New kitchen install over existing wet underfloor heating

[brianmoooore]

Screed temperature should only be a maximum of 30 odd degrees, set by the UFH mixing valve, so the increase in cable sizes isn't that great.

 

[Zlodej]

Have you asked the person who did the underfloor heating if they have a picture of it before screeding?
It is a common think they do for multiple reasons. This would give you reference points.
I wouldn't vory about heat much as any competent sparky would figure that-one easily out...