Anhydrite Screeds: Are You Confident When Tiling To Them? - TilersForums.com

[Andy Allen]

hope you got good money on this job stef. sounds like your going to be going back and fourth like a yo-yo..

 

[Stef]

Ah, the heating wasn't switched off.

I done a sweat test on the floor last week & the moisture underneath the polythene was major.

The company that done the screed reckoned the test was done too quick but I don't think they are too sure on how to test the screed as I was telling them what to do & how long the hygrometer should be in place.
They said 24hrs, I remember Alan stating that it should be minimum 48hrs maximum 72hrs.

I didn't realise that the heating must be off 1st.

I have a hygrometer sitting with a company in Glasgow but I'm that busy I can't get there to pick it up.

 

[Stef]

hope you got good money on this job stef. sounds like your going to be going back and fourth like a yo-yo..

It's ok Andy, I've got just over 200m2 to be contented with. About 80m2 is the downstairs floors & that's the Gyvlon screed.

Luckily it's only 5/6 mile from my door.

 

[DHTiling]

These will be useful for anyone tiling to Gyvlon LL ..


View attachment Gyvlon screeds 1.pdf

View attachment gyvlon screeds 2.pdf

 

[Ajax123]

It's getting forced dried just now Dave.
The heating has been on for just over 2 weeks.
I told them I didn't think you could do anything else to aid drying but I would ask the question.
It's not been sanded yet, I told them to sand it after 2 weeks but its still not been done.
We will see what they want to do..

Aaaaarghhh!! Should always be sanded before the heating goes on. The heating will "bake" the Laitance on and it might be really hard to sand.

 

[DHTiling]

Aaaaarghhh!! Should always be sanded before the heating goes on. The heating will "bake" the Laitance on and it might be really hard to sand.

How many floors get sanded before the heating goes on , none i have done lol lol ,, always heated before i even get told it is too tile.. but 60 grit floor sander puts pay to them

 

[Ajax123]

How many floors get sanded before the heating goes on , none i have done lol lol ,, always heated before i even get told it is too tile.. but 60 grit floor sander puts pay to them

Another "what actually happens versus what should happen" scenario

 

[Stef]

I sanded a bit by hand to stick the hygrometer down & it wasn't too bad to do, it was a heavy grit sand paper though.
You could see the colour of the screed changing when it was being sanded.
The powder that it produces (laitance) is really fine, no wonder it has to get hoovered up..

 

[Peter]

Not done one yet but feel confident about how to handle them. None of my house builders push them on new builds (or perhaps know what they are) but there will come a time when they're getting retiled.

Know of a few tilers locally who have got into bother from assuming they're just like a sand cement screed and getting on the job, striking a line, mixing a bucket and sticking tiles down. Aware of one court case at present.

 

[Stef]

House builder down our way getting sued for £110k,
Tiled with Marble on top of a Gyvlon screed & every tile has lifted.
Not sure what the prep was but something has went wrong & they haven't followed proper procedure.

Dave, I turned the heating up to just below 50 degrees today, it was set about 40/42.
They are still trying to take a moisture reading, told them its a waste of time..