Electric UFH on solid floor

[TeaAndBiscuits]

Hi all, as part of my bathroom refurb, I want to install electric UFH.

The floor of my bathroom (approx 3m x 4m) has a concrete sub base, then 75mm of jablite insulation, topped with about 75mm of screed.

The bathroom will have a large (>2000BTU) plumbed (and electric) towel rail so the UFH wouldn't be the primary heating for the room. It's just to take the chill out of the tiled floor for when you are in there barefoot.

Will a system such as 'warmup' loose wire system be effective here just embedded in the tile adhesive? I don't want to use insulation boards on top of the screed as I don't have the floor height for that.

One electrician I asked said that the electric system will need to basically be on constantly, with the timer just varying the power level.

Also, this is going to be a semi-wetroom type bathroom (walk in shower with glass panels but no tray) so I plan to tank it with a solid membrane, if that makes any difference.

Cheers

 

[flameport]

One electrician I asked said that the electric system will need to basically be on constantly, with the timer just varying the power level.

They are correct.
With it directly on the screed, you will be heating the screed below and the tiles above - it will literally take hours before any heat can be felt on the surface.

Therefore it's either switch it on several hours before you want the floor to be warm, or leave it on permanently.
Either way it will cost a fortune to run and achieve very little.

For cold bathroom floors, most people use these instead: http://www.dunelm.com/category/home-and-furniture/bathroom/bath-mats