[badbillygoat]

Hi all, first post! I am a new DIY'er motivated by the purchase of my first small bungalow house! It is nearly a hundred years old, and built like a bomb shelter.

I have dove into remodeling the bathroom, which has original tile. I thought I would be able to scrape it off of some thinset to find a membrane or maybe subfloor below. However, nothing but a sledgehammer could even loosen any of the tiles, and I quickly learned they were set in 4 inches of concrete!

After removing the tiles, I am thinking pouring some kind of self-leveling concrete on what is left of the slab to give myself a fresh surface to put some large format tiles on. My two questions are:

1. What product would you recommend that would (1) create a stable bond with the existing rough concrete slab and (2) provide an appropriate surface to either put thinset on for tiling or membrane attachment?

2. I would like large format tiles, but I'm scared of installing them and having them crack subsequently (this will be my first tiling experience). Would you put a membrane between the concrete and the tile for some extra leveling and controlling any expansion contraction variances, or is going concrete straight to tile good enough as there is no wood in the system that will move significantly?

Thank you!

 

[SW Dweller]

SERIOUSLY doubt that the tile was set in 4" of concrete.
First concrete has stones and what you want is either mortar or mastic. (smooth no stones)

I have never been a fan of multiple surfaces to get a bond with.

I would be using a roto hammer with a 4" spade bit. Then you can try to "peel the tile from the floor.
After your done, then put a level on the floor and see how much you need to make up. I have seen stone floor set with an inch of mud under them. I have a trowel with 3/4" notches. Used it once for a un level floor. The deep trowel in the areas I needed to raise.

 

[ClarenceBauer]

SERIOUSLY doubt that the tile was set in 4" of concrete.
First concrete has stones and what you want is either mortar or mastic. (smooth no stones)

I have never been a fan of multiple surfaces to get a bond with.

I would be using a roto hammer with a 4" spade bit. Then you can try to "peel the tile from the floor.
After your done, then put a level on the floor and see how much you need to make up. I have seen stone floor set with an inch of mud under them. I have a trowel with 3/4" notches. Used it once for a un level floor. The deep trowel in the areas I needed to raise.

For a house that old you may very well have a thick mortar bed check the detail lower center attached page.

 

[badbillygoat]

I may have exaggerated by an inch or so, but sadly it really does appear to be concrete, stone, a lot of hard stuff to get through. See the picture below for a cross section.

I'm thinking I won't bust through all of it, just enough to get the old tile off, then pour something (recommendations?) To get it nice and level for a new layer of thin set and tile.