Mapei primer G skinned over

[Hoot37]

Hi,
I've previously posted in this forum about my first failed tiling attempt. I was able to take up the tiles easily after they'd set and someone suggested my primer may have skinned over.

Since then I've taken up all the adhesive and primer and have primed again with mapei primer g 1:1 and it has skinned over as you can see from my picture. You can also see that it looks like there are two different types of material on the floor. The material closer to me is slightly higher than the material that the primer is peeling off. I don't have a clue what the screed is and am wondering if that might be my problem.

My intention is to level the floor with mapei ultraplan self leveler.

 

[Dan]

You seem to have some backing from some underlay or chord carpet there.

Have you rang Mapei Tech line to speak to somebody there? - They're awesome guys. Mention Dan sent you from the forum and they'll help you out as best they can.

Sounds like you might need to mechanically move whatever it is that's on your floor. Get right back to the actual surface to tile to.

You can use sanders and grinders and perhaps even a SDS to hammer away at it, create some scores for the primer to adhere into.

That all said, I'm not a tiler. So speak to Mapei for me. 🙂

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[Dave]

Your ratio is too strong. It wants to be 4:1(water to primer).
An orbital sander with 60 grit will help remove any crap on the floor.

 

[Hoot37]

Thank you both. Do you think this may be an anhydrite screed?

 

[Dave]

Thank you both. Do you think this may be an anhydrite screed?

is it a pourable screed ?
Is it heated ?
Sand a section of screed and tell us what colour it is.

 

[Hoot37]

Not sure if pourable. It's been down since the house was built 12 years ago. It's not heated.
Ive just sanded a patch and it's a white /light grey and is rough after sanding.
I'm going to sand the whole floor back today.

 

[Dave]

If its grey , then it isnt anhydrite , make sure you water the primer down more and it’s won’t skin.

 

[Hoot37]

If its grey , then it isnt anhydrite , make sure you water the primer down more and it’s won’t skin.

Excellent, thank you! I'll be sure to post an update.

 

[Hoot37]

So I've spent over an hour sanding the floor back. Would I only need one application of the primer 4:1 or would it need multiple applications?

 

[Hoot37]

I've made 3 applications of the primer mixed 4:1 I haven't applied it very thick, just enough so I can see the floor is wet where I've applied it.
Should I leave it there or apply more? I'm not sure how much is enough and I don't want it to skin over again.