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I am about to build a steam shower and realized I need a vapor barrier.

I am using a mortar bed floor and am coating the entire shower with Hydro-Ban. There will be shampoo niches, lots of valves and sprayers on the ceiling as well.

How do I seal a vapor barrier around all of those penetrations??

How do I get a vapor barrier behind the hardi backer to overlap the Hydro-Ban membrane on the floor?
 

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Tile And Stone Contractor
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To properly apply a vapor barrier to a steam shower, use the following.

Once you have your PVC pan liner in the shower floor area, drape solid sheeting of plastic across the stud. Do not break the sheet into two or more pieces if possible, but instead, use a solid piece. if you must segment it, use a good tape (duct tape), and seam the segments. Make sure the plastic drape is dropping INSIDE..... INSIDE.. of the shower pan material for the shower floor. Then drape the ceiling studs with additional plastic sheeting, making sure it also falls INSIDE.... the wall drapes. Cut the openings for the pipes/body sprays, etc and close up with silicone caulk or duct tape. Hang your cement board to studs/plastic. Be sure to seam all joints with fiberglass tape and fully modified cement/thinset. You could then apply an additional treatment of RedGuard Waterproofing. I usually apply a two coat process, 1 direction, dry time, then 1 in the other direction. Never use a framed seat in a shower. You should make sure to use, instead, a cinder block seat, built inside the cement board walls, and make sure you drape shower pan material in the wall 2' high to prevent any runoff.
 

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Tile And Stone Contractor
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I've never used kerdi system, although I've used a lot of schluter products

regardless of which waterproofing you might use topically, you still need a vapor barrier behind all the wall substrates (cement board) that drains inside the shower pan material.
 

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No vapor barrier with kerdi, once you usethe kerdi especially in steam rooms you will never look back, they are coming out with kerdi panels like wedi panels even faster as you only need to do the seams and screw heads.
 

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my guess is the kerdi system isgoing to be exponentially more expensive than a roll of plastic, tar paper, and/or a gallon of RedGuard. I generally stick with what works. I'll look into kerdi, though...I'd be curious how much it cost and how long it takes to install. I can rough in vapor barrier, walls, seams and a coat of redgaurd in a single day. I dont' know how kerdi could be any more expedient.

Update
Kerdi sheeting looks like it goes over the cement board. it also looks expensive-thus cost prohibitive, considering Noble Seal sheeting works the same at around $3-4SF. I'd definitely use a plastic vapor barrier and RedGuard. I wouldn't trust sticking to a sheeted material, not to mention, its way more work and way more expensive.
 

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I'd definitely use a plastic vapor barrier and RedGuard.
I'd be interested in a spec showing your proposed system.

my guess is the kerdi system isgoing to be exponentially more expensive than a roll of plastic, tar paper, and/or a gallon of RedGuard.
...it also looks expensive-thus cost prohibitive...not to mention, its way more work and way more expensive.
From your own signature, "The bitterness of poor quality last far longer than the sweetness of a cheap price". (anonymous)


Continuous (meaning not liquid) SA membranes are far superior to the poly, felt system, especially in a steam room. Even a liquid membrane is better, but subject to getting proper coverage and mil thickness to be effective.
 

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I'd be interested in a spec showing your proposed system.





From your own signature, "The bitterness of poor quality last far longer than the sweetness of a cheap price". (anonymous)


Continuous (meaning not liquid) SA membranes are far superior to the poly, felt system, especially in a steam room. Even a liquid membrane is better, but subject to getting proper coverage and mil thickness to be effective.
Are you attempting to discredit my professionalism? ^^^^^^^^ LOL....Using cost effective materials is one way of keeping cost down for consumers seeking a great job at a great price., Using expensive membranes in a steam shower only reflects additional cost to consumers. I have a spotless reputation with the Better Business Bureau and have extensive union experience in the tile and stone trade. My credentials in tile and marble are vastly superior to the average hacks I find myself in competition against. I dont' find anything cheap about using RedGuard. At $100 gal, I'd say it's not exactly cheap, but I'm not over killing a steam shower with $600-800 for a membrane. Question is, what did we do before membranes? I follow old school, time honored methods and add in redGuard. It's overkill anyway if you have properly installed the vapor barrier.

Main page
http://tileusa.com/faq_main.htm
Specific reference
http://tileusa.com/steamroom_faq.htm


ok looks like my attempts to upload a photo image of TCNA source code book is routinely failing. Suffice to say, in addition to slip joints and sloped ceilings, it calls for a waterproof membrane behind all wall surfaces.

Even surface membranes require a vapor barrier, so I guess the debate ultimately falls on the topical surface preparation- liquid waterproofing, vs membrane. I've had good success with RedGuard and stick by it, provided adequate mil thickness is achieved.

As for a spec, I described in my opening post how to install a vapor barrier. Tar paper, properly draped, would also suffice, but I find heavy mil plastic much easier, lighter, lower in cost, and just as effective. I can't see spending $600-800 for a membrane when 2 properly applied layers of Redguard works every bit as well. I would stipulate that it's best to skim coat all cement boards with modified thinset prior to applying RedGuard to prevent surface dust from preventing a bond.

besides, the OP stated he was using Hydro-Ban. His original concern was about installing a vapor barrier, which I believe I covered.
 

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To properly apply a vapor barrier to a steam shower, use the following.

Once you have your PVC pan liner in the shower floor area, drape solid sheeting of plastic across the stud. Do not break the sheet into two or more pieces if possible, but instead, use a solid piece. if you must segment it, use a good tape (duct tape), and seam the segments. Make sure the plastic drape is dropping INSIDE..... INSIDE.. of the shower pan material for the shower floor. Then drape the ceiling studs with additional plastic sheeting, making sure it also falls INSIDE.... the wall drapes. Cut the openings for the pipes/body sprays, etc and close up with silicone caulk or duct tape. Hang your cement board to studs/plastic. Be sure to seam all joints with fiberglass tape and fully modified cement/thinset. You could then apply an additional treatment of RedGuard Waterproofing. I usually apply a two coat process, 1 direction, dry time, then 1 in the other direction. Never use a framed seat in a shower. You should make sure to use, instead, a cinder block seat, built inside the cement board walls, and make sure you drape shower pan material in the wall 2' high to prevent any runoff.
Are you specifically considering the plastic behind your tile substrate as a vapor barrior and your red guard in front of your tile substrate as a water proof barrior?

To me the best system is to keep your waterproofing/vapor proofing on top of the tile substrate, keeping the moisture on one side of things.
 

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Tile And Stone Contractor
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Are you specifically considering the plastic behind your tile substrate as a vapor barrior and your red guard in front of your tile substrate as a water proof barrior?

To me the best system is to keep your waterproofing/vapor proofing on top of the tile substrate, keeping the moisture on one side of things.
Both.

A vapor barrier lives behind the substrate, to prevent moisture that is being "forced" into the room from penetrating adjoining walls. A steam room is an airtight environment and moisture will penetrate grout AND cement substrates. A properly installed vapor barrier keeps this moisture contained, and properly drained into the shower pan liner. IOW's using a vapor barrier properly was how a steam shower was installed "before" we ever had membranes or liquid waterproofing. Using a vapor barrier AND RedGuard or other membrane waterproofing is esentially overkill, but either membrane or liquid would work fine. I just can't see spending countless hundreds for membranes when what's really important to keeping the adjoining areas dry is a vapor barrier. I stick with what I know and what has worked for me. I have steam shower clients of 20 yrs who I still communicate with and have never had a problem. RedGuard and membranes are more designed for people who aren't familiar with vapor barriers. If you have a good barrier behind your substrate, there's no worries.
 

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There's a great deal of debate in the tile community about the use of vapor barriers with various membranes and substrates--particularly with surface waterproofing liquids. There is a significant risk of a "moisture sandwich" when combining different systems and care should be taken to investigate the specifications of the products you're using.

As Mike said, keep the water and vapor on one side.

I highly recommend you look into the Kerdi system. While it's material cost is higher--it more than makes up for it in labor savings and longevity.
 

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I have to repeat the question -

Are you specifically considering the plastic behind your tile substrate as a vapor barrior and your red guard in front of your tile substrate as a water proof barrior?

Let me be more specific - To me the best system is to keep your waterproofing/vapor proofing on top of the tile substrate, keeping the moisture on one side of things. (avoiding sandwiching moisture between the two barriers.)

I know there is felt a distinction between vapor and liquid water, but essentially they are moisture.

The water proof barrier (red guard) would keep sprayed water from penetrating the red guard (water proof barrier), but if red guard isn't a vapor barrier you are allowing the vapor to penetrate it, turn to liquid and be trapped behind it now since it isn't going to go through the vapor barrier and it won't go back through the water proof barrier now, and it certainly all won't drain down and out through the tile membrane.

I would propose considering the issue of clear glass tile installation in a steam shower to illustrate the issue even if it's not the issue of seeing the darkening behind the glass, it does illustrate the moisture issue exists and can only be solved by keeping the moisture/vapor barrier on the wet side of the tile underlayment.
 

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I think it probably turned out like sh*t or he is living with the original mess, cause once I gave him the numbers I took his visible choking and gagging to mean he was thinking that redoing something installed wrong the first time should be cheaper then what it cost to do it wrong the first time. :no:
 

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Paul,

I have the current TCA and and is not spec'd in it. Poly behind the cbu and redguard on the face is a double vapor barrier. Plus, doing both is redundant and can be problematic, especially in a steam shower if penetrations aren't carefully detailed. The vapor, if it gets through the membrane, will saturate the backer, then hit the poly.

Also, a SA membrane is a vapor barrier as well as waterproofing. SA membranes cannot let moisture pass into the stud cavity, therefore it does not contribute to excess moisture in the wall. If you are using plastic film or 15-pound tar paper behind the board to waterproof a tub/shower, do not be surprised if your customers encounter problems with mold, mildew, leaks, etc.

Wicking is also a problem with all mortar bed showers made without surface-applied membrane systems.

If you are using redguard or similar, I would be doing at least 3 coats to ensure complete coverage and proper mil thickness. Even though many claim 2 coats for waterproofing, you will most likely need 3 or 4 for it to be completely effective.


BTW, I get Kerdi for $1.24/SF.
 

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Too bad hammerswinger didn't get this kind of response a month and a half ago. :whistling


When it comes to waterproofing in a shower, steam or otherwise, it's a "perm rating" that determines the difference between vapor retarder or barrier. Look at the perm rating of any material you're considering before thinking you are actually waterproofing something. If it's over 1, you're not building your wet location sufficiently. :no:
That goes for ANY sheet membrane or liquid barrier. All are not created equal.

The inherent issue with a plastic vapor barrier on the back side of the wall board material is that it is mechanically fastened to the studs. What do you think that does to it's "barrier" quality? :blink:

Folks can still build showers (of any kind) with CBU and a vapor barrier behind it and pretend they have an actual waterproof shower.
 

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The inherent issue with a plastic vapor barrier on the back side of the wall board material is that it is mechanically fastened to the studs. What do you think that does to it's "barrier" quality? :blink:.
Another good point
 

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=Shawn Prentice;868241]Paul,

I have the current TCA and and is not spec'd in it.
Actually it does specify a layer of waterproofing behind either cement board or cement mortar bed walls. 2003-2004 41st edition, TCA Manual, pg 39 (steam showers- sr613-03)

Poly behind the cbu and redguard on the face is a double vapor barrier.
the poly works as a safe guard. Even with sheet surface membrane, leakage could occur. With either liquid or solid membrane, I'd rather have a safeguard in place (poly) than risk a possible leak. Even with solid membranes, if they're not installed properly, there's nothing to stop water from passing through.
Plus, doing both is redundant and can be problematic, especially in a steam shower if penetrations aren't carefully detailed. The vapor, if it gets through the membrane, will saturate the backer, then hit the poly.
Also, a SA membrane is a vapor barrier as well as waterproofing. SA membranes cannot let moisture pass into the stud cavity, therefore it does not contribute to excess moisture in the wall. If you are using plastic film or 15-pound tar paper behind the board to waterproof a tub/shower, do not be surprised if your customers encounter problems with mold, mildew, leaks, etc.
Prior to the advent of todays technology, steam showers were built with tar paper/poly and mud walls over lathe. The preventive source of protection was the vapor barrier.



The inherent issue with a plastic vapor barrier on the back side of the wall board material is that it is mechanically fastened to the studs.
Tar paper and/or poly sheeting behind lathe/screed mud walls were used 50 yrs ago. I'm unclear how something that worked then is no good now. :blink:
 
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