203K construction debacle - to vapor barrier or not to vapor barrier

[ncraig]

So ive been fighting with a contractor for almost 6 months now on a major home renovation. One part of the renovation was a complete remodel of the master bathroom to make an ADA compliant walk-in shower.

I found out AFTER the last tile was set and grouted that they never installed a vapor barrier behind the Durrock CBU in the shower. The argument from me is that it has to be there, or a exterior CBU membrane (kerdi, redgard).

Because the shower is complete they are refusing to fix it.
here is thier final response:
8. No vapor barrier in shower. Not a code issue. None of the manufacture’s of the products used mention the use of a vapor barrier nor is it an industry standard. Please go to USG's Website and watch the video on the installation of Durock Cement Board. It shows them installing the cement board directly to the wood studs exactly as what was done in the residence. At no time does it mention or show a vapor barrier being installed. This is the manufactures recommendation. Also The Tile Council of North America's own handbook does not specify that a vapor barrier is needed when installing these items. No work to be done.

My TCNA handbook is outdated from 2011. can anyoen provide hard references to fight this scourge?

[ddmoit]

Welcome to the forum, Nick.

Technically, a "vapor barrier" is not required. Now a "moisture barrier" on the other hand - that's debatable.

Here is a relevant thread to look at.

http://www.johnbridge.com/vbulletin/...ad.php?t=99616

[ncraig]

USG does not require the use of a vapor barrier behind Durock in tub/shower enclosures. But, we always defer to the local Building Codes for these installations.

Our position is that a properly installed tub/shower enclosure using Durock and all the required accessories, a quality tile job and quality grouting job will give you, in effect, a water proof membrane. However, we also recognize that there are Installers out in the field that cut corners and do not use the accessories that USG requires in order to obtain the optimum installation.


*** sounds more like a cop-out than an response.

[ddmoit]

It's fair to say that most of the folks here would have advised a moisture barrier in your shower's construction. It may however be the case that all manufacturer's installation instructions and applicable codes were followed. Not ideal, but it may never end up being a problem in your lifetime. Then again, it might.

[cx]

Look on page 161 of your 2011 TCNA Handbook, Nick.

[dhagin]

That thread Dan linked to has all the info, but let me try and boil it down for you.

1- What does your contract say about it?
2- What does your local building code say about it?
3- USG does not require it. Their install & tech info is on their website.
4- Industry standards do require it. ANSI & TCNA both reference membranes either behind the backer board or on the surface. There are a number of options here, but one or the other is required.

[ncraig]

i don't argue with anyone of you, i would ALWAYS want a VB or MR.
the contractors "Tile guy" is claiming that its not industry standard and only an option if he feels like doing it....
Ohio building code just refers to manufacture specs and ANSI

I have read over the complete post that dan referenced. and I do have page 161 of my TCNA handbook dogeared but without some more ammo to fight this contractor with, i cant get him to redo the shower now that its done. hes refusing to as USG doesn't require it.

long story short, Dana, do you happen to know where i can find that ANSI standard?

[dhagin]

You need the previous edition, 2011 ANSI A108. I'd call them and see if they have them left over.

http://webstore.ansi.org/FindStandar....#.UctPhetAj-k

or

http://www.tcnatile.com/products-and...lications.html

[Pirate]

Looking at this from a different perspective, why should USG or any other cement board manufacturer care whether a vapor barrier is used? I mean, does it have any bearing on the performance or durability of their product? No! The purpose of the product is to hold tile, that's it!

So, I think your contractor using the cement board instructions for his argument is weak. Whether it is in the code or not, best building practices and common sense would say that a vapor barrier is needed in basic shower construction. But, if the use of a vapor barrier isn't in your contract, you may not have much recourse, unless it is code for your area.

[Tiger Mountain Tile Inc]

This has been hashed out before and I also speculate as to how much recourse you would have. To really have a better idea you would need to talk to an attorney.

I think your best leg to stand on, however, is in your local building codes.

[Tesara]

Nick, if the bathroom wall is waterproofed then it has a vapor barrier by design... Two layers of vapor barrier would collect moisture between them which not a good thing...

In hot climates the moisture barrier are to installed on the outside... and in cold climates on the inside
http://continuingeducation.construct...L=51&C=201&P=5


The vapor barrier issue is a difficult to resolve in bathrooms of hot climates if the bathroom has moisture barrier on external wall as well as moisture barrier due to waterproofing on the inside... but other than that where there is waterproofing on inside should be fine as moisture barrier I would guess... I am not sure about the code in your area though..

[ncraig]

our local building code doesn't stipulate anything having to do with interior bathroom moisture barrier. as far as the shower walls, they are all interior walls inside the thermal envelope, so there is no current waterproofing on them.

heres the picture that caught my eye and started the whole arguement

[Tesara]

I misunderstood it then, sorry, so are you saying that your contractor has installed a shower without waterproofing it sufficiently...

So you don't have a liquid or membrane waterproofing on top of the CBO and the pan... as the chosen style of waterproofing... am I right

The picture could be the stage before waterproofing with liquid or membrane waterproofing on top of those elements... it is still possible that they have waterproofed it after that stage... if they haven not, it will leak...

[cx]

Originally Posted by Tesa

Nick, if the bathroom wall is waterproofed then it has a vapor barrier by design..

We need to be cautious with those terms, Tessa. Not all waterproofing membranes are vapor barriers, and we don't generally need them to be. Only when constructing steam showers are significant vapor retarders of a certain rating required.

Some method of moisture containment, and only one, is always required for any shower, though, as you are suggesting.

My opinion; worth price charged.

[ncraig]

yes, this is only a staging picture, but no waterproofing was dont to the CB after that, the pan was installed and run up the studs about 6 inches then the last of the CBO screwed down over that.

Take the pan photo with a grain of salt, i have already made them take it out and redo it, there was no slope at all to the drain. its just attached to show the CBO fully installed