Decoupling required on a Gyvlon screed?

[richard8688]

Just looking for some clarification.

I have a 28 sq metre screed slab, Gyvlon Thermio liquid screed, with wet UFH. The laitance has been taken off and it's fully dried. There are no cracks.

After its been primed with APD, will BAL rapid set flexible fibre be ok without a decoupling mat?

The BAL docs say 'may' be used. They appear to only say that the mat is mandatory on wooden substrates.

If a mat is requied, how much adhesive should go under it and on top? 6mm notch trowel above and below mat?

Tiles will be travertine.

Using the mat adds another £500 of materials...ish... 2 layers of adhesive and the mat...


Cheers!

 

[Time's Ran Out]

It's travertine -
Personally I'd use Tilemaster primer, Tilemaster Gyvlon screed adhesive , Ditra mat, Tilemaster fast set flexible white adhesive, Tilemaster beige grout 3000.
Make sure the UFH has been run and off before tiling.

 

[Lee@emctiles]

same as above, TM do an anti fracture mat if you want a one stop shop for everything.

And yes, it is advised a decoupler is used when natural stone is being fitter ontop of ufh.

 

[richard8688]

Thanks chaps!

If I'm using a decoupler, what trowel notch sizes would you use below and above the mat? 3mm below, 6mm above? Or still use a 10mm circular on top?

 

[hmtiling]

Thanks chaps!

If I'm using a decoupler, what trowel notch sizes would you use below and above the mat? 3mm below, 6mm above? Or still use a 10mm circular on top?

I would use 4mm below and 10mm above with tiles back skimmed. I use a Karl Dahm underlayment roller for ditra/durabase which i find very handy

 

[Time's Ran Out]

I use Doc Martins size 8 and 13 stone body weight!
Under the Ditra 4mm and above whatever I pick up to fit the tiles as I trowel the floor and the tile.

 

[widler]

I'd use the TM matting along with primer, tilemaster anylfix and use stamdard s1 or rapid o top of matting.
Or equivalent😉

 

[Dumbo]

Me being picky I use 4mm notch under Ditra or dural and 3 mm under flat mats like bal rapid Matt.

 

[richard8688]

So TileMaster is a better choice than BAL, yes?

 

[Lee@emctiles]

So TileMaster is a better choice than BAL, yes?

i dont think there is much of a difference in the two @richard8688