Problematic Anhyrdrite floor!

[The D]

I will not mince my words when it comes to these screeds I do not trust them and I will not tile on to them I will not even offer a quotation if they have been installed.
In fact I hate them and all the BS that goes along with them (and I’m not talking British Standards) the only time I will tile on to one of these screeds is if hell freezes over.

 

[Ajax123]

I will not mince my words when it comes to these screeds I do not trust them and I will not tile on to them I will not even offer a quotation if they have been installed.
In fact I hate them and all the BS that goes along with them (and I’m not talking British Standards) the only time I will tile on to one of these screeds is if hell freezes over.

As is your right mate... 🙂 And to be fair I've never seen you mince your words over anything so far .... 😉

 

[The D]

Harping back to many threads to which I have contributed prep is really straight forward, sand it vac it, prime it (if your adhesive needs a primer) then tile it.

You missed out the moisture test and witch method to use and do we follow your set of instructions or the manufacturers. No don’t bother I have stopped lessoning I am taking my ball and I’m not playing any more

 

[macten]

I swerve these screeds like I would a floating floor.
Why add extra stress and hassle to a job?
I'm Paranoid about identifying them though so they are still having a negative impact on my job and I don't touch 'em.
As for relying on customers to give you all the gen on their substrate or meeting with the screeder or even knowing who the manufacturer is, in the real world, it doesn't happen.
The one time I was privvy to meeting with the screeder was at the beginning of a very expensive project (a lovely reclaimed geo job with wet UFH that I asked the talented Mr Hobson for help with).
Well this screeder really appeared to know his stuff and although anhydrite seemed to be the perfect and most cost effective solution for the customer as his hallway wouldn't have to be dug down so deep, plumbing would be easier, in and out quicker, less dust and quicker to tile too etc...
I managed to talk the customer into going with the more expensive, labour intensive and disruptive cement screed. The screeder did an amazing job as I knew he would - he seemed so knowledgable.
He knew about laitency and potential problems with tiling without removing the laitence first, but the newer stuff he uses was low laitence and needed nothing more than priming and no mention of moisture testing. That's my problem, misinformation between the screed manufacturers between themselves and their installers. Tile adhesive recommendations that differ from each other and can conflict with the screed manufacturers.

I don't want to spend £££s on hygrometers and testing on days when the ambient humidity may or may not be conducive to giving me a result that may or may not be accurate etc...

I wish you anhydrite guys could put something in your screeds that turns the laitence green, neon pink or some other undeniable hue when it's dry enough to tile to - then not only could I recognise it, I could confidently sand it all off and know it's cool for me to tile to. If you guys could do this I would no longer refer to it as 'devil's tarmac'

 

[Dan]

Devils Tarmac. Made me laugh that did.

 

[DHTiling]

I got a full house on Gyvlonn LL to start next week.... nee bother at all.. ... what is the issue with these floors... you tile to skimmed walls . ? just think of a large skimmed floor.. same to prime , just longer to dry..

 

[The D]

Knock your self out m8 it only takes on to go wrong and you are FUBAR

 

[bugs183]

Thats the problem Dave, and i can see your point.
It does seem like no bother at all, and you tile it....
but lots of other guys have done the same, been through the testing as thoroughly as possible and still had failures.
I tiled 120m2 floor several months ago, using Kerakoll Eco.
I explained my concerns to the customer, so the rep made the moisture check, with their preferred method, a carbide bomb test, which i know isn't Ajax's, i mentioned Hair Hygrometer, 'we use these'.
There just always seems to be something wrong, the builder i suggested should use these screeds has had nothing but agro off the screeders. No expansion joints anywhere, tons of latence which no one told him would occur. He then used another firm and the floor took weeks to even firm up, looks like the screeders tried to water the mix down,and now he has a floor that refuses to dry out.
He never touching these floors again.

 

[Perfect Tiling]

I seem to have started quite a rant here...but not the first it seems on this subject. These screeds are fairly rare up here so at the moment I can stay away from them for now. I will just have to reaffirm with the customer that he cannot just turn on his heating with the rest of the floors or the same thing will happen. As to the floors that have started to sound loose, he just wants to leave them for now so what can I do...I can't force him to get them redone. And I can't miss them off the bill when I make it out as that may look like I'm saying its my fault. Thanks to all for their input...it was...interesting reading!!!!

 

[jonnyc]

Thanks Ajax...thats what I thought. As mentioned I didn't sand the floor as screed company said not to...I did try to sand and scrape a part but nothing came off...no dust...nowt. If moisture is the cause who is to blame? I don't do a bomb test and relied on dates given by customer and screed company who now say 120 days not 75 as previously. I told customer not to put up heating but he did so just my word against his. The heating to the travertine floors has been physically shut off for now so that if moisture levels are too high the floor can still breathe and hopefully be ok. Failed floors are porcelain. This type of screed obviously has some benefits...but not as regards tiling onto!!!!

i still havent seen any benefit at all in having these screeds except that they can be laid in a day. everything after that is aggro and more time.
even the notion that you dont need expansion joints through doorways is nonsense and has been proved to me many times unless the screed was badly laid

 

[jonnyc]

If the trav is solid and just the porcs came up after heating, then i think it is a strong possibility that it was heated to quickly.. if the heating was ran for 3 weeks then i doubt much moisture was left in the screed..

porcs will react a lot different to thermal shock than stone as porcs rely on polymers to hold the tiles where as stone with hold in the capillaries/structure of the stone backs.. so the thermal stress will make porcs pop easier if subjected to heat to fast as the adhesive would not be at full structural strength till at least 28 + days.

So don't be quick to blame moisture / sulphate delamination till you see how quick the floor was heated up.

this is a very good point dave. but if the screed under stone still has a bit of moisture in it do you think that if heating turned on say to 20 degrees over 4 days in equal increments held for 4 days and brought down over 24 days this might be ok.I only say this as it does seem that there are far more failures on porcelain than stone floors.

 

[jonnyc]

well i should have read from beginning before posting anything about this but it seems like the same old problem occurring.
now i respect the time you spend helping to educate us and your considerable experience with these screed ajax , but i do not accept your statement that these type of screed are here to stay and we should all embrace and learn or just not bother.
why should they be here to stay?
if enough tilers refuse to tile over them then they will not continue.
its not about being stuck in a time warp either . people of 40 yrs old and above and i would say that is quite a lot of the experienced tilers on this forum have dealt with and adjusted to massive changes within our industry and many of us would truly say that the changes in materials we fix whether finished stone/porcelain or even the prep work has given us a more interesting trade .

 

[jonnyc]

sorry had to start again for fear of losing post.
getting back, there are many instances of a bad product being brought to market and not succeeding.
why not because people did not like it!!
it is ridiculous to tell us that anhydrite is here to stay if we like it or not.
it seems to me there has been some very good sales pitch and patter to convince the average contractor that he is gaining by having one of these screeds.
I can say for myself only that i have counted 18 anhydrite screeds that i have stone and porcelain on to date.
without exception there is not as single contractor that used this screed that has done so again.
this is not because my tiles have failed but simply because beyond the obvious time saving of maybe doing 500 mts in a day in a big house top and ground. the waiting time and prep work they have to do is not worth the aggro. full stop.
perhaps if these screeds were laid in a professional manner as assumedly they are in germany/france then we might profit from an amazing level screed /latence problem sorted by screed company and we could all carry on as normal.
but this is certainly not the case here .

 

[DHTiling]

this is a very good point dave. but if the screed under stone still has a bit of moisture in it do you think that if heating turned on say to 20 degrees over 4 days in equal increments held for 4 days and brought down over 24 days this might be ok.I only say this as it does seem that there are far more failures on porcelain than stone floors.

heated to 20 degs or above in 4 days is IMO too quick.. but it is also how soon the heat is introduced.. not many wait a month to do this..

 

[jonnyc]

I got a full house on Gyvlonn LL to start next week.... nee bother at all.. ... what is the issue with these floors... you tile to skimmed walls . ? just think of a large skimmed floor.. same to prime , just longer to dry..

if only this was so easy dave.
what precautions have you made for this particular job,
have you tested this yourself and if so with what test meter.Or has someone else and if so, have they submitted a report in writing that would cover you in eventuality of any failure .

 

[doddy41]

Woudnt touch one of these floors with a barge pole too many things to go wrong

 

[DHTiling]

if only this was so easy dave.
what precautions have you made for this particular job,
have you tested this yourself and if so with what test meter.Or has someone else and if so, have they submitted a report in writing that would cover you in eventuality of any failure .

It is for a builder i have done tiling for, for a lot of yrs.. he force dries the floors.. last 3 have been done this way... easiest way to get them dry.. you can force dry a floor in 10 days... we run them for 3 weeks.. to make sure they are dry...

Some the damp testing methods are flawed IMO as they give a true reading at optimal conditions etc and not often that happens... we are told you need to do this and that.. then a few months later they change the goal posts and change their advice..

An example of this is the screed reps.. they say to make sure dry and use acrylic or epoxy primer.... NOW!! they say it is best to use a gypsum adhesive that are not even covered under BS..

So IMO force drying when they are heated is the option we go for , if the floor is not heated , then i don't touch .. but not tiled a none heated one yet..

These screeds are here to stay IMO , as they are quicker to lay and stronger than S&C screeds and of course cheaper as the speed of laying out ways the labour of a traditional screed.

When they first started to get mentioned on here , i had not even seen the in my neck of the woods but the past 2 yrs i have come across quite a few and this is the 4th for this builder as he likes these screeds..

This house is Gyvlon LL on both floor levels of the house.. and 3 bathrooms and over 60 mtrs i am told down stairs... the last one was 160 mtrs down stairs and when i first did one i bricked it because of all the scare mongering over this type of screed.. but the more i do the more reliant i am over them..

The biggest issue is the screeder .. they are a nightmare if not controlled properly as they over wet them to speed up the levelling out and this is what can cause friable surfaces and BIG failures.. make sure who ever is there when the screed is poured watches the slump test fro each pour to make sure it is the right consistency to get a nice strong hard screed.

 

[Ajax123]

It is for a builder i have done tiling for, for a lot of yrs.. he force dries the floors.. last 3 have been done this way... easiest way to get them dry.. you can force dry a floor in 10 days... we run them for 3 weeks.. to make sure they are dry...

Some the damp testing methods are flawed IMO as they give a true reading at optimal conditions etc and not often that happens... we are told you need to do this and that.. then a few months later they change the goal posts and change their advice..

An example of this is the screed reps.. they say to make sure dry and use acrylic or epoxy primer.... NOW!! they say it is best to use a gypsum adhesive that are not even covered under BS..

So IMO force drying when they are heated is the option we go for , if the floor is not heated , then i don't touch .. but not tiled a none heated one yet..

These screeds are here to stay IMO , as they are quicker to lay and stronger than S&C screeds and of course cheaper as the speed of laying out ways the labour of a traditional screed.

When they first started to get mentioned on here , i had not even seen the in my neck of the woods but the past 2 yrs i have come across quite a few and this is the 4th for this builder as he likes these screeds..

This house is Gyvlon LL on both floor levels of the house.. and 3 bathrooms and over 60 mtrs i am told down stairs... the last one was 160 mtrs down stairs and when i first did one i bricked it because of all the scare mongering over this type of screed.. but the more i do the more reliant i am over them..

The biggest issue is the screeder .. they are a nightmare if not controlled properly as they over wet them to speed up the levelling out and this is what can cause friable surfaces and BIG failures.. make sure who ever is there when the screed is poured watches the slump test fro each pour to make sure it is the right consistency to get a nice strong hard screed.

David... When was this one laid mate...if you know?

 

[DHTiling]

Around 7 to 8 weeks ago... heating has been on for 4 to 5 weeks... summit like he said 🙂

 

[jonnyc]

dave i agree with much of what you are saying. most of the 18 jobs i have done on these screeds have been forced dried and heating on for three weeks and i have not had a failure yet.
but and it is a big but , you do not mention that there has been a proper test by either you or the contractor.of course everything is fine until it is not!!this is key
but i do know of a problem right now whereby the same force drying has been carried out and the floor has failed. the same careful priming etc had s been carried out .this is now a very serious situation and i am afraid that to simply state that by force drying with no tests is suffice because no problems before does not work in case of law.

 

[DHTiling]

The test Jonny is to only see if they are at the correct RH.. if you heat a screed at high temps for a long period then IMO there is no damp... the builder dries them and gives the go ahead to tile.. his choice .. but i always ask at the start if he is sure they are ready.. he nods i tile.. 🙂

 

[DHTiling]

And not that it makes any difference but he always uncouples as well , no matter what tile goes down..

I have had many chats with him about making sure they are dry but he is the decision maker and follows what Gyvlon rep told him to do drying wise.

 

[jonnyc]

ajax . please enlighten us as to what the advantage is of this type of screed .
you have a raft of experience in this field and i and many others really appreciate your advice as to how to deal with it once it is down.but why should we have to deal with it at all.
one of the advantages i thought it had was that it would dry quicker than sand/cement screed but this is only the case if a boiler is ready to be commisioned and force drying can be carried out.
you and i know that in reality it is very rare scenario.
second advantage could be no expansion joints through doorways and in open area over 40 sq mts. reality i have seen splits in doorways but this could be down to inexperienced screed pourers.
what with the liquid screed accelerators available now, that do not add much cost . these are far more interesting to me

 

[jonnyc]

The test Jonny is to only see if they are at the correct RH.. if you heat a screed at high temps for a long period then IMO there is no damp... the builder dries them and gives the go ahead to tile.. his choice .. but i always ask at the start if he is sure they are ready.. he nods i tile.. 🙂

dave i understand you are only acting on instruction but this is only verbal.
i dont want you to turn work down , but i am trying to warn you that if it does go wrong it will be down to a duty of care and the onus is on you!! this is why i and others are so worried about this system. i cannot stress enough about the danger of tiling on to this screed without someone taking responsibility before the work takes place.
i will not repeat this again but beware.your livelyhood could depend on it

 

[bugs183]

All very good points JonnyC.
I really do want to like these screeds and embrace them, i'm not a Ludite or set in my ways, if it's new and easier to work with then i'm on it 100%,
but, as you say the theory of these screeds is fantastic, yet the reality is far from that.
As you say the screeders are a bloomin nightmare as the are not putting expansion strips in, i can honestly say that EVERY floor of this method has cracks in it.
In my theory as the screeders are pumping more they are getting complacent, they keep messing with the mix to get the floor done.
I've had my one man battle for firm answers on these screeds, and i had given up, but it's good to see someone else trying to get to the bottom of all this!

Our Gyvlon rep has gone very quiet over all of this.

There are far too many things to go wrong here:
The Screeders, over wetting, not putting the expansion strips, not getting the floors flat, not sanding, not educating.
The Moisture testing. Too unreliable, too vague, no training anywhere to help.
The adhesives. I've tried cement based and suitable primers, stuck to the tile, not to the floor. Gypsum based, stuck to the floor, not the tile. GBTA seems to work, but is massively expensive. Uncoupling seems one way, yet Schluter are reluctant to recommend gypsum based adhesives with Ditra.
The builders, not knowing what they are actually dealing with. or just believing the floor is fast track.
The tilers, only a small percentage even know this is a different screed, let alone how they are supposed to be dealt with.
The customer. Thinks the floor will dry quick, it doesn't then as soon as the tiler closes the door behind him cranks up the underfloor heating.

 

[Ajax123]

Around 7 to 8 weeks ago... heating has been on for 4 to 5 weeks... summit like he said 🙂

Just a small point .... It is not a gyvlon ll screed then. It is actually a Francis flower screed....one of mine.

 

[Ajax123]

All very good points JonnyC.
I really do want to like these screeds and embrace them, i'm not a Ludite or set in my ways, if it's new and easier to work with then i'm on it 100%,
but, as you say the theory of these screeds is fantastic, yet the reality is far from that.
As you say the screeders are a bloomin nightmare as the are not putting expansion strips in, i can honestly say that EVERY floor of this method has cracks in it.
In my theory as the screeders are pumping more they are getting complacent, they keep messing with the mix to get the floor done.
I've had my one man battle for firm answers on these screeds, and i had given up, but it's good to see someone else trying to get to the bottom of all this!

Our Gyvlon rep has gone very quiet over all of this.

There are far too many things to go wrong here:
The Screeders, over wetting, not putting the expansion strips, not getting the floors flat, not sanding, not educating.
The Moisture testing. Too unreliable, too vague, no training anywhere to help.
The adhesives. I've tried cement based and suitable primers, stuck to the tile, not to the floor. Gypsum based, stuck to the floor, not the tile. GBTA seems to work, but is massively expensive. Uncoupling seems one way, yet Schluter are reluctant to recommend gypsum based adhesives with Ditra.
The builders, not knowing what they are actually dealing with. or just believing the floor is fast track.
The tilers, only a small percentage even know this is a different screed, let alone how they are supposed to be dealt with.
The customer. Thinks the floor will dry quick, it doesn't then as soon as the tiler closes the door behind him cranks up the underfloor heating.

Cant speak for the Gyvlon rep.... If however you want to give me a call (07966651006) I will be happy to talk you through chapter and verse. That said much of what I have told you will have been outlined in the forums at some point.

 

[Diamond Pool Finishers]

Francis Flower is this you now ajax ? what is your position there then mate ?

 

[DHTiling]

Just a small point .... It is not a gyvlon ll screed then. It is actually a Francis flower screed....one of mine.

How do you know that Alan , did you speak to Dave ?

 

[Ajax123]

How do you know that Alan , did you speak to Dave ?

If it was installed 8weeks ago it will be ours because we supply lafarge in the northeast. We'll be having an official product launch after Christmas. We have been supplying them for some months since tat area decided to move away from gyvlon binder over to Francis Flower who i now work for. Doubt you will notice any difference on the ground. Lafarge themselves have also dropped the "Gyvlon" name and now call it Agila Screed A .... I guess the Gyvlon name will stick for a while ... It was quite a strong brand after all.... I will find out if I am able to publish our data sheets on here for you ....

 

[Ajax123]

Francis Flower is this you now ajax ? what is your position there then mate ?

Yep thats me mate. I am technical and specifications manager doing pretty much the same job as I was before just for a different company. Started 4weeks ago now.....

try this link though .... The website is built

http://www.francisflower.com/