We used Hydroban over our Hardibacker cement board before tiling--a brush-on/roll-on waterproofing membrane from Laticrete. DH said it was very easy to apply.

You need either some sort of waterproofing either behind or on top of the backerboard. The backerboard will not be harmed by water, but water can pass through to the studs without protection. Also, tile and grout are not your waterproof barrier either.

Can you report about which products he's using; I mean which waterproofing product you're referring to? It's possible he's not done; that the "tape and waterproofing" you mention is really tape and mortar. If so, it's possible he'll waterproof the whole thing tomorrow. If he doesn't, I'd suggest stopping work and contacting the GC. For a link, the best thing to do is find out which prodcuts are being used and go to the websites of those manufacturers.

Sorry, forgot to make this clear - if there's no membrane, (tar paper or plastic), against the studs behind the wall board, he should be using a waterproofing membrane of some sort over the wall board. That'd be something like Kerdi, Hydro Ban, etc. If at this point he plans to simply tile over the wallboard, without first applying a waterproofing membrane, call the GC and stop the work.

This is essentially what teriks said.

Bill - There was no membrane behind the Fiberock. And the tile setters were not planning on waterproofing the entire walls. The GC is aware of this and the proposed solution was for us (me and my husband) to waterproof the entire walls if that is what we want done. I was looking for the code that requires the waterproofing. What I have found so far is UPC 417.4.1 which requires the walls to be waterproofed up to 6 ft.

Perhaps you could suggest to the GC that if he is unable/unwilling to hire a tile setter who actually knows how to do his job, you should not be expected to pay a premium for their work. Waterproofing is part of installing a shower. Period. Your tile setters should do it for no additional charge. You are not making a change order - you are simply expecting them to do their job properly. If they are incompetent in shower construction, they are likely incompetent at setting tile.

Actually, the use of a vapor barrier (the plastic behind the CBU) is his job. Waterproofing the shower is NOT his job, unless it's specifically included in the contract, or it's a steam shower. Just a clarification, because obviously either way, he's still building it the way he should.

Sorry - I was using waterproofing and vapor barrier interchangeably - won't make that mistake again.

Your tile setter may either remove the Fiberock, install the plastic vapor barrier and re-install the Fiberock OR apply waterproofing on top of it. Since he screwed it up, leave him those choices to fix it. Either way, it is not YOUR job to fix his mistake.

Alice - I agree, that is what should happen. Unfortunately, the tile subcontractor does not believe that not installing a vapor barrier IS a mistake. And I don't have anything that I can show him that will convince him it is a mistake.

Are you using a permit for this work? Maybe your city inspection department can provide you with proof.

LOL - I looked at the Tile Council of America's site and it looks like they're more interested in "CYA" than anything else. Typical professional organisation.

Yes there is a permit, it is new construction. But, doubtful that the inspector can help, we are in NC where the shower doesn't even have to have a pre-slope.

Here's something - not as authoritative as you want but it does discuss the UPC, Uniform Plumbing Code, and pre-slope.

http://www.noblecompany.com/LinkClick.aspx?fileticket=yfvL6lOjCPk%3D&tabid=71&mid=431

Ok, try "Rules for concrete backerboard IRC-702.4.1, 702.4.2 & UPC 807.1.3"

found it in this post reply by lazypup.

http://ths.gardenweb.com/forums/load/bath/msg1001473229573.html

I'm not sure I understand what you are saying. Do you mean he should have used a vapor barrier behind the Fiberock?

yes.

Is this in a code somewhere? It is hard to find the codes on-line without paying for them.

yes. As well as in the TCNA Handbook, it will also be found in the ANSI standards (American National Standards Institute-- the book that governs ALL phases of building). It'll be found somewhere either in ANSI 108 or ANSI 118, not sure which one, but if you can't find someone local to look it up for you, I'll dig and find the exact spec.

And since he didn't use a vapor barrier, is the only solution now to apply the liquid waterproofing?

Either that, or take the fiberrock back down and put up the vapor barrier.
Oh, and does UPC 417.4.1 not apply?

Not sure what 417.4.1 is. As for Bill's link to Noble Company and preslope codes, that's 412.8 in the UPC code.

The section of the UPC that talks about the pre-slope is NOT included in the NC building code. Some counties have added it in to their code, but not in our county. We already asked the building inspector about that.

We do now have a pre-slope because I said I wanted one. It meant the tile setter had to take out the shower liner installed by the plumber and start over. This meant taking down the bottom part of the already installed Fiberock. The tile subcontractor will not reuse those sheets of Fiberock because they will have too many holes in them. So, taking down the Fiberock, putting up the vapor barrier, and reinstalling that same Fiberock is not an option.

Bill - I think it is ANSI 118.10, but I can find the verbiage on line, so if you have it, that would be great.

Preslope codes will ALSO be found in ASNI 108 or 118.