Levelling a clay tile floor

[fsn97]

Hi,

We have just taken out the dividing wall between the kitchen and diner in a 1930\\\'s house, and would like to put ceramic floor tiles. As expected the floor levels are not equal. The dinner has a wooden flooring, which I am going to cover with 12mm external plyboard to give me flat surface. The kitchen had old vinyl tiles, which I have taken out. Underneath are red clay tiles, which sit on soil. The difference between the kitchen and diner floor will be about 35mm (after putting the plyboard).

I have a couple of questions.

1. I presume I cannot use a self-leveller as its more than 10mm thick. Is this correct?

2. I think i need to screed the kitchen floor, however, will the screed stick to the clay tiles and do I need damp proof membrane.

Any suggestions will be appreciated.

Thanks

 

[mattysupra]

Yes you can go deeper than 10mm depending on what product of levelling compound you use. But i would recommend you dig up the floor and replace with new concrete/screed, dpm and insulation.
Problem is you are asking for trouble going that deep with levelling compounds over unstable and damp tiles. Manufactories wont guarantee there products.

 

[fsn97]

Thanks for the reply mattysupra,

If I take the clay tiles out, do I have to put concrete or can I put DPM, then Insulation, and finally screed.

thanks