primer peeling

[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

 

[kilty55]

hi chequers,on a posoitive note at least you have found this out at start of the floors and not done the entire job so thats a bonus mate,

as above the primer doesnt seem to have done its part and advice from the company seems wrong imo from what you have said......personally i wouldnt use that primer or addy for the job based on whats just happened cant you argue the case with the shop to do a swap

 

[Ajax123]

No thank you

But it sticks tiles to gypsum based screeds so why not??

 

[Mike Mike]

Any way that would not make much difference cos they are only one of many suppliers...... And in this case it is a bit unjust cos cemex supplied the screed not lafarge.....

I didn't read all of the posts, so missed that it was Cemex. I can suggest burning down Cemex's HQ instead. In fact, here we are very Anticemex, LOL Välkommen till Anticimex - Anticimex

Ajax, you seem to know an awful lot about anhydrite screeds. Serious question here. What is the point of them? Seriously? What benefits, and advantages, if any, are there with calcium sulphate screeds vs calcium aluminate cement based SLC?

 

[The D]

But it sticks tiles to gypsum based screeds so why not??

I do not like being a gin pig and then blamed when it all goes wrong. There are a lot of threads on this subject and not many that have not had problems weather it be the tiler was told to sweep the floor with a stiff brush and no need to sand to remove the laitance or whatever you would like to call it today. (or do we have to sand with 80 grit??) or it could be the tiler has not applied sufficient primer or the tiler has over applied the primer or it is the wrong type of primer or it is a different type of anhydrite or we should be using gypsum adhesives. Anyway whatever I a staying away from them for now and we will see what problems the future holds for the poor old tilers that get involved .

 

[chequers]

I do not like being a gin pig and then blamed when it all goes wrong. There are a lot of threads on this subject and not many that have not had problems weather it be the tiler was told to sweep the floor with a stiff brush and no need to sand to remove the laitance or whatever you would like to call it today. (or do we have to sand with 80 grit??) or it could be the tiler has not applied sufficient primer or the tiler has over applied the primer or it is the wrong type of primer or it is a different type of anhydrite or we should be using gypsum adhesives. Anyway whatever I a staying away from them for now and we will see what problems the future holds for the poor old tilers that get involved .

Hi
Will try and post some photos ,ajax you are correct it is cemex supaflo ,i am in south wales ,will speak to cemex later

 

[doug boardley]

what ratio did you dilute the PR360 Chequers? I know on the tub it says between 3 and 5 parts water to 1 part primer.

 

[Time's Ran Out]

He used it 4:1 Doug. But I'am assuming that that is not 4 parts primer : 1 part water.

 

[chequers]

He used it 4:1 Doug. But I'am assuming that that is not 4 parts primer : 1 part water.

To confirm I mixed 4 parts water 1 part primer I had checked with their tech many times to make sure there were no mistakes . I was told that to have enough primer to give two coats I would need 45 kilos of pr360 but I have used about 8 kilos at 4 to 1

 

[chequers]

To confirm I mixed 4 parts water 1 part primer I had checked with their tech many times to make sure there were no mistakes . I was told that to have enough primer to give two coats I would need 45 kilos of pr360 but I have used about 8 kilos at 4 to 1

weber came down today with a 4 to 1 Pr 360 which they applied to test area after sanding clean ,i then applied a 4 to 1 of my pr360 next to it ,this evening to the eye they are not the same colour although still drying ,the weber 4 to 1 is fine but my 4 to 1 is if you put your fingernail on it is peeling.Same product ,same mix but both not working the same ?

I,m told that the Supaflo should have been mechanically sanded but cemex told me not to but in any event having seen the test area sanded and it is still peeling ?

I do wish i had gone with as different primer ,in fact we have done a test area on a no sanded patch with norcross and it is fine

Dont know where this is heading but how would you remove all this primer ,tried with a orbital 80 grit and it would take years .
Is there a machine out there ?
Ajax i have tried phoning ,will try you Monday
Thanks

 

[Ajax123]

Sorry mate I been away for a few days. Back on Monday though so will comment then if that is ok.

 

[Mike Mike]

weber came down today with a 4 to 1 Pr 360 which they applied to test area after sanding clean ,i then applied a 4 to 1 of my pr360 next to it ,this evening to the eye they are not the same colour although still drying ,the weber 4 to 1 is fine but my 4 to 1 is if you put your fingernail on it is peeling.Same product ,same mix but both not working the same ?

I,m told that the Supaflo should have been mechanically sanded but cemex told me not to but in any event having seen the test area sanded and it is still peeling ?

I do wish i had gone with as different primer ,in fact we have done a test area on a no sanded patch with norcross and it is fine

Dont know where this is heading but how would you remove all this primer ,tried with a orbital 80 grit and it would take years .
Is there a machine out there ?
Ajax i have tried phoning ,will try you Monday
Thanks

Yes. Try one of these (or similar). HSS Hire - Commercial Floor Finishing Sander Hire and Rent

Talk to them about what discs they have available. Forget sandpaper for this application. You want a disc with 5 or 6 stone cups on it to really grind the top layer of the screed off. Can't remember how big an area you have, but you will be able to completely sand a couple of hundred m2 in a morning with one of these.

 

[Alan M]

sorry m8 for the dose you have on your hands.
presumably given that your bottle isnt doing what theirs is you will get compensated for it.

as for removing the primer. (worth asking webber if they have a primer remover)
by the sounds of it , it is like a solid layer on top of the floor.
i would get one of those scrapers for wall paper that are really flexable and try and get in under it.
if that wont work you will have to sand it off, maybe one of those sanders for wooden floors would speed up the removal.
i would guess that that primer would clog the abrasive fairly fast.
do you know anyone with a festool rotex sander . they have great sandpapers for sanding stone and paint etc(saphire ,granat ,or crystal should work) and with vac very little dust (almost none)

 

[Mike Mike]

weber came down today with a 4 to 1 Pr 360 which they applied to test area after sanding clean ,i then applied a 4 to 1 of my pr360 next to it ,this evening to the eye they are not the same colour although still drying ,the weber 4 to 1 is fine but my 4 to 1 is if you put your fingernail on it is peeling.Same product ,same mix but both not working the same ?

I,m told that the Supaflo should have been mechanically sanded but cemex told me not to but in any event having seen the test area sanded and it is still peeling ?

I do wish i had gone with as different primer ,in fact we have done a test area on a no sanded patch with norcross and it is fine

Dont know where this is heading but how would you remove all this primer ,tried with a orbital 80 grit and it would take years .
Is there a machine out there ?
Ajax i have tried phoning ,will try you Monday
Thanks

This I think is the most popular brand and model in the U.K. http://www.spe-int.com/multipurpose...purpose-preparation-system.aspx?prid=19&cid=4

Here's one for sale. SPE STR701 Multi Purpose Floor Preparation Machine | eBay

The special drive board you need is abou £150 ish. Everyone should have a rotary floor machine in their tool kit, use it on all freshly poured screeds to get a good key.

There are cheaper ones, Numatic do some, but don't know about accessory drive boards, but you could ask them. You see them for sale for a couple of hundred quid every now and then. I use Janser and Nilfisk for sanding all floors before tiling / floor laying. LOL, the ONLY application they are NOT used for is sanding wooden floors, so ironic that HSS call it a wooden floor sander?? Oh well...

 

[chequers]

This I think is the most popular brand and model in the U.K. http://www.spe-int.com/multipurpose...purpose-preparation-system.aspx?prid=19&cid=4

Here's one for sale. SPE STR701 Multi Purpose Floor Preparation Machine | eBay

The special drive board you need is abou £150 ish. Everyone should have a rotary floor machine in their tool kit, use it on all freshly poured screeds to get a good key.

There are cheaper ones, Numatic do some, but don't know about accessory drive boards, but you could ask them. You see them for sale for a couple of hundred quid every now and then. I use Janser and Nilfisk for sanding all floors before tiling / floor laying. LOL, the ONLY application they are NOT used for is sanding wooden floors, so ironic that HSS call it a wooden floor sander?? Oh well...

Just spent two days sanding with a standard floor sander i managed to get from the local hire shop before they closed ,the p24 grit is getting it off but anything higher no chance .
It is a hellish job with lost of dust
I would like to say a big thank you to everyone who has contributed to this posting ,it is very much appreciated .
Once it is all off i dont know about reapplying the Pr360,when webber came down on Fri they said the surface should not be shiney but their test sample area is! .
I am wondering about what Primer to use that is the best , i had looked long at the eco prim and the Super G ,but i have done a test patch of the Norcross Prime bond which is a form of SBR and that seemed Ok .
This has been a nightmare job but better than the tiles failing

 

[bugs183]

Well done Chequers for keeping your cool and doing this job properly, most would say damn it we've started it'll be alright!!.

These screeds are causing so many people problems, which is a real shame as they are so nice to work on. I've been recommending them to builders and so far have had no problems, i've been sanding and priming them with a dilute epoxy epoxy primer and that stuff doesn't shift, but i'm waiting now for someone to say you can't use that because it contains some new ..ide chemical that will react with it.
I will be swapping to the gypsum based adhesives on the next jobs as this is the direction that these floors dictate.
Once again Ajax has been an amazing help, with well thought out and well written guidance on these matters, he's being a bit of a hero on hero on here.
Good luck matey!

 

[Ajax123]

Well done Chequers for keeping your cool and doing this job properly, most would say damn it we've started it'll be alright!!.

These screeds are causing so many people problems, which is a real shame as they are so nice to work on. I've been recommending them to builders and so far have had no problems, i've been sanding and priming them with a dilute epoxy epoxy primer and that stuff doesn't shift, but i'm waiting now for someone to say you can't use that because it contains some new ..ide chemical that will react with it.
I will be swapping to the gypsum based adhesives on the next jobs as this is the direction that these floors dictate.
Once again Ajax has been an amazing help, with well thought out and well written guidance on these matters, he's being a bit of a hero on hero on here.
Good luck matey!

No pressure there then....

Sorry I mised your posts at the weekend. For future reference I think you would have been better to use a sot blasting machine to remove theprimer. Would have been much quicker and cleaner. However that bit sounds likeit is done now.
I guess the advent of primer less systems to go on anhydrite is a real bonus when you see stories like this.

What you doing regarding restocking the tiles. If it were me I wold deffo go with a primerless adhesive.

 

[Jamiewh]

I’ve had a similar problem. I levelled my hallway using no nonsense floor screed. Then I primed it Bostik Cempolay Universal Primer Blue Pigment 2.5Ltr to get it ready for tilling but in a few areas, the primer has peeled off?