Green board in a shower?

[chas22]

I have a question. I used Hardibacker under tile for a tub encloser, but while watching HGTV they used greenboard on the wall studs then Hardibacker then the tile. My question, is this the proper way to do this? I thought if the moisture would happen to get through the Hardibacker that it would cause mold to grow between it and the greenboard with no way to remove it.

[ddmoit]

There is no reason to use greenboard under Hardiebacker.

I trust that you put a moisture barrier behind your Hardiebacker.

[chas22]

I used 15lb roofing felt against the studs then installed the hardibacker. This is correct I hope.

[Tool Guy - Kg]

That method will work. Felt on the studs and brought over the front of the tub flange has been used in many successful installs.

The Hardi over drywall isn't wrong, it just isn't necessary in many cases. Sometimes, someone wants the look of a mud job so they build on top of the drywall and use mud cap pieces. The moisture barrier in this particular installation would go over the drywall before the Hardi was hung.

[Davestone]

You're good.

[Dobri]

Please don't beleive the TV specially HGTV. I watched today the show "Save my Bath" on HGTV. The "contractor" that works with the designer was installing tile over 1/4 hardie in bath tub shower enclosure without moistre barrier and without taping the seams with CBU tape and thin set. I was shocked and this is on national tv.

[jdm]

Kurt --

You are good. I saw the episode and they stated that they used the greenboard to build out the tile so it could be finished with mud caps (they didn't call them mud caps, however).


Dobri --

James Hardie says that 1/4" Hardibacker could be used for walls over studs 16" o.c. Personally, I would spring for the 1/2" stuff. The lack of a moisture barrier and taping is another story. (James Hardie's instructions refer you to your local code on the question of vapor barriers.) Many of the TV shows show CBU (any and all brands) used on floors without thinset bedding and without taping the joints. I've pointed this out so many times that one friend just groans every time I do it.

[Dobri]

I know what Hardie says, but everyone who worked with hardie knows how sturdy 1/4 inch is. I mean come on... 1/4 on walls and you have to have moistre barrier on walls behind CBU. See the thread "Fun with bathtub/shower re-tiling..." post #5. if you don't want to have mold on the bottom and behind walls you will use it.

[gueuzeman]

If you need to build out the walls for mud cap, use strips of plywood on the studs and then proceed as a normal install. Why put a gypboard sponge behind your tile wall?

HGTV- the red flags go up when potential customers tell me they watch it all the time.

Bang head smiley and/or other frustration emoticon here-

gueuze