# Hardibacker & wall insulation



## joecaption (Nov 30, 2011)

There is no need for an additional vapor barrier.
Still going to need to water proof the tile board before tiling.
Google "Red Guard".


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## oh'mike (Sep 18, 2009)

Joe said it---one vapor barrier is enough---

If you are going to waterproof the face of the board (I highly recommend doing that)
Then you do not want a vapor barrier on the insulation---so slash the bagged insulation before adding the backer board.


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## ron45 (Feb 25, 2014)

Is this shower going to be tiled, fiberglass, plastic, etc..?


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## goose1078 (Jan 27, 2015)

Hi, thanks all. The shower will be tiled. So get the paper Kraft faced insulation then hardibacker then red guard?


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## oh'mike (Sep 18, 2009)

Use unfaced bats or slash the paper--it is a vapor barrier.


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## goose1078 (Jan 27, 2015)

Hi, again couple more questions.. 

1. Do still need to use tape for the hardibacker sinse I will use redgard? What kind of tape. 
2. What thinset is recommended? 
3. I plan to tile to the ceiling already gutted the shower wall where about 6 feet it was Cement Board, so I am left with about 2 feet of plaster to ceiling. Should I rip these 2 feet of plaster out and use hardibacker to ceiling or can I use hardibacker up to plaster and then regard to ceiling with tile on top? 

Thx in advance, 

Frank


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## oh'mike (Sep 18, 2009)

If the Hardibacker is exactly the same thickness as the old plaster--then leave the existing material--

If not---remove the old plaster---patch the ceiling corners and do the backer all the way up---

You want to tape with 'tilers mesh'--alkali resistant tape---There are small rolls in the tile section of the home depot---or larger rolls in the drywall isle.

I suggest you use a good modified thinset (powdered)--I almost always use white--


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## goose1078 (Jan 27, 2015)

Hi, thanks for the advice above. I ended up taking it all down. Will be using wool insulation, then hardibacker and will then roll redgard for barrier. 

Qq. What if I want to build a niche and it's an outside wall. Do I just not insulate this part? 

Thx, 

Frank


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## oh'mike (Sep 18, 2009)

It will be a chilly niche---but--no insulation would be possible----

waterproof it well---


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## goose1078 (Jan 27, 2015)

hi, again. So I put the hardibacker up and built the niche. I have been reading that instead of thinset and mesh tape, I can use a water proof mesh and redgard on seems and corners. Would this work just as well as thinset and mesh before redgard? 

Thx, 

Frank


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## dennisht (Mar 22, 2015)

*basement bath*

The US Department of Energy says reflective insulation should not be used in cold or very cold climates. Besides, it's designed for attic installation in reflecting heat outward where it's used as a radiant barrier. Foil used as a vapor barrier on a basement wall will likely trap moisture behind the wall and feed mold. (Mold can grow on a concrete wall, not just wood.)
I would simply fit in XPS as tightly as you can and seal with building tape or foam around the pipes and wiring.


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