Extension floor tiles - Tile Advice

[Mitch88]

Hello fellas,

New to this forum thought I'd get some opinions on my method as I've never dealt with tiling over gypsum liquid screed. I also have wet underfloor heating over 40m2. The screed was laid 4 weeks ago after 9 days I sanded the laitence off and primed with Weber. My plan is to use gypsum based adhesive 3mm notched for applying database matting then Mapei rapid set flexi for my 60x60 porcelain tiles. If there' any advice you guys would like to chuck in please let me know I'm planning on getting the database down this week

Thanks in advance
Mitch

 

[Old Mod]

Hi and welcome to the forum Mitch.

Yes, definitely get screed moisture levels checked properly.
If that screed is damp when you fix anything to it, it will fail.
Seen a lot of it lately where they’ve still been damp. They have not faired well at all.
Make sure ufh is commissioned first.

 

[Mitch88]

Thanks for a swift reply 3fall

Ufh is commssioned and running problem is the weather isn' helping it being on at the moment as the thermostat is shutting it off. What' the best way of checking the moisture levels?

 

[Old Mod]

. What' the best way of checking the moisture levels?

Check with your adhesive manufacturer, they may well offer a service, some do.

Failing that, ideally 2-3 Hair Hygrometers in various places or one used in several locations.
With readings taken every 12 hrs or so over two days. Again check with adhesive company what reading they require.
Anhydride is lower than sand and cement.

Something like this