vapor barrier behind a shower?

[tcianci]

Hey FTP

Get ouy your old earth science books and brush up on the conditions and science behind condesnsation. Your explanation is *** backwards. The truth of the matter is the tile and the grout is the moisture barrier and ANY system behind it will fail if the tile and grout is not maintained. The last situation you want is to have water get behind a tile job, especially with todays materials. All the new materials will accomplish is the ability to hold a failed tile job together for a lot longer ultimately elevating the severity of the damage that will be observed when the job is ripped out.

 

[Busted_Knuckles]

Just want to let you know that Kerdi or Schulter membrane is EXPENSIVE. And you want to make sure you read read read and follow the directions to a T. You don't want to waste any of it or put it up incorrectly. One of the things I purchased was a low speed drill from Harbor freight to mix the thinset before applying. You don't want any air bubbles in your thinset when your adhering this stuff to sheet rock or durarock.

Great info, thanks again for the tile forum link, I see that John, who has the tile website, has an e-book on applying the membrane, I think Im going to buy it. Not sure Im real concerned on the price, if the stuff works.

 

[Bevis]

You may want to look into the Kerdi shower system. It has many waterproofing components for showers. It will at least give you some ideas.

http://www.schluter.com/5288.aspx

Great stuff...just finished two showers for my parents and soon starting mine, using the kerdi. It was very easy to work with and went fast.

 

[e-tek]

Well I don't know if Frank knows his *** from a hole in the ground - but he sure seems to know moisture-barrier systems!!!!

We did our upstairs bath last year and spent a LOT of time on the research. We went with regular pink insulation, 6 mil plastic/acoustical sealer (not staples) as vapour barrier, cement backerboard, then the Schluter system, which consisits of an expanded polystyrene shower pan and curb and kerdi membrane over everything, embedded in thinset, then tile on top, grouted and sealed with a grout and tile sealer.

As mentioned above, the kerdi membrane serves 2 key purposes: it is a moisture impermable membrane that no nails or screws are put through and it servesas a "uncoupling membrane", which means if the structure moves (house expands/contracts), that is not transfered to the tile and grout, so they don't crack as easily.

I'm about to do our master/main bath in the spring and have kept up on my research (hours of DIY network helps!!) and will be doing it "nearly" the same way, meaning that we're using a shower pan instead of a tiled floor. The key here is to make sure the kerdi membrane comes over the lip of the shower pan so any mositure going through the grout stays inside the shower system.

One thing they do on Holmes and DIY is to use kerdi on the bathroom (and even kitchen) floors. I think that's overkill, but likely it's not. Taking into account Franks point of spendng more to do it right the first time, it's likely the right way to do it.