Can I Use Any Thin Set With Kerdi? The ICC-ES Evaluation Report On Kerdi Says You Can

[johnfrwhipple]

...Over drywall, unprimed, no mud, assuming you wait the 24-hours they recommend when doing a flood test, the sheet is adhered pretty well and probably better than with a modified. Yes, a modified has better initial tack and ultimate strength, but if it isn't embedded into the fleece well, it could easily end up being weaker than a proper dryset installed properly. And, where you're talking about TONS of pull required to break the bond with either dryset or modified, why not use a dryset? ...

Jim you don't sound very sure in your post.

"Pretty Well" "Probably better" "Could Easliy"

The problem with your claims is that for one you still have not recommended a primer for all those jobs that do get drywall compound and to date Schluter is yet to return my email.

The second big one is you have no solid test data to draw from. Who tests these products? You mention the ICC but they actually do not test the product.

You and I are just bumping heads here. We need data. We need pictures. We need a "Mad Lab Test".

I have a bunch of Laticrete 317 Floor and Wall thin-set at home and the "Ad-mix" to make it modified. I will install four samples today on my own home's drywall in my office. The office is unfinished and I have a wack of drywall here. I might even do six samples.

Sample One: Kerdi over dusty drywall no drywall compound - set with Laticrete 317 no "Ad-Mix"
Sample Two: Kerdi over clean, lightly sponged drywall (sponge with clean water) - set with Laticrete 317 no "Ad-Mix"
Sample Three: Kerdi over primed drywall - primed with Laticrete "Ad-Mix" and set with 317 mixed with "Ad-Mix"

Sample Four: Noble Seal TS over dusty drywall no drywall compound - set with Laticrete 317 no "Ad-Mix"
Sample Five: Noble Seal TS over clean, lightly primed drywall (primed with "Ad-Mix" - set with Laticrete 317 mixed with "Ad-Mix"

I'll start there Jim.

Jim to be fair how long do you want me to wait before subjecting the test samples to weight load? I will set a "Jig" over each sample and pile bricks on until we reach a failure point. I'll measure the weight of the bricks and we will have some research to go by.

I'll call the test the "DeBruycker Drywall Therory"

...Yes, a modified has better initial tack and ultimate strength, but if it isn't embedded into the fleece well, it could easily end up being weaker than a proper dryset installed properly ...

That is a great line. You should consider politics Jim if your Kerdi job goes South.

Lets flip it around. "A properly installed modified thin set application with Kerdi is most likely stronger than a Kerdi install not set properly with dry set mortar." WTF Where do you come up with these lines Jim? Are then in your training manual or is that one of CX's old lines???

Survey Update;



JW