Anhydrite Screed

[Spare Tool]

Have to go look at a 90m floor on Monday..just came across this and as Webber recommend set plus for the adhesive I would always choose a slowsetting adhesive over a rapid set where possible, I've read many threads on here where it is advised specialist anhydrite adhesive should be used but no manufacturer seem to make a slowset version...is it taking a gamble using a cement based adhesive or as long as its prepped and primed correctly as it states in the Webber advice slowset cement based can be used without worry..or does anyone know of a manufacturer making a slowset specialist anhydrite adhesive?
I should mention the screed is over wet ufh, tiles 600x600 porcelain..
Tiling onto anhydrite screeds - Weber

 

[stone tiler]

I would always go with the Anhyfix if possible. Just a bit more peace of mind for me.
Speak to Tilemaster, they might be able to knock you up a batch that'll go off a bit slower.

 

[Dave]

Its not a gamble imho as long as you prime properly but imwould go rapid adhesive , so it hydrates quicker on the primed screed.. Just the way ive always done it.. And my weber choice would be rapid spf..

 

[Ian]

Yeah set plus isn't the right adhesive to be using, unless you're mixing it with an additive. Anhyfix would always be my choice for and anhydrite screed.

 

[AD Ceramics]

Kerakoll Eco H40 is slow set and suitable for anhydrite screeds, mineral based.

 

[bcd-87]

Its not a gamble imho as long as you prime properly but imwould go rapid adhesive , so it hydrates quicker on the primed screed.. Just the way ive always done it.. And my weber choice would be rapid spf..

@Dave your the stephen hawkins of tiling

 

[Qwerty]

@Dave your the stephen hawkins of tiling

What?.....he's in a wheelchair and talks like metal mickey!!??

 

[AliGage]

I've just done 5 Ensuite floors on a wet heated Anhydrate screed.

Once dry.....

Sanded off the latency.
Primed 3:1 with Weber PR360. It took two coats.
Fixed ditra using weber SPF slow set.

All floors have been down around 4-5 weeks depending on which room it is.

 

[Dave]

I've just done 5 Ensuite floors on a wet heated Anhydrate screed.

Once dry.....

Sanded off the latency.
Primed 3:1 with Weber PR360. It took two coats.
Fixed ditra using weber SPF slow set.

All floors have been down around 4-5 weeks depending on which room it is.

I prefer 4 to 5 coats

 

[AliGage]

After two coats Dave it wasn't absorbing anymore. I had to mop a third off the surface before it skinned over.

 

[peteablard]

I dilute it 4:1 and it normally takes 4-5 coats

 

[Dave]

After two coats Dave it wasn't absorbing anymore. I had to mop a third off the surface before it skinned over.

4:1 ratio for me , prevents possible skinning as you say ...

 

[Dave]

Weber say 3:1 to 5:1 but 3:1 for me is strong ... So i use 4:1 but like anything else , use what works for you ..

 

[Ajax123]

Kerakoll and benfer both do slow set compatible materials. H 40 ideal from kerakoll but can't remember what the benfer one is called off the top of my head.

 

[Tile Shop]

What about BAL APD? They say that only needs 2 coats.... 1st 1:1, 2nd neat. Wouldn't most acryllic primers be the same principle? Mapei said the same thing when i spoke to them about Primer G.

Due to a couple of issues we've been advised of, it seems to me that primer and cement addy is still the safest way to go.