Bathroom underfloor heating

[Westy]

Hi, We are in the process of refitting our downstairs bathroom, the house is a long term project with all rooms requiring renovating as well as a rear extension. Eventually we would like to have underfloor heating throughout downstairs, construction is a suspended wooden floor with a large crawl space below. With this in mind we would like to install the underfloor heating pipework in the bathroom whilst we are refitting. My plan was to remove all existing floor boards, insulate underneath with 100mm rigid insulation and run pipework on spreader trays between the joists with 18mm marine ply and tiles. My question is whether marine ply will transfer heat ok? if not what base should I be using. Thanks in advance.

 

[ShaunCorbs]

my suggestion would

to infill the joists with insulation and then internally batten for ply so you top of your joists is the new floor level

then use a Low Profile Overlay system

and then as your having tiles hardie backer over the top of that