Any info on F BALLS STOPGAP121

[fergal]

We completed a contract about 6 months ago , in which part of the job had a number of GYVLON calcium sulphate floor screeds, now the main contractor has called us back on site because a number of the vinal flooring coverings had started to lift, To make a long story short the screed floor guys have been very fair ,the sanded the floor to remove laitace and recomanded a number of primers,which were passed on to the floor coverings contractor, we have also used the screed guys on two other jobs with out any problems. My question is has any body had any issues when using F BALL STOPGAP121 one coat system on GYVLON screeds, our floor covering contractor who used it, is now claiming that the issue is with moisture in the screed and the F BALL rep is claiming the same. I have done some homework on these screeds and even the screed contractor who layed it claims that all Acrylic primers should be dome with a two coat system 1 to 1 then neat.
Is this correct? I am also dissapointed in the F BALL rep as he seems to want to blame every thing other than his primier, but I found on the F BALL web site a data sheet for the STOPGAP121 and it says its a one coat system Acrylic and everyone else claims that for a proper job it should be two coats...............does any one know which is correct..???:mad2:

 

[kilty55]

hi fergal,i cant answer your question but i know a man who can.if you pm ajax on here thats his territory im sure he will be able to help you

 

[DHTiling]

Do you know if the screed was dry.. what was the RH of the screed.?

 

[Scott]

I think this is one that sandyfloor uses?

 

[Ajax123]

Seen loads of problems with this primer on Gyvlon. 3 things usually spring to mind
1, Excessive moisture leading to emulsification of the primer and sulphate attack on the cement based leveller
2. Lack of penetration into the primer due to inadequate surface preparation (priming dust scenario)
3. Lack of primer penetration due to high viscosity.

Has the primer remained affixed to the surface of the screed or has the leveller come away from the screed with the primer attached to the back of it. This would indicate penetration.

Cost of the acrylic primers I come across need diluting to encourage penetration and this means that 2 coats are often required due to the reduction in polymer content. Bear in mind also that cement and calcium sulphate are not compatible and will not stick together so the primer has to work much harder if you use cement based leveller.

My opinion is that a water based epoxy would be better with a cement based leveller or alternatively avoid chemical incompatibility altogether and use a gypsum based leveller.

I F Ball have technical data to support the use of this primer on a dense anhydrite surface then perhaps they would let you see it. How are they assessing the moisture in order to determine it is too wet. Was there lots of dust on the surface prior to priming. It is up to them really to decide how their primer is to be used.

 

[fergal]

Thanks everyone,

1) The floor screed was checked for moisture by the screed supplier and the floor coverings guy, they both say that it was dry before floor coverings were placed, but as soon as there seemed to be an issue the rep from F BALL said that he thought the screed had moisture in it but only done one test in a total floor area of about 2200m2.

2) The floor was not that dusty before priming started and from what i saw the screed company made a good job of sanding the surface.

3) The F BALL rep told me that they never had any problem like this before, and says it seems to be the screed.

4) The primer was fixed to the back of the leveling compound and in places where you look at the floor you can not see any traces or colour on the screed at all.

5) Ajax123 you say that it up to F BALL to decide how their primier is used, but would be better for LAFARGE GYVLON could list some suitable primers as you say that you have seen a lot of problems with this primers on GYVLON.

 

[Ajax123]

Thanks everyone,

1) The floor screed was checked for moisture by the screed supplier and the floor coverings guy, they both say that it was dry before floor coverings were placed, but as soon as there seemed to be an issue the rep from F BALL said that he thought the screed had moisture in it but only done one test in a total floor area of about 2200m2. How was it tested. If both parties have tested and the results are replicable then they can be trusted.


2) The floor was not that dusty before priming started and from what i saw the screed company made a good job of sanding the surface. Sounds good

3) The F BALL rep told me that they never had any problem like this before, and says it seems to be the screed. Do you want a list

4) The primer was fixed to the back of the leveling compound and in places where you look at the floor you can not see any traces or colour on the screed at all. That tells me that the primer has failed to penetrate the surface of the screed. This would normally be because the screed is either very dusty which you say it was not or that the primer has failed to penetrate the surface of the screed due to high viscosity. The latter would be my natural conclusion. If the primer has not penetrated the screed then it cannot hang on to the screed in any way. This would lead to the floor failing. It would normally indicate an ettringite reaction although it is possible. The primer being of a relatively high polymer content and viscosity it would often need to be diluted before application. As I said

5) Ajax123 you say that it up to F BALL to decide how their primier is used, but would be better for LAFARGE GYVLON could list some suitable primers as you say that you have seen a lot of problems with this primers on GYVLON.

As Lafarge Gyvlon do not make primers it would be innapropriate for them to specify materials for specific applications. Additinoally some applications require different primers than others and Lafarge Gyvlon do not necessarily have the expertise to decide which is appropriate for which application. Additionally Primer manufacturers change their primer formulations so what might be suitable today might not be tomorrow. You can see that there are quite a few reasons why Gyvlon don't specify primers. What I am happy to do as part of my work is to recomend different generic primer types to people based on the knowledge I do have (which at pain of sounding big headed is not inconsiderable). I would then give you contact details of the relevent expert at manufacturers of such primers. I do the same with levelling/smoothing compounds and tile adhesives as well.

 

[The Legend; Phil Hobson RIP]

Hi and:welcome:

 

[White Room]

Hi and welcome

 

[SandyFloor]

I think this is one that sandyfloor uses?

I usually use Stopgap P131 (neoprene) for concrete. P121 is the acrylic one suitable for Gyvlon. I've used other acrylic primers on gyvlon prior to tiling and found you really need to work it in when applying it neat.

 

[Prem Tiler]

Welcome to the forum.