Is there a visual difference between the different types of screed - Tile Advice

[RWoods]

My new laid screed floor has been down for 4 months and from reading up I probably need to seal it prior to tiling.

Unfortunately I cannot get hold of the builder to find out whether it was a cement screed or flow/anhydrite type screed. Is there a visual way to tell (ie color/finish) that would let me know what was used?.

Or is there some kind of universal sealer that would work with either type.

I have been recommended Kerakoll Biogel for the adhesive if that makes a difference and the tiles are wood effect 120x20 porcelain.

 

[hmtiling]

Post some pictures of the screed.
Have you checked how level it is? If it's perfectly level chances are it's anhydrite

 

[Dumbo]

Post some pictures of the screed.
Have you checked how level it is? If it's perfectly level chances are it's anhydrite

Only if you know who did it
I've been to a couple of dodgy ones

 

[Cranbrook]

Personally, If your floor has been down 4 months and its anhydrite, I would not tile straight on to it, even if you seal it. I would be hiring something like the following,
HIRE GRINDER FOR AN-HYDRATE FLOOR OUTSIDE 7 DAY PERIOD - WH Surface Preparation UK ltd - https://www.wh-surfacepreparation.co.uk/hire-grinder-for-an-hydrate-floor-outside-7-day-period/155
whilst not cheap, is phenomenal at what its for, and will be much much quicker than any other way of sanding/grinding back the surface

 

[RWoods]

pics attached. It looks pretty level throughtout.

 

[jimthetiler]

that looks like a sand and cement screed.

 

[Dumbo]

Sand and cement .

 

[hmtiling]

As above

 

[RWoods]

So without having to trawl the forums i've 100sqm to seal. Whats recommended for sealing and how long do I have to leave it after?. I plan to use an Idrobuild Tex anti crack mat inbetween tiles and screed and from what Ive seen PVA is a nono.
Cheers for the help its much appreciated

 

[Dumbo]

Mapei primer g is good . 2 coats you will need at least 10 litres . Follow directions on can

 

[RWoods]

Excellent cheers

 

[RWoods]

Bugger I can't find the time to tile myself. Thought I could swing it with the wife but it's not happening with the new baby.
I have a tiler I can use and was going to just get the Kerakoll Biogel no limits for him. If he's never used this before would it be safer to just get some flexible tile adhesive or should it just pretty much be the same. He says he can use whatever adhesive I supply. Any advice appreciated. The only reason I was going the Kerakoll way was the shop I bought the tiles from recommended it.
Cheers