Scratch Coat

Speed3C

Good morning all.

I have a 1 year old kitchen floor with builders cheap ceramic tiles. My wife wants tumbled marble, which I can do, but I'd like to know if I have to remove the scratch coat or can I simply lift the tiles and stick the new ones on top of it?

Thank you

Bud Cline

What is there now is not known as a scratch-coat. That's a different building product and process.

What is there is more than likely thinset mortar. Once you remove the old tile the resulting remaining mess you will have will not be suitable for new tile without some additional preparation.

Is this subfloor wood or concrete?

If it is wood you should first know that most floor structures aren't suitable for a stone tile installation such as marble. Marble requires a floor structure that is twice as strong as that required for ceramic tile.

If you will provide us with your floor structure criteria we can check it out for you.
We need the size of the floor joists and their wood species if you know it.
We need to know the spacing of the floor joists.
We need to know the unsupported span of the floor joists.
We need to know the thickness of the subfloor and what it is made of (plywood, OSB) and how many layers of subfloor are there.

Speed3C

I have plywood. The studs are 16 inches apart.

What would I need to do to reuse the thinset I have?

Blondesense

You really should make sure your subfloor can handle it before proceeding.

Bud taught me a lot when I was trying to tile a couple of projects.
You gotta help him help you though. Answering ALL his questions would be a start.

BTW, have you tried to "simply lift the tiles"? If you haven't, and if the builder did everything right, you may find it ain't gonna be that easy.

OTOH, if you think it will be easy because you already have loose tiles, that can be an indication your floor is inadequate.

Bud Cline

Well Speed,

That was real helpful.

If you don't care then neither do I.