Will thinset stick to Redgard on walls?

[mike_lee]

I have my Permabase installed on studs and I was going to Redgard it but
my tile installer told me that thinset (we are not talking about mastic) would not
stick to Redgard as well as it would to bare cement board and that tiles would
fall off in time if he installed over Redgard. Is this true and do you guys have
experience (some long-term data) with installing wall tiles over Redgard in a
shower? When I started reading Redgard fact sheets carefully, indeed, they
only talk about (guarantee) floor installations and say nothing specifically about
walls.

Thanks,
Mike.

[Madison Mike]

You''ll be fine with thinset over Redguard on walls. It's recommended for waterproofing niches, shelves, and entire shower walls when tar paper or poly are not used as a vapor barrier behind the CBU.

Have your tilesetter buddy visit this site. He'll learn a lot.


Mike
Madison, WI

[muskymike]

Hi Mike, welcome! What the Mad Mike said.

[jdm]

Just be sure to use a modifed thinset over the RedGard and you'll be fine. RedGard was developed specifically to be used under thinset.

[mike_lee]

Thanks,

I am planning to use Flexbond, also made by Custom Building Products which
contains calcium carbonate (Redgard contains it as well) among its ingredients.
Is there a better thinset? There is Laticrete 255 which has Kevlar built in and will
not sag but I don't know about its compatibility with Redgard.

Mike.

[Oldrem]

I know Versabond by Custom definitely sticks to it.

[dpeder]

I also agree with Eric Versabond sticks extremly well to the Redguard. In your case I fail to see the reason for using the Flexbond thinset which will cost you more of your hard earned dollars???? Versabond would do the job with no more effort and less cost

Don

[Wildo]

I have used regard alot for warranty purposes. What I know is on tare outs where regard was used sure makes it easy when the coverage with the redgard is all over because the membrane is what release's from the hardy backer. Water barrier yes. On floor's perfect for stress cracking and water barrier. It's the strength of the regard itself that can't handle the weight of thinset and tile so just applying it to the seam's of the hardy board so the thinset can grab the board for strength. 2 inch's wide that's all you need. Trust me people can say this and that but when you see the whole wall of tile peel away from the wall and it's the membrane that failed you will be pist.

[cx]

Welcome, William.

You notice this thread's more than ten years old?

What you experienced sounds like a common problem discussed here pretty regularly with a liquid-applied direct bonded waterproofing membrane failing to adhere to Hardiebacker because the surface of the CBU was not properly prepared. Custom Building Products, maker of RedGard has a specific method of mixing the product to act as a primer on very thirsty materials such as Hardiebacker.

There is no manufacturer's approved method of applying such a product only two inches wide on the seams of a CBU installation for any purpose at all. Not sure what you have in mind there, but it's not likely to work.

[jadnashua]

Short answer, if you install RedGard per the instructions, it is not an issue. Failing that, yes, it can fail just like anything else.