Hardibacker Over Drywall In Shower

highpeaks

For years I've installed 1/2 hardi over 30lb felt stapled to studs. Last week I spoke to another contractor who uses 1/2 drywall over the studs. Then laminates felt with roofing adhesive to the drywall. Then the hardibacker.

He says that is makes for a stiffer wall behind the tile. Does anyone use this technique? Any comments? What type and size screw would I use to make up the additional 1/2"?

mikeswoods

Forget that idea.

angus242

Comments? Yes. Don't do it!

Why don't you waterproof a shower with any of the multiple materials designed for that?
A very common way is to use DensArmor drywall and cover with Kerdi. Some guys use 1/2" CBU and then Kerdi.

You could use Denshield (which is a 1/2" waterproof drywall panel) and address the seams and holes with a liquid waterproofer. Laticrete, Custom and Mapei all make them.

Either method is WAY better than the goofy roofing felt way. Why use a roofing product when there are many products available that are designed for this exact situation?

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L@EConstruction

I always lay my liner then overlap a 50mil plastic up the walls. I know it sounds awful but we had it left over from a vapor barrier on a job and it works great for it. Then I cover with hardi. No problems so far. I also usually tape all my seams on my hardi. We used the kerdi(sp?) on this last job and it is nice as well.

jarvis design

1/2" concrete board, then Kerdi = waterproof. Some guys use denshield or hardi as the backer and I've talked to one contractor here that uses easy board - then kerdi (can't remember who!). Schluter kerdi can even be installed on normal drywall - afterall it is 100% waterproof, however, I tried it and went back to CBU.

Point is, if you are doing a shower or tub surround you are, in my humble opinion, not doing your customer any favors by NOT using either kerdi or, if you prefer, one of the other aformentioned liquid membranes.

And please don't tell me people won't pay extra for something as silly as waterproofing. EVERY customer of mine paid for and got a waterproof tile job (complete with epoxy grout). I can't think of one that thought that was a bad decision.

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Bud Cline

WHY pray tell?

.....and why would a stiffer wall behind the tile be necessary? What's the point?

BCConstruction

You guys would be amazed at how it's done in the UK. In all the years i have been a plumber i have never seen wall tile put on anything but Drywall and plastered plasterboard and have never seen one shower area where it has failed. tanking is always used on wet room installs though but for a normal shower or bathroom it will be directly on the drywall board with no water proofing or membrane. A coat of unibond pva is applied to seal the wall and get better tile adhesive.

R&D Tile

And, are you doing it that way also?, hope not.

If so, remove the word PRO from under your name.

BCConstruction

When we was in the UK it was really the only way it was done. Worked in thousands of houses and never see it done any other way. But over here i do it the long winded way. Like they say "When in Rome"

Mike Finley

Never seen one failure?????? That's the way every bathroom built in the 80's and 90's was done over here, and I see that set up failing at least 3 times a week or more.

The water in the UK must not be as wet as it is over here.

Bud Cline

My grandpappy used to have to stand in front of his automobile and crank a big handle in hopes that it would start the motor running. Things change. No one ever accussed anyone in the UK of being progressive anyway.

BCConstruction

It's still the way it's done to this date. Some guys do use the soundblock or multiboard but it's very few and far between. I have even seen lath and plaster walls with tile that had been on them for 40+ years and they were sound as. Had trouble getting them dam tiles of them walls. But still to this date i have yet to see a plasterboard/drywall backing fail. Im sure if not done correctly they would fail but as of yet i aint seen one with my own eyes.

Mike Finley

Okay, maybe I am misreading what you are saying. What we see here in the states from the 80s and 90s is drywall with tile over it.

Are you saying drywall with plaster over it? Or just drywall by itself?

When we have lath & plaster in a shower with tile, it's almost always lath and plaster + chicken wire and deck mud and tile.

BCConstruction

Yeah either plasterboard/drywall plastered. The lath construction really depends on age of house. 90% of lath and plaster in UK we worked on was the old skool type with horse hair inside. Some of the house we did that were 700+ years old were just cob wall construction. But still as of yet not seen one tile job fail from not using the moister resistant board. Some of these tile jobs had been in longer than i was alive.

R&D Tile

Maybe by your 5th birthday you'll start to see some failures.

jarvis design

One thing that may make a differance between tile in England and here is that English people do not shower as often or for as long as we do here. May sound funny, but, they have always been much more conservative with their water use. May explain their smelliness

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Bathrooms Built for Life.
www.JarvisDesignBuild.com
519-495-4062