Anhydrite Screeds: Are You Confident When Tiling To Them?

[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..

 

[DHTiling]

That will be dry in no time... then cool down slowly... and test.

 

[Stef]

That will be dry in no time... then cool down slowly... and test.

Found out from client today that they have knocked a further 2 weeks off the entry date.
They move in 6th September.

What is the shortest time you have tiled to a Gyvlon screed from pour to tile?
This screed is 80mm deep.

 

[Ian]

80mm is very thick Stef, usually half that. That's gonna take a bit of drying out IMO.

 

[Mr Tiler]

House builder down our way getting sued for £110k,

why are they claiming so much?

 

[Stef]

why are they claiming so much?

Full downstairs tiled.
A large m2 area, don't know much more about the build.
The house builder I work for lost out to this company at the tender.

 

[Mr Tiler]

110k sound like he bodged the whole house lol sound mate

 

[White Room]

110k sound like he bodged the whole house lol sound mate

£110k does sound excessive, perhaps they want an extension out of it....

 

[Mr Tiler]

but as stef said hes a builder maybe he done more work than tiling sounds like a dear game to me lol

 

[White Room]

but as stef said hes a builder maybe he done more work than tiling sounds like a dear game to me lol

It is when it goes belly up....

 

[DHTiling]

80mm is very thick Stef, usually half that. That's gonna take a bit of drying out IMO.

Sorry but the norm is 65mm.

 

[DHTiling]

Stef..

The quickest one I tiled to was just under 4 weeks old.

Screed was poured and left for 10 days , then slowly heated till up to force drying temp.

Then force dried for 14 days.

 

[Stef]

Cheers Dave,
You know what's going to happen,
Get it tiled it will be ok.
I've spoken to the client so they know where I stand on the issue.
Going to keep force drying it till the middle of next week & then turn the heating down & do the test.
If its allowed to cool too quick will it crack?

 

[Ian]

Sorry but the norm is 65mm.

Well I've never seen one as thick as 80mm and the minimum depths quoted are as low as 25mm

 

[DHTiling]

But it is gyvlon screed and it is heated , so there is a minimum cover to the pipes. .

 

[Ian]

But it is gyvlon screed and it is heated , so there is a minimum cover to the pipes. .

Fair point, the UFH is in block and beam on the job I'm doing at the mo, so the screed isn't being used to encapsulate the pipes. 80mm is still a bit OTT though

 

[Ajax123]

Gyvlon minimum cover to pipes is 30mm plus the pipe say 16mm so 46mm .... Would normally be specd at 50mm minimum nominal 55mm. 80mm is ridiculously deep an will take a lot of drying.

 

[Ajax123]

House builder down our way getting sued for £110k,
Tiled with Marble on top of a Gyvlon screed & every tile has lifted.

At £50 per square meter that is 2000 square meters. I don't beleive it personally... It's too much to be just the tiling IMO. Builder has probably done lots of stuff wrong and the tiling is just one bit. This sort of "statement" really frustrates me as it is made in haste and is unsubstantiated yet it automatically gets associated with anhydrite screed yet is probably nothing to do with it.....

 

[Stef]

At £50 per square meter that is 2000 square meters. I don't beleive it personally... It's too much to be just the tiling IMO. Builder has probably done lots of stuff wrong and the tiling is just one bit. This sort of "statement" really frustrates me as it is made in haste and is unsubstantiated yet it automatically gets associated with anhydrite screed yet is probably nothing to do with it.....

It came from the guys that pumped in the screed.
This house builder has a reputation for some dodgy workmanship.
Every tile has lifted on top of the Gyvlon screed.

 

[Stef]

Well we had a good bit of news today regarding this installation,
The heating is getting turned down & switched off & there is a further moisture test taking place next week.
Hopefully they are starting to listen to me regarding this screed.

On another note the builder foned Bal technical & they told him, "contact Schluter, they have a membrane that you can put down on it".

I'm glad that you guys on here have put me in the picture as this kind of advice is not helpful.

 

[Ajax123]

It came from the guys that pumped in the screed.
This house builder has a reputation for some dodgy workmanship.
Every tile has lifted on top of the Gyvlon screed.

Hmmm ok must be a flipping big house and flipping expensive tiles...