hi,

Got a job coming up anhydrite screed, Can someone recommend a gypsum based adhesive for it and where i can get it from im down in swansea i tried one local tile shop that sells benfer adhesive but they couldnt get hold of benfergyp.

any advice much appreciated

ted

pm Ajax and he should be able to rattle some names off for you

You can get:

Weber.col at CTD
GBTA from Creative Impressions

and a Gypsum friendly adhesive from kerakoll called H40 ideal

My local supplier in Derby called Tile Town had some in the other day. Bit of a trek from Swansea but I think they do a delivery service.

Could also try Forbo Flooring - Alphycol 725

thanks for all the help gents what would i do without the forums.

ted

Originally Posted by tedley34

thanks for all the help gents what would i do without the forums.

ted

use the wrong glue probably......

got to say thankyou to bill from kerakoll with giving me a contact for their adhesive down my way. cant fault you mate.

ted

Are you going to use a membrane with it ted..?..

wasnt going to dave would you recommend it? tiles that are going down are porcelain if it was a stone tile i wouldnt lay them without ditra or durabase ci.

ted

All i can say is i tried Ideal h40 and it didn't stick to the membrane at all..

Also it is a very slow setting adhesive.. So no primer and hopefully you will be ok, but me.. not using it anymore..

thats a worry dave. so when the adhesive was dry you could peel the membrane away?

Yep.. Adhesive stuck to the substrate but not the membrane

The stuff at Tile Town in Berby was Weber Col Anhydrite. A true gypsum based adhesive. Also Creative impressions GBTA from Preston. They deffo do a delivery service. I can sort you numbers if you need them.

well i cant see myself using it then if it cant stick to the fleece of the membrane id be haveing sleepless nights worrying about the tiles. weber it is then?

ted

Not sure how easy it will be to get the weber stuff but if you give them a call and speak to Mark Birch. Tell him you been speaking to Alan at Lafarge. If you struggle with them speak to Creative Impressions.

Norcross are also looking to develop their Unique product for floors as well. Not much use to you in the immediate term but will be another to add to the list.

Any failures with any of these other adhesives alan?

I have not seen any failures with the creative impressions stuff. That has been around for at least 5 years. Dexters made the same gear before that (sadly they went bust) never saw any issues with that one either.

Only seen the weber gear used once in the UK and it has gone fantastic. They sell tonnes of it in France. My counterparts in France have been "encouraging" the use of gypsum based adhesives in Europe for several years. They used to get loads of failures just like us over here. When people started to use Gypsum the failures pretty much dissapeared. Not saying there have been no failures - i guess there must have been some - I am not aware of any though.

The only thing I get fed back to me on the gypsum addys is that the open life on the floor is quite short....pot life typically 45 minutes and don't spread any more than you can lay tiles in about 10 to 15 minutes. In other words you have to work quick and clean.

They even use Gypsum Based adhesive on these screeds in Turkey FFS....

But.. Alan.. what is the recommend when using these Gypsum adhesives in bathrooms.. area's that might be subject to wetting.. It is worth mentioning in this thread as some might not be attending the Gyvlon training day soon.. I know but ted might not and maybe a few others..

The recomendations are that the adhesive should not be used in areas where it can become wet. The same recomendation is made about anhydrite screeds. The key issue here is areas where it "can become wet". From the screeds point of view this means that it must be covered with a water proof covering e.g. a vynil, tile, tanking membrane etc. My general recomendation for normal bathrooms would be to use a tanking system or a liquid DPM to protect the screed from becoming wet. you would then be able to use a cement based adhesive. Wet rooms are usually laid to falls and so ahnydrite would not normally be used here. If a tanking membrane is not to be used then you would have to rely on the grout joints being sealed. This is the reason I do not like to see Gyvlon used in communal shower areas where the floor covering is tiles. All that said I have seen loads of bathrooms tiled over Gyvlon without issue. I am going to be badgering Sab at creative impressions over the next few days to see how he feels about the bathroom scenario.

Yepp.. i like to use a membrane, hence why i also used one on the floor i mentioned above..

Whilst we have you mate.. Just to mention another issue members might not be aware of.. Isn't it also a no no to use a tanking solution kit on a heated Gyvlon screed... so best to use a membrane.

so no need to tank a kitchen/ utility floor then?

I'm gonna need a larger note pad on the 25th

I would not be tanking the kitchen or the utility.

The rules on using DPM's on Gyvlon screeds are that the screed should be unheated, below 87%RH (1.5% moisture) and at least 28 days old. NOw these rules have been set up based on the testing that Lafarge Gyvlon have carried out on their screed. I am not aware of any other manufacturers who have done this work so as far as I am concerned it applies to Gyvlon only. The rules are designed to take account of the fact that floor coverings often have to go down before the screed is dry. i.e. to entrap the residual moisture.

The need for a DPM is largely irrelevent on a heated screed because the heating can be used to force dry the screed pretty dashed quickly so there would be no need to use a DPM to suppress the residual moisture.

However if the screed is dry i.e. below 75% RH (0.5% moisture) then the use of a tanking membrane would be ok regardless of whether the screed is heated or not. Indeed I always suggest to main contractors using the gear in commercial kitchens that they dry the screed and then apply a DPM. This is not to trap moisture in the screed but to keep it out. It would become a floor covering in its own right effectively.

Clear as mud I guess.......

Originally Posted by doug boardley

I'm gonna need a larger note pad on the 25th

...A3 pad at least......make sure you come with some easy questions as well though........pleeease

going to order the gbta from creative impressions noticed they have a primer would you use this dave, alan, and do i still need to sand the screed using this adhesive?

ted

If the screed has surface dirt etc from builders then yes sand.. but it is wise to sand anyway,, easier for the primer to key then..

thanks dave much appreciated. do you have link for a guide on tiling onto anhydrite floors just to make sure ive done all the necessary, moisture readings and commisssioning heating etc...

ted

Try these..

Help preparing an anhydrite surface

Anhydrite sceed

gyvlon screed



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