primer peeling

[Time's Ran Out]

For my sixpenny worth it sounds as though the primer coats are too thick and you have a skin on the surface, and there is still too much loose material on the surface of the screed.

 

[chequers]

I used a 4 to one ratio which is what i was advised by weber and what it says on the back of the bottle

I am currently taking up all the tiles ,cant really descrieb how i am feeling when i have done everything as how you should do it and i am in this position .

 

[Andy Allen]

how did you sand the floor, what grit paper did you use..

 

[chequers]

how did you sand the floor, what grit paper did you use..

I handsanded with 80 grit in accordance with what cemex said you could do which was not mechanically abrade
Ta

 

[The D]

I am at the moment turning down all floors that are on to anhydrite as I just do not trust the adhesion to this sub floor. I have sanded and primed so many floors and I have on occasion had to change a tile for whatever reason and it is always the same with the floors that are anhydrite. I brake the tile out and I can get the adhesive of the floor with very little effort. I understand that my opinion may not be very popular but it is what it is.

 

[Ajax123]

Why not change the dhesive that you use to one made from gypsum...

 

[Ajax123]

Am I beating my head against the wall. The primer is simply sat on top of the screed. It has not penetrated. This is irrelevant to the Rate of dilution. The primer should be stuck to the screed. If it is not then how in the world do you expect the adhesive to hold the tiles down. You might as well put a polythene bag on the floor and tile on that. In order to get a primer to penetrate an anhydrite screed it should be abraded with typically a sixty grit or coarser paper. 80 grit is not good enough.

Cemex screed is not anhydrite unless you are in Ireland. If you are in Ireland you are not using skin free screed so mechanical abrasion is generally the thing to do followed by a blooming good vaccuum. You say the other houses are ALS peeling. This could be for the same reason or there could be three entirel different reasons as they have al been done differently. More primer coats won't make the first one stick to the floor any better. Use a primer less system.

 

[chequers]

Why not change the dhesive that you use to one made from gypsum...

Hi Ajax and all
I cannot change adhesives as i have already purchased Weber set and ad250 two part for the floors .
The problem now is to how to get this primer off and get back to the start line .
Any ideas lads , what primer i should i go back on with then .I am glad for your help because without what you have advised me i prob would have been in a far worse position further down the road

 

[Ajax123]

if you want to give me a shout tomorrow on my mobile 07545932723 I will talk you through a few options. That will give me time to have a think.

it is Cemex S assuming you are not in Ireland it will be a hemi hydrate rather than anhydrite. hemi hydrates contain citrates which anhydrites do not so I will have a think about if this affects the pr360 and how it penetrates into the screed. I am very confident though that if the primer is simply peeling off it will needto come up. My first thought is to change the primer as I appreciate your issue with changing the adhesive. Let me think on it nd ring me tomorrow if you can.

 

[The D]

Why not change the dhesive that you use to one made from gypsum...

No thank you