# Preparing to install Kerdi on bathtub surround



## angus242 (May 1, 2008)

2 quick things:
1) You need a myspace account to see your pics.
2) I'm not sure about Kerdi over DensShield. DensShield is already a waterproof material. Typically if you're using it, I would suggest RedGard for the seams and screw holes and then you can tile.
Kerdi + DensShield equates to a double moisture barrier and I'm not sure what the ramifications of it are. Perhaps you should call Schluter to see what they say about it.


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## DIY-Renovator (Jul 6, 2008)

Ha ha ... sorry about the myspace thing, I wasn't thinking that people would not be able to access them. Maybe I can upload some of my pics here on this site (I am fairly new to this site as well).

Plus I will send the Schulter people a message to see what they say about kerdi on Denshield. But I am under the assumption that it would work since Kerdi is supposed to world on many CBUs, even drywall.


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## DIY-Renovator (Jul 6, 2008)

I have added these three pictures to my profile page on this site found here:

http://www.diychatroom.com/album.php?albumid=79


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## angus242 (May 1, 2008)

DIY-Renovator said:


> Ha ha ... sorry about the myspace thing, I wasn't thinking that people would not be able to access them. Maybe I can upload some of my pics here on this site (I am fairly new to this site as well).
> 
> Plus I will send the Schulter people a message to see what they say about kerdi on Denshield. But I am under the assumption that it would work since Kerdi is supposed to world on many CBUs, even drywall.


I'm not saying it won't work. I'm saying it might not be a good idea. The materials you speak of are not moisture barriers. DensShield is. So is Kerdi. You are not supposed to use a double moisture barrier. 

Since this question has come up more than once, I have already called my Schluter rep and am waiting for his reply. I'll post their recommendations.
If you have the time, I'd wait for the answer before continuing. I personally would not use the procedure you described. Since the DensShield is already up, I'd tape the seams and waterproof them and the screw holes with RedGard.

Waiting on Schluter...:whistling2:


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## DIY-Renovator (Jul 6, 2008)

Thanks for the replies and yes I have been swapping the idea of using Kerdi versus RedGuard for some time now and have not commited to using either product yet. Plus I am in no rush since I am sure I am a week away from waterproofing my shower surround.

I guess I was leaning towards using Kerdi since I wanted to extend my tiling around 6" on one side of my tub that is on top of some moisture resistent drywall and not on the Denshield. I would guess that RedGuard would also work on this moisture resistent drywall?

Question:

what makes putting Kerdi (a moisture barrier) over Denshield (a mositure barrier) any different than putting Kerdi over something like Durorock (a moisture barrier CBU) or Hardiboard (another moisture barrier CBU). Enquiring minds want to know. 

PS: I have to run away from my computer for several hours now, so I am in no rush to address all of this stuff this very minute.


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## angus242 (May 1, 2008)

DIY-Renovator said:


> Question:
> 
> what makes putting Kerdi (a moisture barrier) over Denshield (a mositure barrier) any different than putting Kerdi over something like Durorock (a moisture barrier CBU) or Hardiboard (another moisture barrier CBU). Enquiring minds want to know.


CBU (durock, hardi, etc) are NOT waterproof nor are they moisture barriers. That's why you'd put a moisture barrier like Kerdi OVER them.


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## angus242 (May 1, 2008)

*Clarification*

After talking with both Schluter and Georgia Pacific, these are the facts:

Kerdi OVER either DensShield or DensGuard IS allowable using an unmodified thinset.

DensShield/DensGuard are NOT a vapor barrier. Their claims of moisture barrier are a bit misleading. The moisture barrier part is only after the panel is tiled. 

We all know that tile and grout do not make a wall waterproof. 
Therefore, I would conclude that DensShield with tile directly over is NOT 100% waterproof. It may retard vapor penetration but that's it. If you want _waterproofing_, it's Kerdi or RedGard (or one of their competitors).

DIY-Renovator, you got thumbs up for the Kerdi :thumbup:


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## 26yrsinflooring (Jul 1, 2008)

Let me chime in here.

No problem going over the denshield use unmodified as Angus suggest.

Kerdi is the best stuff on the market. Excellent choice.

I do disagree with Angus on the redgard but other than that we seem to agree on most procedures.

I am Schluter dealer, have you got your Kerdi already?


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## DIY-Renovator (Jul 6, 2008)

Thanks for the replies and to answer 26yrsinflooring's question, no I do NOT have my Kerdi yet. But I am up in Canada and it could be a hassle buying Kerdi off of a US dealer. I may be better off looking locally (Home Depot has it but I am sure I can get a better price elsewhere).


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## 26yrsinflooring (Jul 1, 2008)

I ship to Canada stop send me a PM or just view my website it is in my profile.
I have best price in the two nations combined

I Use DHL instaed of UPS so they dont kill ya with brokers fees.
How much Kerdi do you need?

30% of my market goes north of the border!


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## DIY-Renovator (Jul 6, 2008)

Is it http://www.indianafloorsllc.com/ ?

I will have a looksee at the website later this evening. :thumbsup:


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## 26yrsinflooring (Jul 1, 2008)

That is it,stop by.


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## DIY-Renovator (Jul 6, 2008)

LOL ... looks like I need to make 20 posts before I can send someone a private message on this site and since I am relatively new here I am only 1/2 way there. I want to do a little more investigating to make sure I am comparing apples to apples, but the prices on your Kerdi do appear to look good (if I am seeing them correctly).


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## DIY-Renovator (Jul 6, 2008)

Is your Kerdi full roll the 54 sq foot version? I think I only need about 80 sq feet for this bathroom, but I also plan on doing a 2nd bathroom in the future once this one is finished. So having some left overs on this project is fine.

PS: sorry to everyone else reading this. But I have to get my posts up to send PMs. :whistling2:


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## 26yrsinflooring (Jul 1, 2008)

You can order by the sq foot, send me an email off the site, the "Contact us" link is red in the left hand menu.

I will make you deal you cannot refuse!


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## angus242 (May 1, 2008)

26yrsinflooring said:


> Kerdi is the best stuff on the market. Excellent choice.
> 
> I do disagree with Angus on the redgard but other than that we seem to agree on most procedures.


26, I _only_ suggest RedGard because some DIYers seem to be afraid of Kerdi for whatever reason. I will *ALWAYS* suggest Kerdi over RedGard. However, if someone isn't going to use Kerdi, RedGard is better than nothing.

Kerdi *IS* the way to go.


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## 26yrsinflooring (Jul 1, 2008)

I have used redgard but the warranty on it is odd: If the you do not use a film thickness guage in all your applications you can void the warranty.
I choked on that one a bit.
I only use for steps and wood outside inset tubs then I overlay it with kerdi.
Call me crazy but it better to be safe than sorry.


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## DIY-Renovator (Jul 6, 2008)

Thanks for the private message "Bud Cline". I would have replied to you via another private message but I still need to make a few more posts before I am allowed to. 

Haha ... sorry folks. :laughing:


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