Help, Kerdi did not stick, What happened ??
Mongo, Bill ... I wish now I had not talked DH into using Kerdi on the tub surround in a rental house we are fixing up. It was supposed to be "practice" for our own remodel.
DH installed Hardi directly on the studs, with no vapor barrier. He attempted to hang the back wall by himself (I was not there). He hung the first sheet 3 times, and then the second sheet. It was not sticking so he ultimately took it all off and cleaned up the mess. Needless to say, he was not very happy. Obviously he was doing something wrong; he said it was drying out too fast. He wetted down the Hardi and used more water in the thin set.
The next day I bought another roll of Kerdi and we attempted it together. This time I used a pump-up garden sprayer to wet the Hardi and DH used the Kerdi 1/8" notched trowel and the same unmodified thin set. It was going much better; we both felt it was going to work this time. We came back the next day and, with no effort at all, the Kerdi could easily be peeled off the wall. It was only firmly attached at the top 3 inches where we primed the taping mud at the Hardi-to-drywall seam.
The unmodified thin set was mixed to the consistency of "mayonnaise" or "a milkshake" per the Kerdi tech support guy I talked with in Reno. We worked fairly quickly, and the temperature was about 77 degrees that day. The only thing I can think is we did not get enough thin set on the wall before hanging the Kerdi ... but we used the Kerdi 1/8" trowel and removed very little when we smoothed out the Kerdi. Obviously, the Hardi pulled the moisture out of the thin set because it was only attached where the Hardi was primed.
At this point neither one of us has much faith in our ability to apply the product.
Do you have any idea what went wrong?
Any suggestions on what to do now (with no moisture barrier behind the Hardi)?
It will be easy to remove the dried thin set from the Hardi - I could scrape it with my fingernail.
Thanks in advance for any advice you can give,