Decoupler and anhydrite

[White Room]

They do say in there book to seal with weber PR360

 

[Ajax123]

If all is perfect I.e. The screed is dry and properly cleaned and vacuumed and primed with typically two coats of primer there is no reason to expect a problem. The issue is that the system is jot robust to "poor" workmanship.... Using the phrase in the least offensive way I can ..... whilst I know of hundreds of tiled floors using cement which are fine I have also seen lots of failures as well. I have yet to see a failure with gypsum on gypsum. It seems a more robust system to me. It is more the norm in Europe ... Especially France where something like three million plus square meters will be laid and tiled this year

 

[Gazzer]

Why have weber got it in their "Tile Fixing Solutions" book that u can go over a sealed Anhydrite screed with almost all of the cement based addys?? I know you & Dave have tried a few different addys for this screed. Cheers folks.

Only if the floor is dry though !

 

[Stef]

I take it this screed is going to be the way forward in terms it will probably replace a cement based screed?
This has been a nightmare for us so far & its just goin to keep getting worse, i would love to wipe my hands of it but my partner has worked for this guy for 14/15 years so its not as easy as just walking away.

The only good thing will be that we can walk away from this with our reputation still intact as we are dealing with him direct.
How hard is it to get the old adhesive up from an Anhydrite screed? Gypsum & Cement based addys? Worst case scenario we go back for the repair in 2/3 months time, by that time it will be dry.

 

[Gazzer]

I take it this screed is going to be the way forward in terms it will probably replace a cement based screed?
This has been a nightmare for us so far & its just goin to keep getting worse, i would love to wipe my hands of it but my partner has worked for this guy for 14/15 years so its not as easy as just walking away.

The only good thing will be that we can walk away from this with our reputation still intact as we are dealing with him direct.
How hard is it to get the old adhesive up from an Anhydrite screed? Gypsum & Cement based addys? Worst case scenario we go back for the repair in 2/3 months time, by that time it will be dry.

I guess its the way forward until something else comes along. I hear a few major house builders will be using it as standard from January.
I also wonder how we will get on when a few years down the line and you turn up at a house to tile the floor and you don't know for sure if its Anhydrite/Gyvlon or normal screed ? What about when there are 2 differing screeds ie original sand and cement from an old house and teh extension they have just had built is Gyvlon ?? gotta be 2 adhesives ?

I have had 4 Gyvlon screed floors offered to me in the last 2 months, One I turned down due to the client being very uncooperative when I voiced my concerns, he wanted it done right but did not want to wait or be inconvenienced at all.

 

[Stef]

I guess its the way forward until something else comes along. I hear a few major house builders will be using it as standard from January.
I also wonder how we will get on when a few years down the line and you turn up at a house to tile the floor and you don't know for sure if its Anhydrite/Gyvlon or normal screed ? What about when there are 2 differing screeds ie original sand and cement from an old house and teh extension they have just had built is Gyvlon ?? gotta be 2 adhesives ?

I have had 4 Gyvlon screed floors offered to me in the last 2 months, One I turned down due to the client being very uncooperative when I voiced my concerns, he wanted it done right but did not want to wait or be inconvenienced at all.

It would be great if we all lived in an ideal world where everyone listened to each others concerns & advise & we went about jobs by the letter of the law!!! aye we all wish.
Sir Ramic you have a very good point there, i know very little about Gyvlon screeds, only what i have read on posts here, & it sounds a bit of a headache also.
We are running 3 sites just now but we havent heard anyone speak about new screeds yet. at least with these posts we will be prepared for if & when it does come.
I will keep you posted when this job goes belly up!!:nopity:

 

[Gazzer]

It would be great if we all lived in an ideal world where everyone listened to each others concerns & advise & we went about jobs by the letter of the law!!! aye we all wish.
Sir Ramic you have a very good point there, i know very little about Gyvlon screeds, only what i have read on posts here, & it sounds a bit of a headache also.
We are running 3 sites just now but we havent heard anyone speak about new screeds yet. at least with these posts we will be prepared for if & when it does come.
I will keep you posted when this job goes belly up!!:nopity:

The builder who has had these 3 floors I am about to tile knew nothing of the concerns of floor layers regarding the Gyvlon. he went along with what the screeder suggested. Its early days for us all but we all need to know the score, the internet and forums like this are one of the best ways of keeping on top of things.

 

[Stef]

The builder who has had these 3 floors I am about to tile knew nothing of the concerns of floor layers regarding the Gyvlon. he went along with what the screeder suggested. Its early days for us all but we all need to know the score, the internet and forums like this are one of the best ways of keeping on top of things.

Totally agree with you there, This forum is worth its weight in gold, No matter how long you been at it theres always something to learn.

 

[Gazzer]

Totally agree with you there, This forum is worth its weight in gold, No matter how long you been at it theres always something to learn.

Amen to that, its the folk who think they know it all that I worry about. Times are moving and we all need to move with them .

 

[Ajax123]

I certainly hope anhydrite is the way forward...... My livelihood certainly depends on it. Robson, you can always ring me at work if you need some advice 07545 932723

 

[doug boardley]

Robson. If you use cement it WILL fail. If you use gypsum it MIGHT fail. If you use cement it will delaminate along with the tile thus leaving the tiles un useable. I have never seen a failure with a gypsum day yet but my understanding is that the failure due to moisture is at the tile addy interface. This means that the tiles would come away clean and be reusable. Not sure if this is true or not. This job could be the way to find out though cos sure as eggs is eggs if you tile it next week it won't be dry. The underfloor heating should also be commissioned. This one seems doomed. The trouble for you is that as a professional you are accepting a contract and carrying out an installation that you know to be incorrect. A disclaimer may not cover you and you could end up liable for the inevitable repairs. My personal advice ........ as a self confessed anhydrite expert....... Walk away from it or do it properly. At 70mm which itself is far too deep you will be looking at two months.

what is the optimum depth for a gyvlon screed Al?

 

[Ajax123]

As close to the minimum depth as possible.40mm floating commercial unheated35mm floating domestic unheated30mm cover to heating pipes so 45mm on 15 mm ugh pipe and 50mm on 20mm pipes30mm unbonded25mm bondedAnything more is un necessary but screeners are often forced to put more in by poor specifications and poor building quality.

 

[Stef]

I certainly hope anhydrite is the way forward...... My livelihood certainly depends on it. Robson, you can always ring me at work if you need some advice 07545 932723

Al, thanks very much for that, we will see the boss tomorrow morning & see how he wants to go about this. Talking to my business partner today & told him all about this scenario, we are going to try & talk him into putting down linolium for the time being then we will go back & tile once the floor has fully dried out. :mad2: (this is what i will be doing)

 

[doug boardley]

As close to the minimum depth as possible.40mm floating commercial unheated35mm floating domestic unheated30mm cover to heating pipes so 45mm on 15 mm ugh pipe and 50mm on 20mm pipes30mm unbonded25mm bondedAnything more is un necessary but screeners are often forced to put more in by poor specifications and poor building quality.

any chance of having that in english Al??:lol::lol:

 

[Ajax123]

Al, thanks very much for that, we will see the boss tomorrow morning & see how he wants to go about this. Talking to my business partner today & told him all about this scenario, we are going to try & talk him into putting down linolium for the time being then we will go back & tile once the floor has fully dried out. :mad2: (this is what i will be doing)

Then sadly you would be making a mistake.........no offense intended. The screed dries purely by evaporation from it's surface. Covering it with an impermeable covering would stop it drying......you coul put a breathable carpet down. It would be best though to commission the heating and force dry the screed over the next two or three weeks then tile it using a gypsum addy

 

[Stef]

Then sadly you would be making a mistake.........no offense intended. The screed dries purely by evaporation from it's surface. Covering it with an impermeable covering would stop it drying......you coul put a breathable carpet down. It would be best though to commission the heating and force dry the screed over the next two or three weeks then tile it using a gypsum addy

i wasnt sure if you could force dry the screed, wasnt sure if it would crack it. i assume the heating has been commissioned by now i will find out tomorrow.
i told you this was just going to keep being a nightmare for me, happy days. will speak to him tomorrow & see what he says about this.
thanks again Al for your help on this matter its appreciated.

 

[DHTiling]

Commissioning the screed is the quickest way.. These screeds are going no where, so get to know them and you will be fine..

We need to get some more training days sorted..

 

[Ajax123]

Commissioning the screed is the quickest way.. These screeds are going no where, so get to know them and you will be fine..We need to get some more training days sorted..

I'm up for that Dave. Just let me know when.

 

[Stef]

Any chance of doin a course up in sunny Ayrshire? ha. i would like to attend a course on this especially if its goin to get more common as a screed.

I take it anhydrite will not crack if you force dry it then? would a dehumidifier also help? need all the info i can get so i can show him this tomorrow.

 

[DHTiling]

These might help..

View attachment Calcium Sulphate Tech sheet Apr10.pdf

View attachment gyvlon screeds 2.pdf

View attachment Gyvlon screeds 1.pdf

 

[Ajax123]

Any chance of doin a course up in sunny Ayrshire? ha. i would like to attend a course on this especially if its goin to get more common as a screed.I take it anhydrite will not crack if you force dry it then? would a dehumidifier also help? need all the info i can get so i can show him this tomorrow.

Force drying is actually a recommendation. Take a look at some of the tech data sheets at Lafarge Gyvlon Anhydrite based Calcium Sulphate Flowing Screed. That would help you a bit. The one on drying a gyvlon screed section 3 gives you the procedure but alter it slightly so that you maintain the highest temperature for 7 days instead of just three. No reason to expect it to crack.

 

[Stef]

Cheers folks, if i show him all this then maybe he will realise that its a good idea to wait.

"ALL GOOD THINGS COME TO THOSE WHO WAIT"

 

[Ajax123]

Cheers folks, if i show him all this then maybe he will realise that its a good idea to wait."ALL GOOD THINGS COME TO THOSE WHO WAIT"

If he don't listen put him in touch with me and I shall talk him through it as a suppliers technical manager

 

[Stef]

these were the two floors we tiled over anhydrite screed, the boss wouldnt wait, he knows we are going to be back to sort them but he just wants the clients moved in & then deal with snagging in a couple of months.:mad2: we ended up just using a flexi concrete adhesive in the hope it would delaminate the adhesive from the screed & hopefully delaminate the adhesive from the tiles, we did a test patch & it lifted off the screed but adhesive is solid on the back of the tiles, the boss will just have to go back to porcelanosa & buy more of the same.

Good news is though the next conversion wont be ready for us to tile until the end of November & they are pumping the screed in next week so they are learning, slowly.

 

[White Room]

Client moved in and doing snagging, thats going to be a nightmare..