anhydrite

[Ian]

Perhaps they dont know anything !

No perhaps about it. More bad advice from people who should know better.

 

[Ajax123]

I made an enquiry tonight with one of my suppliers regarding a gypsum based adhesive and they said there product will just go straight onto the screed, he never said anything about sanding or priming, I would never stick a tile on a any type of floor without priming, strange how they never mentioned priming to such a problematic substrate, and no mention of sanding!!!!!! any thoughts on that as I assumed the sanding was the most important first stage of installation.

There are adhesives that do not require a primer but there are none that remove the need for sanding. Which adhesive was it?

 

[Mark S]

Even after all these years, Gyvlon entered the UK market in 1996!! there are still people saying utter c**p about the screed, the preparation, drying times etc etc,.
All I can say is if in doubt ask !!, we are here to help and ensure successful installation of foremost the screed but the floor finish as well.

 

[AD Ceramics]

There are adhesives that do not require a primer but there are none that remove the need for sanding. Which adhesive was it?

Hi Ajax123

The adhesive that has been recommended to me is Keracol H40 Eco ideal, no primer just floor abraded and hoovered, now the word abraded would that suggest sanding, when I said scabbled oh no no no that's not good enough so abraded it is, what would you recommend to abrade the surface.
Would you install a ditra or similar anti fracture mat with an 800x800 tile, I normally wouldn't hesitate to use ditra but it has been suggested that it doesn't need it, I beg to differ but thought I would ask you guys, have any of you heard of decomat pro matting, any good?

Cheers guys

Paul

 

[Ajax123]

Hi Ajax123

The adhesive that has been recommended to me is Keracol H40 Eco ideal, no primer just floor abraded and hoovered, now the word abraded would that suggest sanding, when I said scabbled oh no no no that's not good enough so abraded it is, what would you recommend to abrade the surface.
Would you install a ditra or similar anti fracture mat with an 800x800 tile, I normally wouldn't hesitate to use ditra but it has been suggested that it doesn't need it, I beg to differ but thought I would ask you guys, have any of you heard of decomat pro matting, any good?

Cheers guys

Paul

sanding and not scrabbling. Scrabbling is for concrete not screeds. So sand with medium grit paper or 60grit to remove any loose and friable material and damn good vacuum to get rid of the dust. H 40 Eco ideal is perfectly ok with no primer. If the screed is very porous or dusty then a consolidating primer might not do any harm. Would only use decoupler if it is heated and natural stone but with 800x800 it's up to you. It can't do any harm but is probably over engineered. If it natural stone then decoupling is essential.

 

[Gazzer]

I use a floor polisher with sanding disc, works a treat and does not create too much airborne dust due to its low rpm speed.

 

[AD Ceramics]

Would only use decoupler if it is heated and natural stone but with 800x800 it's up to you. It can't do any harm but is probably over engineered. If it natural stone then decoupling is essential.

yes it is heated and porcelain tiles.

 

[Mark S]

Check with Kerakoll, as they have an adhesive specifically for latge format tiles.
H40 is 'Ideal' for ceramics onto Gyvlon screeds, without the need to prime, although some still prime but only to prevent the adhesive drying too quickly.
As with the other posts sand using an orbital type STR machine and 60-7-grit paper, to remove any loose or friable surface material, and to open up the screed surface.
And deffo use a de-coupling membrane

 

[Stef]

Took readings from the hygrometer today,

This Gyvlon was 55mm deep & this is day 53.
Good to go me thinks.
Working right through the holidays.