Laying tiles. Is floor gypsum enough?

[jonaslatt]

I laid tiles in the hallway, 3 sqm, a year ago. Also installed an electrical underfloor heating system. Large tiles 30x60.

But after a few days, the grout cracked and I realized I did everything wrong.

I placed the tiles on moving material directly on the chipboard.
And, of course, with cc60.

Is it enough if I remove everything again and lay floor gypsum, then the heating system, and then the tiles?

 

[Åsa Lund]

You must have cc30 on the beams

 

[jonaslatt]

Okay. Must must or must. Often it is the case that you should have certain things. But it still works. I know that builders say cc30. Is it not impossible to succeed with 60?

 

[hempularen]

Njaa. If you glue the gypsum board correctly to the chipboard, there are special adhesives for the purpose, such as those from Ardex. Then the chipboard and gypsum together become a stiff board. It should then be OK with cc60. But note that it must be the right type of adhesive. Alternatively, you can use self-leveling compound about 15mm (varies slightly depending on the brand). This provides the same stiffening.

 

[Stefan N]

You have already tried doing it wrong, now try doing it right instead.
If you don't want to use cc30, you must reinforce and use floor leveling compound.