Has all my Laitance been removed??

[Ashah12]

If you are not sure sand it again? It's you that needs to be comfortable that its properly prepped. I can say there is some small, patches of what looks like flaky laitance there but whether its enough to cause you an issue I dont know from photos.

Are those small patches of laitance the lighter shades of the floor?

 

[Ajax123]

Yes

 

[Ajax123]

The only test I've done is laying a dpm on the floor with planks of wood on either side to weigh it down and checked if theres any condensation underneath 24 hrs later

Then you need a proper test. Are you DIY tiling or getting a contractor in

 

[Ashah12]

Then you need a proper test. Are you DIY tiling or getting a contractor in

Getting a contractor in

 

[Ashah12]

Then you need a proper test. Are you DIY tiling or getting a contractor in

How do I go about getting it properly tested?
I have a humidity reader which measured relative humidity at 30% when I had the ufh on. Does that say anything?

 

[Ajax123]

then the contractor should be able to verify moisture and should not start til its right.

 

[Ajax123]

How do I go about getting it properly tested?
I have a humidity reader which measured relative humidity at 30% when I had the ufh on. Does that say anything?

yes it does... without wishing to be in any way harsh - it tells me that you don't know what you are looking at. to be dry the screed needs to be below 0.5% moisture or 75% RH. when it was made in the factory it had perhaps 13% moisture so your 30% is clearly wrong.

 

[Ashah12]

yes it does... without wishing to be in any way harsh - it tells me that you don't know what you are looking at. to be dry the screed needs to be below 0.5% moisture or 75% RH. when it was made in the factory it had perhaps 13% moisture so your 30% is clearly wrong.

The 30% was the RH in the room once the ufh was running and when ufh was turned off the RH crept upto 60% and has been consistent at that figure. When using anhyfix adhesive isnt the figure 85% RH? I maybe wrong.

 

[Ashah12]

Update...had someone come out to sand down the floor again. He used a diamond disc sander. I've hoovered all the muck but I'm still getting patches that are stuck to the floor (definitely not loose) of what I think is laitance on the floor?? Is there enough on there to fail the floor? Or am I overthinking?

 

[Ajax123]

If they’re not loose they’re fine