Removing mortar over cutback. Will it remove cutback along with it?

[pman6]

I plan to tile over cutback adhesive with modified thinset.
In the future, when I want to sell the house, I will have to rip out the tile again, and put in the fancy trendy tile.

I was just wondering if anyone has removed tiles that were stuck on with modified thinset.
When you chisel out the old mortar, is the mortar strong enough to pull off some of the cutback residue?

[John Bridge]

Hi and welcome. Please give us a first name.

The modified mortar will probably pull off some of the cutback that is not as well bonded as the rest of it. Most of the cutback will remain, however.

A better way to do what you want to do is to use a membrane under the tiles.

[pman6]

I've got a bunch of noob questions.

I understand that membrane like ditra is bonded to the concrete slab with thinset, then thinset tile over that. So doesn't that leave you with membrane + thinset stuck to the floor when you go to replace the floor?

I would love to create a stable floating tile floor.
This house is a rental, and I would like a floating tile floor to last 10 years if possible.


I was reading around the forum and someone mentioned Aquabar fortifiber "tile and flooring underlayment". If that's enough to stick the tiles, I could glue them to the slab here and there, enough to cover the center 90% of the dining room, and then anchor the perimeter tiles directly to the concrete slab. That should hold the whole room in shape for many years?
Then when I go to replace the tile in the future, I only have to chisel out the perimeter tiles.

$20 for 500sqft of aquabar is double the amount of square feet I need, and if it's a decent cheap alternative to Tavy skin, I'll use it.

[pman6]

Redgard on concrete slab.

How do you remove it if you want to change tile in the future?

Or is removal not required? Just remove the old tile, then tile over the old redgard again?

[technical]

Hi Paul,

The mortar A118.4 that is used will adhere far better to Redgard than the RedGard will adhere to the concrete. If you ever decide to change your tile assembly you have no worries. The RedGard will shear at the concrete/RedGard interface.

[cx]

Welcome, Paul.

It'll help if you'll keep all your project questions on one thread so folks can see what you're working on and what's been previously asked and answered. We can give it a more generic title any time you'd like.

I'll hafta disagree with LJ on the ability to predict where the failure of the RedGard bond will occur. The testing for the material to be listed as an A118.10 or .12 membrane requires a shear bond strength of at least 50psi and it makes no difference if the failure occurs on the concrete test block or the tile side.

I think you should just be looking to install your tile now and worry about the demo later. Nobody is gonna be able to specify an installation system that will last ten years and be easy to remove. You can try any of the favorite old methods of installing over roofing felt or other such membranes, but you'll just hafta settle for whatever results you get.

My opinion; worth price charged.

[ivinho]

Hi,

I've had a similar experience with cutback in my basement. While removing some tiles (not ceramic), most of the cutback remained stuck to the slab but the cutback that did come off also pulled out little chunks of concrete with it. The cutback was not even completely dry but had been there for at least 50 years. Im not sure what the condition of your substrate is in, but cutback is really hard to remove. I used a soy based product called Bean-e-doo which removed 90% of the cutback. I then used a diamond grinder to smooth out the floor and take off the remaining cutback. Eventually I decided to paint the basement with Epoxy rather than take a chance with tile. It takes a lot of prep work but the end result is great.