Return to the Bathrooms Forum | Post a Follow-Up

 o
Wrong Adhesive/Thinset over Kerdi? Panic mode

Posted by gbsim (My Page) on
Wed, Jun 11, 08 at 9:40

Just when my stomach knots were untied last night, I discovered what I hope is not a huge problem.
The porcelain tile on the back wall and floor of the Kerdi shower are up (bullnose was backordered and will be in tomorrow, so only those two surfaces were done). According to the bags and tub and what I saw them using looks as though a premixed adhesive (Acrylpro) was used on the walls and then modified polyblend thinset on the floor.
AFter looking at a post here and then going to the Schluter/Kerdi website, I see that it should be unmodified only. What do I tell the tiler when he comes tomorrow? Does the work need to be taken down? Can it be taken down? Is the Kerdi and/or my tiles ruined? Help!


Follow-Up Postings:

 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Does the work need to be taken down?

ABSOLUTELY!! NO MASTIC IN A WET AREA, and especially over a waterproof membrane like Kerdi!! That'll hold the moisture in where it can attack the mastic and reimulsify it. It won't be long before the only thing holding up the tile is the grout!!

I don't mind using a modified thinset over the Kerdi. My preference is for the non-sag thinsets, but it MUST be a portland cement based powdered thinset. It CAN NOT be mastic, and shouldn't be in a wet area, anyway, REGARDLESS of the Kerdi!! Pull it down, NOW, while you have a chance to save the tile and the Kerdi. I'd be willing to bet a weeks pay the mastic from yesterday's still soft.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

The floor should be okay, I also have no problem using a lightly modified thinset with Kerdi. For warranty purposes, I even have a letter from Schluter's tech department giving me the go-ahead.

The walls? Your tile guy will probably put up a fight, but all you have to do is ask him to show you where Acrylpro is an approved adhesive over Kerdi.

Like Bill wrote, Acrylpro needs air to cure, and when sandwiched between tile and Kerdi it's sort of suffering from asphyxia, so it's probably still soft.

Mongo


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Thanks Bill and Mongo. I called Kerdi after I posted this AM and they gave me the name of the Kerdi tech rep for our area who was VERY nice.
The Kerdi technical rep said to take down the mastic 6x6 on the back wall and that the floor esp since it was 2x2 tile would be okay. Then I got on here and saw that you two agreed. The Kerdi rep asked to speak to the installer, was very nice and said that he was glad that the installer was using the product, but that he wanted to educate him on how to use it correctly.

I then hitched up my overalls, pulled my cloak around me, tightened my helmet and called the tile installer. (Woman homeowner calling to tell you what to do.... already at a disadvantage!). He was nice, but said that this isn't his first Kerdi shower and this is the way he has been doing them and that the other showers were all fine. We sort of had a brief stalemate on the phone. Then I asked if he would be willing to talk to the Kerdi tech rep and he said yes if it would make me feel better. I gave him the phone number. And thats where we are now.

I'm only going to be happy if the wall comes down as everybody in the know has recommended, but am I wrong in being willing to give him a chance to make it right and do it according to the Kerdi recommendations?
Also.... is there a time element here? Do I need to be pushing him to get the tiles down asap or just wait a day or so until he gets the bullnose and comes back to do the rest of the job.
He did a nice job on the pattern....
As pros, Bill and Mongo what do you think I should do? Take the tile off myself or wait and see what happens... I might not hear back from him for another day.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

but am I wrong in being willing to give him a chance to make it right and do it according to the Kerdi recommendations?

Not at all. In fact, legally speaking, you HAVE to give him atleast one chance to make it right, anyway. If after being "enlightened", he still screws it up, then I'd question the intelligence behind letting him try again.

is there a time element here?

yes and no. Although they'll come down easier the sooner they're pulled down, this is one of the reasons why mastic shouldn't be used here. As Mongo alluded to, you have the kerdi waterproof barrier on one side, and the porcelain waterproof (for all intents and purposes) tile on the other. The mastic has no way to dry in any reasonable length of time, so if he were to wait another day, I don't think it would make much difference.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

" I'd be willing to bet a weeks pay the mastic from yesterday's still soft."

I was hoping that Bill was making enough to let me retire, but I won't be getting his week's pay. I pulled off some tiles and yes, except for the grout lines and a thin rim around each tile they are as wet as they were when put up.

I called a tile contractor I found through the NTCA website about 75 miles away who does Kerdi and talked to them. If they take over the job, I think they're wanting to just start ALL over in order to warranty their work. The new people raised some other questions about the original install and job too.

He's a really nice guy, but unfortunately we've lost our confidence in the original installer plus see the photos and give opinions. I think that we'll just keep the tile, pay for the job not finished and start over. Otherwise, I'd be such a wreck looking over his shoulder while laying, grouting etc that I'd be insane.

The good news is that it was only one wall and the tiles are cleaning up beautifully... a minute with the hose and the scrubbrush and you'd never know they were on the wall. So I'll "only" lose the floor tiles and the 3/4 payment that we've already done if we start over.

Sigh.... (When giving opinions on the tile be kind as it's my design and I LOVE the tile I picked!!)

http://s282.photobucket.com/albums/kk247/gsimcoe/?action=view¤t=100_3305.jpg
http://s282.photobucket.com/albums/kk247/gsimcoe/?action=view¤t=100_3306.jpg
http://s282.photobucket.com/albums/kk247/gsimcoe/?action=view¤t=100_3307.jpg
http://s282.photobucket.com/albums/kk247/gsimcoe/?action=view¤t=100_3311.jpg


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

"The good news is that it was only one wall and the tiles are cleaning up beautifully... a minute with the hose and the scrubbrush and you'd never know they were on the wall."

And that is just the reason why that you don't want to use a water soluble adhesive in a wet area like a shower!

You're doing the right thing.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Makes me wonder what he put up the kerdi with.
Casey


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Here are your pictures

And I have a question - What did the installer use to adhere the Kerdi to the walls?

Overall it looks nice
floor meets back wall

floor meets back wall over a 16
no spacers on the gray so it was off when you look close


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

A little rough looking in spots.

Your installer should be thanking you in the end, as this little bit of education should make him a better technician later on.

If he finishes your installation, instead of a cash tip perhaps instead you should educate him about tile spikes.

And if his birthday is coming up, he might enjoy a copy of the TCNA manual.

Mongo


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

He's a nice guy and we felt bad about letting him go, but it was a relief in the end. He was acting as GC for the remodel too and there have been a few other things that haven't been up to snuff and we've had to redo personally. This was the last straw (and a big one!) and we decided to finish the job on our own and sub out the tile and remaining plumbing work that we can't do ourselves to people of our choice. We've had small issues with every phase so far and so it wasn't likely to get any better... there were just too many corners being cut.

I'll be talking to the tile contractor I found through NTCA and the Kerdi folks and we'll see what happens next.
We acted as GC when we built the place 23 years ago, but this time wanted somebody to do it for us and let us sit back and watch the action.... wrong! I'm the type that needs to know that it's done right and will insist that it is redone until it is.

Off to have my coffee before pulling tiles!


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Thanks Terriks for posting the pictures from what is visible anyway it appears that the actual Kerdi fabric was put up with thinset. But whether the drain and overlaps, niche etc were done right I don't know. I thought I could just sit back and stay out of it so wasn't watching what happened with the initial work.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Reminds me of several installers shopping at the same time as I was in Lowes and HomeDepot who bragged to me about not doing some of the things required by manufacturers. Or, the Lowes tile sales person who recommended using mastic instead of thinset for installing tile on the shower ceiling. That is not the way to earn trust to use their services/products.


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

Can you use flex bond from home depot to put up kerdi menbrance?"


 o
RE: Wrong Adhesive/Thinset over Kerdi? Panic mode

If you want to follow Schluter's guidelines, then you'll usually use an unmodified thinset to install and tile over Kerdi.

If you want to go off on your own and use a modified thinset, then at most use a lightly modified thinset like VersaBond.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Bathrooms Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here