# Membrane over Durarock for Tub Surround



## mtplus (Jun 22, 2006)

Is it customary to put a waterproofing membrane over Durarock ( or other cement board) to guard against leaks at the seams and nails?


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## doubleaction (Oct 22, 2005)

I've always heard of using thin set on the seams. But im just a dumb roofer that does alittle remodeling here and there. Just my .02


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## mtplus (Jun 22, 2006)

I would indeed put thinset on the seams. However I am still wondering whether it is a good idea to add a membrane over the cement board.


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## doubleaction (Oct 22, 2005)

Sorry like i said im just a dumb roofer


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## A+Carpenter (Apr 19, 2005)

mtplus said:


> Is it customary to put a waterproofing membrane over Durarock ( or other cement board) to guard against leaks at the seams and nails?


Depends on how many problems you want down the road. Each product has certain products that help it withstand the duration. 

The membrane I have used on several small projects and I love it. :thumbsup: 


Good thread


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## mtplus (Jun 22, 2006)

What membrane did you use?


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## Mike Finley (Apr 28, 2004)

No membrane over durrock on bath or shower walls.

Moisture barrier *behind *the durrock.

Or switch to DensShield with build in moisture barrier.

Joints on durrock are supposed to be left with 1/16 gap between them and mesh taped and thinsetted over. When I did use durrock back in the stone ages :whistling I would slip a couple of nails between the sheets of it while going up the wall for correct spacing.


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## bob the builder (Oct 6, 2005)

A+Carpenter said:


> Depends on how many problems you want down the road. Each product has certain products that help it withstand the duration.
> 
> The membrane I have used on several small projects and I love it. :thumbsup:
> 
> ...


I'm also curious specifically what membrane you used???

Bob


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## mtplus (Jun 22, 2006)

*Membrane over Durrock*

Mike,
I assumed from your message that you have transitioned to DenShield. Is that correct? Are there any special issues with DensShield that you know about (I have read the GP website about how not to use Denshield)?:

Thanks,
Robert


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## ApgarNJ (Apr 16, 2006)

I use the hardie backer behind tile and don't do anything over top of that. i use mesh tape and thinset all the joints and corners. no vabor barrier behind it either. if it's being tiled and the grout is sealed, there shouldn't ever be moisture behind the hardibacker.


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## Gordo (Feb 21, 2006)

mtplus said:


> Is it customary to put a waterproofing membrane over Durarock ( or other cement board) to guard against leaks at the seams and nails?


Redgard, a paint on membrane(waterproofer). There are also other paint on membranes so consult your local tile shop.


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## tzzzz216 (Dec 25, 2005)

I've used duraock many of times and never had a problem with it, all i did was mudded and tape the joints then tile and grout it .




Try to send these jobs overseas!!


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## Mike Finley (Apr 28, 2004)

mtplus said:


> Mike,
> I assumed from your message that you have transitioned to DenShield. Is that correct? Are there any special issues with DensShield that you know about (I have read the GP website about how not to use Denshield)?:
> 
> Thanks,
> Robert


I am very new to it, just starting using it on the last couple of jobs, but so far I am liking what I am seeing. It is certainly much more 'employee' friendly than Hardi, which is what I need.


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## SteveG91 (Jul 5, 2006)

Some do, some don't. Go over to JohnBridge.com, find the Tile Advice Forums, then the Advice Forum, Search for Redguard.
That's a very good starting point.

Steve


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## mtplus (Jun 22, 2006)

Mike Finley said:


> No membrane over durrock on bath or shower walls.
> 
> Moisture barrier *behind *the durrock.
> 
> ...


Mike,

1. What is the purpose of the 1/16 gap between panels? On the surface that would seem to increase the possibility of moisture getting past the Durrock.

2. What membrane did you use behind the Durrock? CPE?

3. One problem that I have read about DensShield is that once the moisture barrier is breached ( as in having to replace a tile because the barrier will come off with the tile) you have a problem. DOes this concern you?

I guess the bottom line is, if you were installing a backer board in YOUR house, would you use Durrock, Hardibacker, DensShield, Wedi board or something else?


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## Gordo (Feb 21, 2006)

Durock is the only way to go. Put some Denshield outside in the elements along with Durock.......then wait a year. You will understand.

Who cares about employee friendly? I think the people having the problem with Durock are not using the proper saw blade or are tired of stabbing thier fingers with the drill drive.


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## Mike Finley (Apr 28, 2004)

> 1. What is the purpose of the 1/16 gap between panels? On the surface that would seem to increase the possibility of moisture getting past the Durrock.


As I recall it was for expansion or some crap, but it was so long ago I can't even remember. You were supposed to tape and thinset the seams.




> 2. What membrane did you use behind the Durrock? CPE?


Roofing felt.



> 3. One problem that I have read about DensShield is that once the moisture barrier is breached ( as in having to replace a tile because the barrier will come off with the tile) you have a problem. DOes this concern you?


As I recall they recomend you to thinset over any breaches.


> I guess the bottom line is, if you were installing a backer board in YOUR house, would you use Durrock, Hardibacker, DensShield, Wedi board or something else?


DenShield on walls, 1/4 hardi for the floors.

I should add too in regard to all this stuff about moisture barriers. I'm tearing out old tile surrounds on showers and tubs on average about 4-5 a month and I have yet to see any water damage other than areas where the tile and sheet rock it has been layed on has been damaged or rotted from direct water penetration from splashes or the shower heads. No moisture barriers are ever there and there is no water damage or issues anywhere other than around these areas, no water damage anywhere else in the interior walls. I would see it for certain because we tear out all the old drywall and replace it with DenShield so it is exposed for easy inspection.

Now we are an extremely dry climate so maybe that is part of it. Do you guys see the same thing or something different?


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## Mike Finley (Apr 28, 2004)

Gordo said:


> Who cares about employee friendly? cry:


Gordo I have to care about it because it's my butt and my profits on the line. Installing Durock is akin to running around in a room with orbital sanders taped all over your body. The stuff gets near anything (like an expensive cabinet and it's toast).

Ever see somebody putting Durrock on floor and trying to get it place and scrape the hell out of the wall, the wood work and everything else? I have, cause I've even done it!

My plans don't involve doing the work myself forever so I have to look for systems that minimize damages and maintain profits as long as we don't compromise the finished product.


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## R&D Tile (Apr 5, 2005)

Boy, this is one confusing thread. 



> Durock is the only way to go. Put some Denshield outside in the elements along with Durock.......then wait a year. You will understand.


 Nonsense, have a piece of Denshield outside right now for over 5 years in every weather condition there is, it looks and feels the same as it did 5 years ago.:thumbup:

Would never touch Wonderboard or Durock again, those small pieces get everywhere and scratch everything, too heavy also.:no: 

I use Hardie and Denshield, Hardie in showers with mud floors, or membranes over Hardie or drywall.

As for what type of barriers to use and where, here goes,

4 or 6 mill poly or 15lb. roofing felt over the studs and behind all CBUs, except Densheild, if using a waterproofing membrane over your CBU, do not install a vapor barrier over the studs.


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## nadonailer (Nov 15, 2005)

FWIW - I use 6 mil poly on the studs, Hardie - mesh taped and mudded with the viscous membrane on any seats, etc..
Although I have torn out many old walls and not found any moisture either. I suspect the way I do it is overkill, but better safe than sorry. Its a little bit extra time and materials, but I know none of mine are ever gonna leak through.....
PS - Grout is not waterproof, it's much like stucco and should be expected to pass some moisture through it.....


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## Double-A (Jul 3, 2006)

nadonailer said:


> .....
> PS - Grout is not waterproof, it's much like stucco and should be expected to pass some moisture through it.....


Amen and amen.


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## JohnFRWhipple (Oct 20, 2009)

I believe here in Vancouver a free standing tub needs waterproofing 16" - 18" above the height of the tub. This rule is kind of a weird one because what happens if the walls are to be painted?

This corner will receive a few slabs but just to be safe I put up two coats of Mapei's Aqua Defence.

John Whipple
By Any Design Ltd.
Waterproofing and Linear Drain Installations
North Vancouver
[email protected]


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## JohnFRWhipple (Oct 20, 2009)

I googled "How to waterproof a tub surround" and look at this advice online.

*"Once the tiles are in place on a tub surround, the next step is to waterproof the area to ensure water does not seep behind the tub. Waterproofing is critical to the longevity of your new tub surround and can not be overlooked."* * Source

Read more: How to Waterproof a Tiled Tub Surround | eHow.com http://www.ehow.com/how_5689666_waterproof-tiled-tub-surround.html#ixzz1bWjihY3e

http://www.ehow.com/how_5689666_waterproof-tiled-tub-surround.html

I wonder how many tub surrounds Melissa has done... :whistling

So who is Melissa. "Melissa Kelly is a freelance writer from Indianapolis who focuses on scientific and medical topics. Kelly attended Marian College where she obtained a Bachelor of Science degree in chemistry. Recently, she completed her Master's in business communications & project management." * Source

So now EHow is paying for articles. This has been going on for over a year. Loads and loads of garbage information all online for "Free".

Know your source of information before proceeding on any building project.

JW


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