Drying screeded floor

Week per inch thick I *think* - if the air is warm - at least for a wet lay.

Partly depends how wet/dry the screed was. Might be somewhat less for a proper dry laid screed.

Once it is cured, you can accelerate the process by closing the room up and running a dehumidifier. If you have a cheapo damp meter you can keep a check on progress. (The sort with two spikes you stick in). Even so,likely to take a couple of weeks. Room must be airtight and avoid opening door sexcept to remove water tray from dehumidifier.

This is usually left until all "wet trade" work is done so that the whole room can be dried out at once.

Yes, Plasterers are plastering as I type (Wednesday), and a second de-humidifier has been hired for Friday when the 5 cu M of screed go down. (50 sq M area) - the screed will have fibres in it to hopefully prevent too much drying out cracking.

AWEM

Frankly don't wait period. The tiling process puts massive amounts of wet into the screed.

Try to NOT use the UFH at high temps until the thing has dried out a bit.

And wait before you grout.

Some boilers/control systems (e.g. Vaillant) have screed drying programs, that warm that zone slowly and progressively following a program of warmer and cooler heating sessions over a month to accelerate the process.