Deux". About half of the photos on the thread didn't make it through the GWeb-to-Houzzzz transition, but the ones of the membrane going down over the mud pan are there.

I watched a video showing kerdi install over mud bed with kerdi drain - is the hydroban sheet with hydroban drain pretty much the same thing except that you put some hydroban liquid on part of the drain? If so it looks *very* easy. Schluter does a wonderful job of providing instructional videos - Laticrete is very slack in that regard; I can't find anything showing how to install the sheet membrane with the hydroban drain - only for the liquid hydroban.

"....is the hydroban sheet with hydroban drain pretty much the same thing except that you put some hydroban liquid on part of the drain?..."

Pretty much the same but the Laticrete products come with less restriction and the membrane itself is better. Better in that it is thicker. Better in that it is less permeable.

I think Laticrete even allows people to switch to their membrane with a kerdi drain installed.

"....Laticrete is very slack in that regard; I can't find anything showing how to install the sheet membrane with the hydroban drain - only for the liquid hydroban."

Email Arthur Minte at Laticrete. Ask him for some pointers. amintie@laticrete.com When I ask the tough questions of Laticrete he is the guy I get sent too.

Thanks John - emailed Arthur and he confirmed my plan.

Your welcome. Arthur is the goto guy. Glad he could help.

Here is their detail for regular showers when using a strainer drain (as opposed to a flanged drain).

And why would you promote that detail ?

Just can't bring yourself to spend $100 for a hydroban flanged drain ?