tavy thin skin underlayment

bublsort

Hi all,

I have some tile that meets up with a hardwood floor, and the subfloor is plywood. I have been looking into underlayments and bought some Ditra, but even the height of that is a problem, since I estimate it will put the tile 1/4 inch above the hardwood. (It's close to even when you put the Ditra and tile right on the plywood without the mortar).

I was trying to find the 3mm Easy Mat when I came across this Tavy "thin skin" product, which is some kind of membrane that you glue to the plywood.

From what I read people who have tried it were satisfied but most are too wary too even try it.

It's only about a 20 sq ft area though if it goes well we might use it elsewhere. I'm not worried about the difficulty of glue because I just put in a ton of glue-down bamboo flooring.

Any thoughts? thanks a lot.

Bud Cline

That product is a waste of your money forget it. The only person in the tile industry that likes the product is Armand Tavy, its inventor. It does not have the blessing of any authority that I am aware of.

Tell you what you do. Go buy some unmodified thinset and buy some compatible additive and mix your own modified thinset. Apply your tile directly to the plywood. You will be fine in this case if you do it the way I am suggesting.

bublsort

Really? Because the one thing I've heard about a million times is don't put tile on plywood...

Bud Cline

Okay then you do what you think is best, forget about me.

I will tell you that tile has been installed successfully over plywood since plywood began. The problem is...better methods are now available and installing tile over plywood being done by idiots that cheap out is problematic.

If you do it like I have suggested you'll be fine assuming the correct plywood is used and the correct thinset mixing method I suggested is used.

I'm not here to argue about it, you do what you think is best. You are the one that wanted to hold the tile elevation to a minimum. This is how you do it.

My advice is to use backerboard but you are the one that has already poo-poohed that idea.

bublsort

I don't know what's best, that's why I'm asking, I just heard several times to use an underlayment, but I can be convinced otherwise. What is a compatible additive? I don't know what kind of plywood it is.
I have some unmodified thinset already for the Ditra.

Bud Cline

All thinset manufacturers also have a compatible additive for just such purposes. I would suggest Mapei's Kerabond with their Keralastic additive.

Where are you using the unmodified thinset you have now and what brand is it?

bublsort

I haven't used the unmodified thinset at all yet, it was for the Ditra which as yet we haven't put down anywhere. I don't know about the brand, I'll have to check when I get home. It was the only unmodified thinset that they carried at home depot. They did have some kind of additive that went with it, but just the one I think.

Bud Cline

That would be "Custom Blend", the low end of the low end unmodified thinset products. It isn't what you want to use in this case to install DITRA. Go to Schluter's website and read-up on their recommendations for what type of thinset to use where when installing DITRA.

I also wouldn't suggest using Custom Blend even after adding the additive for installing tile over plywood.

bublsort

Yeah, that sounds familiar. the Schluter site just gave an ANSI number, that's it, not a brand. What is a good brand? and where can I find it?

Oh I guess that would be the Kerabond?

bublsort

So! I went to the lowes that carries the mapei brand, and they had everything except kerabond / keralastic. They apparently could order the kerabond but not the keralastic (though I had the feeling if I talked to a different guy it might be possible)

They have some other Mapei thinset called kerafloor, which can be mixed with keraply.
They also can order Laticrete 317 which can be mixed with "super flexible additive" Laticrete 333. I read somewhere about that being another good option. What do you think?

Justgaff

You can install on 'plywood' but not OSB... There is a difference! Sanded veneer core PLYWOOD underlayment....

Bud Cline

Scheeesch! And I thought we had progressed beyond that point already. Now we are taking back-steps.

bublsort

I swear, i am doing my best to locate either kerabond/keralastic or Laticrete 317/333 but neither one is on the shelf and lowes or home depot and for some reason I can't find employee who knows how to order them.

Any other good brands? Or places to look?

Ps it is definitely not OSB, it's plywood.