One for Ajax!

[trevortine]

Just looking for advice on what's the preferred choice of adhesive on Lafarge screeds these days? Got one to do in a few weeks and when quoting last weekend the site agent was quick to tell me about problems they have had with previous customers having tiling done on these. Thanks in advance chaps!

 

[DHTiling]

The preferred choice for any anhydrite screed supplier would be gypsum based ... but that does not mean you have to use a gypsum based adhesive...

1: Are you sure it is gyvlon screed.?

2: Some previous lafarge areas are now F.flowers version called Gypsol..

3: Is the screed heated , this can aid on the drying process

4: how long has the screed been down..

 

[trevortine]

The preferred choice for any anhydrite screed supplier would be gypsum based ... but that does not mean you have to use a gypsum based adhesive...

1: Are you sure it is gyvlon screed.?

2: Some previous lafarge areas are now F.flowers version called Gypsol..

3: Is the screed heated , this can aid on the drying process

4: how long has the screed been down..

As far as I'm aware this is relatively new in this area, all I know is what the site agent said and that was that its a Lafarge self levelling screed. The screed isn't heated and has been down for approx two months.

 

[DHTiling]

Ok.. it will be gyvlon and poss LL version.. now 2 months is a short time at this time of the year... you need to invest in a Hair hygrometer and test to see what the RH% of the floor is at present..

 

[Ajax123]

Just looking for advice on what's the preferred choice of adhesive on Lafarge screeds these days? Got one to do in a few weeks and when quoting last weekend the site agent was quick to tell me about problems they have had with previous customers having tiling done on these. Thanks in advance chaps!

Aah. Well now. I am no longer in a position to talk about Lafarge screeds as I do not supply them so you would have to ask them directly for recommendations on their specific screeds.

In terms of my recommendations for generic anhydrite of or Gypsol screeds in particular I would always recommend in the first instance. A gypsum based adhesive of which there are several in the market. If there are technical reasons why a gypsum adhesive should not be used I wold go for a gypsum compatible one such as kreakoll h40 ideal or benfergyps. If these are not suited to the specific application (I cannot think why they wold not) then I guess I would have to say cement over epoxy primer. My last suggestion would be a cement based adhesive on an acrylic primer.... This is the combination tha I see by far the most issues with.

Preparation is the key to success though.

East Kilbride could well be a Gypsol screed ... If you can find out who actually supplied it I could tell you for sure. I can also tell you that two months is right on the edge of being suitably dry assuming it is 50mm as the drying is dependent on depth which is at 1mm per day to 40mm and 2days per mm thereover so 50mm is 60days I.e. 2months. The heating must be commissioned and run to temperature so if this has not been done it must be prior to tiling and I would anticipate that this would leave the screed fully dry. A simple moisture test with a hygrometer or carbide bomb can determine this.

 

[trevortine]

Thanks very much for replies chaps. The area is actually Cambuslang and its a new built Taylor wimpey house. This I the first I've came across in this area although I fear that I may have been mistaken in the past. I always prime beforehand so maybe previous work will be fine, certainly not heard anything from these jobs. After speaking to bal technical they are saying that priming with neat apd and then using SPF or RSF is suffice. Would you agree? This is the previous route I hav taken although primer was a 2:1 sbr (assuming the screed was sand/cement) No heating on this one, I will do a simple moisture test and see how it looks then if showing signs of moisture will invest in hair hydgrometer. Don't want to take any chances!

 

[DHTiling]

A sweat test is the easiest method but not as accurate as a hair hygrometer... normal damp meter will measure surface damp and not what is down say 40mm+

 

[trevortine]

A sweat test is the easiest method but not as accurate as a hair hygrometer... normal damp meter will measure surface damp and not what is down say 40mm+

do you have one Dave an if so where's best to buy?

 

[DHTiling]

F.Ball and co... sell them.. an unheated screed is the longest to get dry..

 

[DHTiling]

Just had a thought... you say lafarge.. are you sure it isn't the Agila screed.. ?

 

[trevortine]

Just had a thought... you say lafarge.. are you sure it isn't the Agila screed.. ?

I'm gonna have to go back and check this out, all I was told was Lafarge.

 

[DHTiling]

Lafarge do 2 types... gyvlon is anhydrite and Agila is cement based, both are pourable screeds..

 

[trevortine]

Hopefully find out by the end of weekend, job ain't for bout three weeks anyway and is gonna depend on moisture content ( if applicable) whether it gets done or not. Cheers for the heads up, plenty experience in most areas except this one, everydays a learner!!

 

[Ajax123]

Good spot Dave. Yes could easily be agilia and not Gyvlon.

 

[DHTiling]

It sure is , fingers crossed it is Agila ... quicker to progress then.

 

[Mark S]

Lafarge Agilia range covers, Screed A, Gyvlon and Horizontal a flowing 10mm aggregate screed, the Horizontal would generally be installed at 75mm.
I would check with Lafarge which Agilia products it is, and we can then best advise on the way forward.

 

[bugs183]

Hiya.
Don't forget these screeds will need sanding, that needs to go into the price.
I saw a Horizontal screed being poured then waxed, then builder was convinced it would need no prep work, when i asked him about the wax and how he was going to remove it, he had no idea!
As the guys say homework is key for these screeds, don't rely on the builder.
If it's of any help i've used both H40 and GBTA adhesives and the H40 feels much like a single part flexible adhesive in consistancy and use, but i can't say i was inspired with how it stuck. The GBTA is weird at first to work with, more like a pourable thick bed feel to it, took a good while to get the mixes consistant, either too runny or just too stiff, but once i got used to it it was fine to use, and i felt more confident in how it actually stuck. It's bloomin expensive though!

 

[Ajax123]

Yes the agilia screeds (apart from the anhydrite) will be sprayed with a curing agent. This is often waxy and will require removal. Also a moisture test is essential because the wax is designed to keep the moisture in the screed (hence curing). It may be that it needs further drying once the curing agent is removed.

 

[Mark S]

The newer Agilia range has a 'built in' curing agent, so may not have been sprayed, but the screed should still be sanded and prepared in the 'correct' manner.
I have heard a few people mention the GBTA addy is strange at first till you get used to it, not heard much re the H40 not sticking well, was there a particular tile type that was on?

 

[bugs183]

I used it with stone and porcelain Mark.
I'm not saying it was no good, it just didn't make me go bloomin 'eck that's stuck!
But you do find these days that the adhesive will either stick to the substrate well and the tile will come away clean, and for other adhesives the opposite. You rarely see it as you often used to pre porcelain days where everything had just stuck in one lump!

 

[Mark S]

I know Kerakoll are doing an open evening in Leeds next wed night at Wheatwood Hall, where they are demonstrating a few products, with H40 being one of them, maybe some members would like to go along and ask some questions.