Replies

1. 
   EricPaulson | Mar 24, 2007 07:23pm | #1

   Never actually have used kerdi (disclaimer)

   IF I were, I think I would use Denshield.

   Easy as Sheetrock, and just a wee bit more suitable for the application.

   [email protected]

    

    

    

    

1. 
   andybuildz | Mar 24, 2007 07:57pm | #2

   Easy as Sheetrock, and just a wee bit more suitable for the application<<
   Its a bit more expensive so why is it "more" suitable for Kerdi?

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

1. 
   EricPaulson | Mar 24, 2007 08:52pm | #3

   The application in this case being it's intended use and the eviroment in which it is installed.

   Damp location.

   Yeah, I know you will respond with all the merits of Kerdi, but a bathroom is a damp location.

   Denshield imo is a bit more rigid than SR and so imo again, makes it a bit more suitable as a substrate for tile or stone.

   I simply would not feel comfortable using sheetrock in this situation. I have talked to several people who have used Kerdi over SR and although they were confident, it was less than 100%.

   So, that my opinion, not lab tested data. So lets wait for some more opinions.[email protected]

    

    

    

    

1. 
   stevent1 | Mar 24, 2007 10:07pm | #4

   Eric,

   I too am a Kerdi convert. They claim it is 100% water proof with proper installation.

   I think the Tile Institute has a cardboard box lined with Kerdi that was done years ago. They add water because of evaporation.

   One could argue that penetrations for shower valves, shower stems, body sprays, etc break the waterproof enevelope. That would be true with any substrate.

   Chuck Slive, work, build, ...better with wood

1. 
   andybuildz | Mar 24, 2007 10:26pm | #5

   They claim it is 100% water proof with proper installation.<<

   When I did this current shower project I took a scrap of kerdi that I wiped my trowel with excess thinset on and I wrapped it around a small chunk of drywall.

   I let it dry overnight and then threw it in my bucket of water I was using to clean my knives. I forgot about my little experiment untill I dumped the water out and saw my lil' chunker O' Kerdi on rock.

   I sliced it open with my rock knife and the rock was dry as a bone....hence my question here as to why would anyone spend the time and money using a CBU behind kerdi. One of the reasons I like Kerdi is cuz I don't have to F with stinkin' CBU's...lol. Your answer was decent I guess re: moisture getting in behind the faucets but still...is it really worth it?

   Oh yeh...I also did an experiment w/ "luan" and kerdi. After I roughed up the 1/8" luan with some 36G sandpaper I thinset Kerdi on it and it held real well in spite of the luan recommendations of not using it under thinset or water.

   Here's a shot of the footstool I bent two layers of 1/8" luan around then Kerdi'd.

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

   Edited 3/24/2007 3:29 pm ET by andybuildz

2. 
   andybuildz | Mar 24, 2007 10:33pm | #6

   Before I kerdi'd and ply'd

   View Image

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

3. 
   stevent1 | Mar 24, 2007 10:48pm | #7

   Andy,

   Looks good in there. Is this shower near your sleigh tub?

   I remember the plywood 'door skin' pic from your thread at http://www.johnbridge.com

   They were telling you no way because of delamination. I am glad you went with your plan. Water will never pool on the verticle bench front.

   Chuck Slive, work, build, ...better with wood

4. 
   andybuildz | Mar 24, 2007 10:54pm | #8

   They were telling you no way because of delamination.<<<Thanks..and yeh...they were saying that to me. Was really jammin' my head too cuz the reason I went w/Luan in the first place on the footstool was because I read it in John's E-book on Kerdi. HE said you can use 1/8" "door skins". Some mixed messages in there but everythings cool....and dry :)
   so far...lol

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

5. 
   stevent1 | Mar 24, 2007 11:06pm | #9

   I have the e-book as well. I have a thread there called "No curb walk-in shower"

   They seem to be slow in answering. I asked for tips on grouting. Got nothing. We need a Rez over there.

   Chuck S

   live, work, build, ...better with wood

   Edited 3/24/2007 4:13 pm ET by stevent1

6. 
   andybuildz | Mar 24, 2007 11:13pm | #10

   I asked for tips on grouting.<<<
   SpectraLock is awesome grout!! On most things...not everything.

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

2. 
   andybuildz | Mar 25, 2007 05:07am | #15

   I FINALLYYYYYY got a GREAT answer to my question from David (Meiland.
   Its the answer I was looking for! Surprised it took so long.
   I like that he's specific...about why "CEMENT" boards are the best.
   Hope he doesn't mind me sharing it with you guys."In addition to what DG says, I can't understand trusting your tile installation to the bond between the drywall core and face paper. I can rip that apart with my hands. I cannot rip the mesh fabric out of a piece of Durock. Besides, CBU is designed specifically as a bonding surface for cement mortars like thinset and sheetrock is not. If I had to demo a shower I would much rather demo one made with sheetrock than with CBU screwed to the studs. The CBU takes marginally more time to install in a typcal shower stall, and costs more, but so what?I find Hardi slightly less pleasing than Durock, mainly because screws near the edges or corners can cause the board to just fray apart like cardboard. I will use the 1/4" on floors but for anything else I get Durock.

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

2. 
   vintage1 | Mar 24, 2007 11:32pm | #11

   Andy,

   It may be overkill to have both kerdi and durock in the same application.  but I would view it as belt and suspenders. 

   I really like the ease of installing DW rather than durock, but I have always thought of water as the universal solvent.  After all it created the grand canyon, among others.  Don't you want all the protection you can get? 

   Proper installation, and I trust kerdi, but what about the one little area that didn't get sealed quite right?

   BTW I have seen your pics in various threads and really nice work.

    

1. 
   andybuildz | Mar 24, 2007 11:46pm | #12

   Thanks
   I hear what you're saying and it's not like I haven't thought the same thing myself but playing devils advocate here...The shower I just did for instance. I plugged the drain up and I filled it with water right to the brim and left it most of the day. The floor under the shower is totally open...I saw not one drop leak out. Course I haven't had the shower on yet...I only filled the pan after I kerdi'd and before I tiled.
   I guess thinking about bidding jobs and how expense this all is to begin with...how much is the cutomer supposed to care? I mean we sell Kerdi and "waterPROOF" so what does that say when I have to say, "but just in case" and yer gonna have to pay yet even more. You know what I mean? Its one thing to do it for myself but when youre trying to sell a job....
   HEre's a shot of the underneath...still open...totally visable!

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM                                   

    

1. 
   vintage1 | Mar 25, 2007 12:19am | #13

   Andy,

   You have installed the stuff and have been able to water test it to make sure it is leak proof.  I guess the belt and suspenders comes into play if you don't have that option, such as finished floor below, or just my paranoia.   

   Someone's tag line here is (paraphrase) "never enough money to do it right the first time, but always enough to redo it".  When it comes to water, I want the extra insurance.  I think of DW turning to mush and then tile spalling off due to some small seam breach.

   Sometimes it is the unconventional practice/product that takes time to gain acceptance.  I still like the concept though, DW and kerdi. Faster install and more user friendly. 

1. 
   andybuildz | Mar 25, 2007 12:42am | #14

   Actually...I think it was in John's Kerdi book where he suggests filling the pan before you tile it and mark the waterline...leave for a few hours and come back and check the line later so it really doesn't have to be open from below...but I still hear what youre saying.

    

    

    

   http://WWW.CLIFFORDRENOVATIONS.COM