On 03/04/2018 13:16, Graham. wrote:

I only have the bare bones of this from my daughter at present.

She has new "wet" underfloor heating laid. The tiller was laying floor
tiles on the screed,, and cut through the tubing (angle grinder?).

Is this repairable, or is it a break up the floor and start again job?

Whatever make the system is .. there will be a repair joint for the pipes