Tiling to gypsum based substrates/backgrounds.

[Dave]

It's a good marketing ploy though as the gypsum addy is a premium compared to cement based.
I've done one Gyvlon with a cement based addy & it failed but it was tiled in 7 days as the builder wanted clients moved in & his money & floor would get sorted at a later date.
I suppose this has always stuck in my mind even though I know why it failed, I've never had bother tiling to plaster so why should I have bother with a screed!!

I bet that scared you some ...


the the problem is stef , with anhydrite being quite new to most of us , we are easily lead to believing the word of reps.

 

[Stef]

Is this a gypsum screed stef ? If so , then I've not levelled one before , but I do know there are gypsum levellers now lol.. But as you say , if the screed is dry and primed correctly , then yes Imho a cement based slc would be fine.. But do we take the risk is another question ?

Yeah, got told it was a Gyvlon but it's came from Bardons.
I recommended the company to come in & they made a pigs ear of it.
Doesn't look great for me, I've tiled a few of their screeds & they are normally perfect.
I've used Anhylevel on a floor & it's good stuff but the whole point in getting this screed laid was so it was flat & needed no extra prep!! [emoji35][emoji35]

 

[Sean SML Tiling]

Weber told me that it needed priming neat 1 way then diluted 3:1 the other and then use non flexI with the additive. The I was told that it was to be primed 4:1 both ways and then 2 part addy again. Then I was told 4:1 priming both ways and that flexible adhesive is to be used. How was I supposed to be confident going into this world of anhydrites with advice like this. I do agree with you if it's prepped properly with the moisture levels correct there shouldn't be any issues what adhesive is used.

 

[Stef]

I bet that scared you some ...


the the problem is stef , with anhydrite being quite new to most of us , we are easily lead to believing the word of reps.

I had already done my research & knew what the outcome was going to be so I was prepared for it.
Had a lengthy discussion with the builder but as usual some just see the ££ signs..

 

[Dave]

Weber told me that it needed priming neat 1 way then diluted 3:1 the other and then use non flexI with the additive. The I was told that it was to be primed 4:1 both ways and then 2 part addy again. Then I was told 4:1 priming both ways and that flexible adhesive is to be used. How was I supposed to be confident going into this world of anhydrites with advice like this. I do agree with you if it's prepped properly with the moisture levels correct there shouldn't be any issues what adhesive is used.

Thats mad :mad2:...

it it states on the pr360 bottle how to use it for anhydrite screeds... So why would a rep advise otherwise ffs.

pr360 is 4:1 and 4 to 5 coats allowing for drying between each coat.

 

[Sean SML Tiling]

Exactly. My confusion was to why they advised 2 part because it's anhydrite. Concerned me as they didn't know their own products so I lost faith and went for gypsum.

 

[Stef]

In CTD in Glasgow they have a load of leaflets sitting from Weber explaining procedures to tile to anhydrite screeds, I've never seen one getting picked up & the pile never seems to go down any!!!

 

[Stef]

After past experiences with reps , I would not take a reps advice ever again lol.. Most are new to the game and TBO ain't got a clue.

This forum is by far the best place for advice & would ask on here before getting advice from reps..

 

[Just Rizzle]

you know my opinion dave like for like on floors

 

[Just Rizzle]

for all those who have replied how many recommend decoupling mats?

 

[Dave]

you know my opinion dave like for like on floors

what products did you use before gypsum adhesives ? And do you use Anhyfix on walls that are skimmed ? , if not then can I ask why PLZ ?

 

[Stef]

for all those who have replied how many recommend decoupling mats?

Don't recommended a mat unless it's stone.

 

[Rookery]

On the few occasions I've encountered a gypsum screed I've always used cement based addy. I've always sanded and primed the floor first and never had a problem. Equally, I prime plastered walls before using cement based addy.

 

[Rookery]

Don't recommended a mat unless it's stone.

Same here.

 

[peteablard]

Have only ever fitted porcelain to it and never decoupled again at the builders request. Would do if fitting stone though