Tiling on Sandy Concrete?

[ILikeDIY]

Concreted a concrete floor to raise it (diluted PVA first, then concrete screed).

Watched videos on Youtube... turns out a "semi-dry" mix is what's used.

Mix a semi-dry mix, pour it down, level etc... last half of the room was a wetter mix (someone else mixed it and added more water than "normal").

Now I'm looking at the floor and the wetter mix half of the room seems fine, but the semi-dry mix half has a gritty sandy texture and feels like you can scrub fine bits off.

How do I tile on this? I'm worried that the tiles might come undone. Thanks.

[ILikeDIY]

Gonna use diluted exterior grade PVA on the concrete then tile over it.

[wine~o]

Do not use PVA as a primer. Use whichever primer it suggests on the bag of adhesive you have.

What adhesive are you using BTW ?

Also this thread really should be in the tiling section. I'll see if I can get it moved.

[ILikeDIY]

Adhesive is Wickes rapid set. Says on the pack it already has primer in it, but I'm not too confident trusting this will penetrate the concrete underneath.

I ended up going to Topps Tiles and asking for the best primer. They gave me BAL acrylic primer which I diluted 1:1 with water and did 2 coats.

Haven't tiled yet but hope this is a good start.